Valor nutritivo de perfilhos e componentes morfológicos em pastos de capim-braquiária diferidos e adubados com nitrogênio Nutritive value of tillers and morphological components on deferred and nitrogen fertilized pastures of Brachiaria decumbens cv. Basilisk

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Manoel Eduardo Rozalino Santos

2010-09-01

Full Text Available Este trabalho foi realizado com o objetivo de avaliar o valor nutritivo de perfilhos e componentes morfológicos em pastos diferidos e adubados com nitrogênio de Brachiaria decumbens cv. Basilisk. Dois experimentos foram realizados em delineamento de blocos casualizados com três repetições e esquema de parcela subdivida. No primeiro experimento, foram realizadas combinações entre doses de nitrogênio (0, 40, 80 e 120 kg/ha com os componentes morfológicos (folha verde, colmo verde, folha morta e colmo morto ou com as categorias de perfilhos (vegetativo e reprodutivo do pasto. No segundo experimento, estudaram-se as combinações entre períodos de diferimento (73, 95 e 116 dias com categorias de perfilhos (vegetativo e reprodutivo. A adubação nitrogenada aumentou o percentual de fibra em detergente neutro (FDN nos colmos verdes e o teor de proteína bruta (PB nas folhas verdes e mortas e no colmo verde. Elevou também os percentuais de PB nos perfilhos vegetativos e reprodutivos, assim como o teor de FDN do perfilhos vegetativos. Maior período de diferimento causou acréscimo no percentual de FDN e redução no percentual de proteína bruta nos perfilhos vegetativos e reprodutivos. A dose de nitrogênio e o período de diferimento alteram o valor nutritivo dos componentes morfológicos e dos perfilhos dos pastos de B. decumbens cv. Basilisk. No diferimento da pastagem, ações de manejo que resultem em maiores percentuais de lâmina foliar verde e perfilho vegetativo no pasto contribuem para melhorar o valor nutritivo da forragem diferida.This work was carried out aiming to evaluate the nutritional value of tillers and the morphological components on deferred and nitrogen-fertilized pastures of Brachiaria decumbens cv. Basilisk. Two experiments were performed in randomized block designs with three repetitions and subdivided plot scheme. In the first experiment, combinations among nitrogen doses (0, 40, 80 and 120 kg/ha were performed

COMPONENTES DA PARTE AÉREA E RAÍZES DE PASTAGENS DE Brachiaria spp. EM DIFERENTES IDADES APÓS A REFORMA, COMO INDICADORES DE PRODUTIVIDADE EM AMBIENTE DE CERRADO ABOVEGROUND AND TOTAL ROOT BIOMASS COMPONENTS OF Brachiaria PASTURES IN DIFFERENT AGES AFTER RENOVATION AS A PRODUCTION INDICATOR UNDER SAVANNA VEGETATION

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Robert Michel Boddey

2007-09-01

pastures of different ages after renovation. Three B.brizantha pastures, with one, seven, and nine years after renovation through the Barreirão system, and one B. decumbens pasture twenty years after traditional renovation were evaluated. The areas were located at Goiânia, Brazil (16º35'12";S, 49º21'14";W, 730 m. The one year after renovation pasture showed the highest productivity, 197% higher than the twenty year after renovation pasture. With increasing pasture renovation age, there was a production and regrowth rate decrease due to the degradation process. This aspect may be observed in the root system development, since the total root productivity to 100 cm depth was reduced as pasture age increased, with 9.14 Mg ha-1, 4.87 Mg ha-1, and 2.90 Mg ha-1 for pastures of seven, nine, and twenty years after renovation, respectively. The one year pasture did not show appreciable root contribution. The Brachiaria regrowth pasture was found to be dependent on system N availability; hence, the litter production showed to be a good pasture degradation indicator. The N stocks down to 100 cm depth were of 7.54 Mg ha-1, 8.70 Mg ha-1, and 9.47 Mg ha-1, in the pastures with one, seven, and twenty years, respectively. These values were much lower than those in the nine year after renovation pasture (14.2 Mg ha-1.

KEY-WORDS: Brachiaria; pastures; roots; litter.

Influência da localização das fezes nas características morfogênicas e estruturais e no acúmulo de forragem em pastos de capim-braquiária Influence of localization of feces on morphogenetic and structural characteristics and forage accumulation on Brachiaria decumbens pastures

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Manoel Eduardo Rozalino Santos

2011-01-01

Full Text Available Objetivou-se avaliar as características morfogênicas e estruturais e o acúmulo de forragem em pastos de Brachiaria decumbens (capim-braquiária de acordo com a localização das fezes de bovinos. Foram avaliadas duas áreas da pastagem: próxima e distante das fezes. O delineamento foi em blocos casualizados, com três repetições. Foram marcados perfilhos no pasto para avaliação do comprimento de folhas e colmos. O aparecimento e a morte de folhas também foram registrados. A taxa de alongamento de colmo foi 80% maior e a taxa de alongamento foliar 23% maior nos perfilhos das áreas próximas das fezes. O filocrono também foi maior nos perfilhos (8,5 dias das áreas próximas às fezes em comparação àqueles de áreas distantes (7,7 dias. Não houve efeito da localização das fezes sobre a taxa de senescência foliar (0,39 cm/perfilho.dia e a duração de vida da folha (38 dias. O comprimento final da lâmina foliar foi 25% maior nos perfilhos localizados próximos às fezes. O número de folhas com desfolhação (1,3 folhas foi menor nas áreas próximas às fezes, contrariamente ao número de folhas mortas (2,8 folhas. O comprimento do pseudocolmo aumentou 73% com a proximidade das fezes. Os números de perfilhos vegetativos, mortos e total foram maiores nas áreas distantes das fezes. Maior taxa de crescimento total do capim-braquiária também ocorreu nas áreas próximas às fezes. A deposição de fezes bovinas modifica as características morfogênicas e a estrutura do pasto de B. decumbens. Nas regiões próximas às fezes, o fluxo de tecidos é mais intenso e o acúmulo de forragem é maior.The objective of this study is to evaluate morphogenetic and structural characteristics as well as forage accumulation on Brachiaria decumbens pastures according to the site of cattle feces. It was evaluated two grazing areas: near and far from the droppings. The design used was a random block design, with three replicates. Tillers were

Desempenho do feijoeiro consorciado com espécies de braquiária em função de doses de fluazifop-p-butil The effect of fluazifop-p-butyl doses on the performance of the common bean plant intercropped with brachiaria species

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A.J. Carvalho

2012-06-01

Full Text Available Para avaliar o efeito de doses de fluazifop-p-butil no desempenho do feijoeiro consorciado com braquiária, foi conduzido um experimento em Coimbra, MG, nas safras da seca de 2007 e das águas de 2007-2008. Foi utilizado o delineamento em blocos casualizados, com quatro repetições. Os tratamentos foram dispostos em esquema fatorial, envolvendo duas espécies de braquiária (Brachiaria brizantha e B. decumbens, seis doses de fluazifop-pbutil (0; 7,81; 15,62; 31,25; 62,50; e 125,00 g ha-1, mais o monocultivo de ambas as culturas. O feijoeiro foi plantado a 0,5 m entre linhas, com as sementes de braquiária sendo semeadas nas mesmas fileiras do feijão. Nos sistemas consorciados, além das doses de fluazifop-pbutil, utilizou-se fomesafen (125 g ha-1 e bentazon (336 g ha-1. Para o feijão solteiro foi utilizada uma mistura dos herbicidas fomesafen (125 g ha-1 e fluazifop-p-butil (100 g ha-1. Foram avaliados o estande final de plantas e o rendimento de grãos do feijoeiro com seus componentes primários. Os dados foram submetidos à analise de variância, sendo os efeitos das espécies de braquiária e das safras estudados pelo teste F, e os efeitos das doses de fluazifop-p-butil, por análise de regressão. Conclui-se que B. decumbens é mais competitiva com o feijão que B. hrizantha. Na safra da seca, a utilização de 7,81 g ha-1 de fluazifop-p-butil no consórcio com B. decumbens proporciona rendimento de grãos de feijão equivalente ao do monocultivo. O consórcio com B. brizantha dispensa o uso do herbicida. Na safra das águas, independentemente da espécie de braquiária, é necessária a aplicação de 31,25 g ha-1 de fluazifop-p-butil.To evaluate the effect of fluazifop-p-butyl doses on the performance of bean intercropped with brachiaria species, an experiment was conducted in Coimbra, MG, during the 2007 dry season and 2007-2008 rainy season crops. The experiment was arranged in a randomized block design with four replications. The

Fitorremediação de solos contaminados com arsênio (As utilizando braquiária Phytoremediation of arsenic-contaminated soils using Brachiaria grass

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Alessandra Silveira Antunes Araújo

2011-02-01

Full Text Available Conduziu-se este trabalho, com o objetivo de avaliar o potencial fitoextrator de arsênio (As da Brachiaria decumbens Stapf., cultivada em casa de vegetação, utilizando-se seis solos: Latossolo Amarelo Distrófico (LAd, Latossolo Vermelho Distrófico (LVd, Neossolo Flúvico (RU, Neossolo Quartzarênico (RQ, Gleissolo Háplico (GX e Gleissolo Melânico (GM. O As foi adicionado aos solos na forma de arsenato de sódio heptahidratado nas doses 0, 25, 50, 200 e 800 mg kg-1. As plantas foram coletadas 55 dias após a semeadura, separadas em parte aérea e raiz e, após secagem do material em estufa, o mesmo foi digerido segundo o método 3051 da USEPA, sendo o teor de As determinado por espectrofotometria de absorção atômica (EEA com forno de grafite. Observou-se redução no desenvolvimento da braquiária de forma diferenciada nas seis classes de solo. Houve baixa translocação do As, da raiz para a parte aérea, sendo essa espécie considerada tolerante ao elemento e não hiperacumuladora, podendo ser utilizada em programas de revegetação de áreas contaminadas pelo elemento.This work evaluated the phytoextraction potential of arsenic (As by Brachiaria decumbens growing under greenhouse conditions in six soils: a Dystrophic Yellow Latosol (LAd, a Dystrophic Red Latosol (LVd, a Fluvic Neosol (RU, a Quartzenic Neosol (RQ, a Haplic Gleysol (GX, and a Melanic Gleysol (GM. Arsenic was added to the soils as sodium arsenate heptahydrate (Na2HAsO4.7H2O at the following doses: 0, 25, 50, 200, and 800 mg kg-1. The plants were collected 55 days after planting for determination of shoot and root dry matter production. Arsenic shoot and root contents were evaluated after digestion according to the USEPA 3051A method, following analysis by graphite furnace atomic absorption spectroscopy. Plant development was differently affected by As in the six different soil classes. There was low translocation of As and consequently most of the As was detected in the

Crescimento de espécies do gênero Brachiaria sob alagamento em casa de vegetação Effect of flooding on the growth of Brachiaria species in greenhouse

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Jorge Luiz Schirmer de Mattos

2005-06-01

Full Text Available Objetivou-se avaliar a tolerância ao alagameto de quatro espécies de Brachiaria (B. decumbens,B. brizantha, B. humidicola e B. mutica, a partir de suas características morfogênicas, fisiológicas e produtivas. Os tratamentos foram arranjados segundo esquema fatorial 4 x 3 quatro espécies de Brachiaria e três níveis de disponibilidade de água no solo (capacidade de campo, lâmina d'água de 1 e 10 cm acima do solo. O delineamento experimental foi de blocos completos ao acaso, com três repetições. O experimento foi instalado em casa de vegetação, utilizando-se colunas de PVC com 60 cm de altura x 30 cm de diâmetro. Os níveis de alagamento foram impostos a partir do 22º dia de rebrota após corte de uniformização. O acréscimo de água aos vasos, necessário para satisfazer a lâmina d'água a 1 e 10 cm do nível do solo nos respectivos vasos, foi controlado com o auxílio de furos presentes nas paredes dos vasos a 1 e 10 cm acima do nível do solo, respectivamente. O alagamento comprometeu a taxa de alongamento e acentuou a taxa de senescência das lâminas foliares, independentemente da espécie. Observou-se controle estomático das trocas gasosas em folhas de todas as espécies. O alagamento reduziu a fotossíntese líquida das espécies de Brachiaria, exceto de B. mutica, que superou as demais espécies sob a lâmina d'água de 10 cm acima do solo. Também diminuiu significativamente a área e o peso das lâminas foliares verdes, exceto em B. mutica, que apresentou apenas ligeira tendência de queda. A B. muticaapresentou numerosas raízes adventícias, que, possivelmente, lhe conferiram superior tolerância ao alagamento.This study aimed to evaluate the tolerance of four Brachiaria species (B. decumbens,B. brizantha, B. humidicola and B. mutica to flooding with regard to their morphogenetical, physiological and production characteristics. The experimental treatments resulted from a 4 x 3 factorial arrangement of four

Enzimas fibrolíticas exógenas en la digestibilidad in vitro de cinco ecotipos de Brachiaria

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Juan H. Avellaneda-Cevallos

2007-01-01

Full Text Available En zi mas fi bro lí ti cas exó ge nas en la di ges ti bi li dad in vi tro de cin co eco ti pos de Bra chia ria. Este experimento se llevó a cabo en la Estación Experimental del Colegio de Postgraduados, en Montecillo, Estado de México, México, durante el 25 abril y el 27 noviembre de 2002. Se usó la primera fase de la técnica de Tilley y Terry (3, 6, 12, 24, 48, 72 h incubación con el objetivo de medir el efecto de un compuesto enzimático fibrolítico exógeno (enzima; Fibrozyme®; 0 y 1,5 g enzima/kg MS en la digestibilidad in vitro (DIV de MS, FDN y FDA de henos de cinco ecotipos de Brachiaria [brizantha var. Toledo (BT; ruziziensis x decumbens CIAT 46024 (RD; decumbens var. Señal (DS; ruziziensis x brizantha CIAT 36061 cv. Mulato (RBM; brizantha var. Insurgente (BI]. La DIVMS a las 48 y 72 h, para 0 y 1,5 g enzima, fue mayor (p<0,05 para los ecotipos BT y BI, respecto a RD, DS y RBM. La DIVFDN a las 48 y 72 h, para 0 y 1,5 g enzima, fue mayor (p<0,05 para BT y BI, respecto a RD, DS y RBM. La enzima aumentó (p<0,05 la DIVFDN sólo para el ecotipo RD a las 72 h; además, incrementó la DIVFDA para BT a 12 h; BT y DS a 24 h; BT, RD y BI a 48 h. Por tanto, las enzimas fibrolíticas aumentaron la digestibilidad in vitro de la pared celular de cinco ecotipos de Brachiaria.

Evaluación agronómica de accesiones de Brachiaria spp. en condiciones agroecológicas de Barrancabermeja, Santander, Colombia.: II. Segundo año de evaluación. Agronomic evaluation of accessions of Brachiaria spp. under the agroecological conditions of Barrancabermeja, Santander, Colombia.: II. Second year of evaluation.

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E.R Canchila

2008-06-01

Full Text Available La presente investigación se desarrolló con el objetivo de evaluar el comportamiento agronómico (a partir del segundo año de producción de una colección de accesiones de Brachiaria spp. para seleccionar aquellas de mejor adaptación a las condiciones agroecológicas de la región Santandereana de Barrancabermeja. Los cor­tes se realizaron cada 42 días, después de concluir el primer año de evaluación. Se determinó la altura de la planta, la producción de forraje, el porcentaje de hojas y la incidencia de enfermedades. Según el ACP los indicadores más influyentes fueron: la producción de forraje y el porcentaje de hojas; no se presentaron afectaciones por plagas y enfermedades. Se destacaron, por presentar valores superiores a la media poblacional, las accesiones: B. dictyoneura (CIAT-6133, B. brizantha (CIAT-16488, CIAT-16212, CIAT-16121 y CIAT­16322 y B. decumbens (CIAT-606; mientras que las de menor adaptación y productividad fueron: B. ruziziensis CIAT-26180; B. brizantha CIAT-16315, CIAT-16327 y CIAT-6387; B. decumbens CIAT-16497; y B. humidicola CIAT-26159, CIAT-16871, CIAT-16867 y CIAT-26427. Se recomienda difundir, de manera progresiva, las accesiones destacadas para su uso en los ecosistemas ganaderos.This research was carried out with the objective of evaluating the agronomic performance (from the second year of production of a collection of Brachiaria spp. accessions, in order to select those of better adaptation to the agroecological conditions of the Santander region of Barrancabermeja. The cuttings were performed every 42 days, after concluding the first year of evaluation. Plant height, forage production, leaf percentage and disease incidence were determined. According to the MCA the most influencing indicators were: forage production and leaf percentage; no affectations by pests and diseases were present. The accessions B. dictyoneura (CIAT-6133, B. brizantha (CIAT-16488, CIAT-16212, CIAT-16121 and CIAT-16322 and

Uso de n-alcanos na estimativa da composição botânica da dieta em ovinos alimentados com diferentes proporções de Brachiaria decumbens Stapf e Arachis pintoi Koprov e Gregory Use of n-alkanes to estimate the dietary botanical composition in sheep fed different proportions of Brachiaria decumbens Stapf and Arachis pintoi Koprov and Gregory

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Nelson Massaru Fukumoto

2007-08-01

Full Text Available Neste experimento objetivou-se avaliar o poder discriminatório dos n-alcanos para estimar com acurácia e precisão a composição botânica da dieta em ovinos alimentados com diferentes proporções de Arachis pintoi Koprov & Gregory cv. Amarillo (0, 15, 30, 45 e 60% e Brachiaria decumbens Stapf. Foram utilizados 20 ovinos em delineamento inteiramente casualizado, com período experimental de dez dias de adaptação à dieta e cinco dias de coleta de fezes. Nas amostras (compostas de fezes do período e nos fenos, foi analisada a concentração de n-alcanos. Para o cálculo da composição botânica, utilizou-se minimização da soma dos quadrados dos desvios, considerando as concentrações dos alcanos nos componentes da dieta e nas fezes. Para a escolha dos alcanos mais discriminatórios, foram utilizadas as análises multivariadas e as variáveis canônicas. As estimativas calculadas foram submetidas à análise de variância. As médias foram comparadas pelo teste t e as correções dos valores estimados em relação aos valores reais foram ajustadas em regressão linear. As variáveis canônicas indicaram que os alcanos C35, C33, C30, C31, C27, C29 e C36 são os de maior potencial discriminatório. O uso desses alcanos nos cálculos foi mais acurado e preciso para estimar a proporção de A. pintoi na dieta que o uso de apenas dois ou três alcanos com poder discriminatório. O melhor ajuste da regressão também foi encontrado para esses alcanos. O teste t para o intercepto da equação (a e o coeficiente de regressão (b indicaram que a = 0 e b = 1, comprovando que os valores estimados são equivalentes aos valores reais. As análises multivariadas mostraram-se ferramentas de grande importância na escolha dos n-alcanos nos cálculos nas estimativas.The objective of this experiment was to use n-alkane to estimate accurately and precisely the botanical composition of dietary forage in sheep fed different proportions of Arachis pintoi

Atributos físico-hídricos de um Latossolo após a aplicação de lodo de esgoto em área degradada do Cerrado Hydro-physical attributes of an Oxisol after sewage sludge application on a Cerrado degraded area

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Fabiana da Silva de Campos

2011-05-01

Full Text Available Os solos cultivados intensivamente e inadequadamente são degradados, assim como a construção de obras civis no meio rural executada sem atender à legislação. O trabalho objetivou definir a interferência do lodo de esgoto na recuperação de atributos de um Latossolo Vermelho. O experimento foi implantado em 2004, em Selviria (MS. Os tratamentos utilizados foram: T1-vegetação de cerrado; T2-solo exposto sem tratamento para recuperação; T3-solo cultivado com eucalipto e braquiária sem o uso do lodo de esgoto e adubação mineral; T4-solo cultivado com eucalipto e braquiária com adubação mineral; T5-solo cultivado com eucalipto e braquiária com uso de 30Mg ha-1 de lodo de esgoto e; T6-solo cultivado com eucalipto e braquiária com uso de 60Mg ha-1 de lodo de esgoto. Nas camadas do solo de 0,00-0,05; 0,05-0,10; 0,10-0,20 e de 0,20-0,30m, foram avaliados os atributos físico-hídricos e teor de matéria orgânica. Os tratamentos com adubação mineral e orgânica estão agindo de forma semelhante para a recuperação dos atributos físico-hídricos e do teor de matéria orgânica. Em solos degradados pela construção de obras civis a aplicação de 30 a 60mg de lodo de esgoto ha-1 recupera as suas propriedades físico-hídricas.Intensively and inadequately managed soils and the civil construction industry in the rural area that are unconcerned with specific legislation, result in several problems in the environment. The objective of the present study was to evaluate the influence of sewage sludge on the recovery of hydro-physical properties of an Oxisol. The experiment was implanted in 2004, in Selvíria, Mato Grosso do Sul, Brazil. The six experimental treatments were arranged according to a randomized complete-block design with four replications. The experimental treatments were: 1 - Native Cerrado vegetation; 2 - degraded soil without treatment for soil recovery; 3 - Eucalyptus citriodora planting and Brachiaria decumbens sowing

Redução da interferência de Brachiaria decumbens na formação de pastagem com Penisetum purpureum através de herbicidas Reduction of Brachiaria decumbens interference on Pennisetum purpureum pasture establishment through herbicides

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W. Silva

2002-08-01

Full Text Available A tolerância da gramínea forrageira capim-elefante a herbicidas aplicados isoladamente ou em misturas entre si, aplicados em condições de pré e pós-emergência da forrageira, bem como a eficiência desses produtos no controle de B. decumbens e outras espécies de plantas daninhas, foram avaliadas em dois experimentos. Os herbicidas aplicados no experimento conduzido em condições de pré-emergência do capim-elefante, com as respectivas doses em kg ha-1, foram: metolachlor (1,152; 2,304; e 3,456, oxyfluorfen (0,48; 0,96 e 1,44 e a formulação comercial de atrazine + metolachlor (1,25; 2,50; e 3,75, três repetições. Os herbicidas aplicados no experimento instalado em condições de pós-emergência da forrageira, com as respectivas doses em kg ha-1,foram: ametryne (1,25; 2,50; e 3,75 e oxyfluorfen (0,48; 0,96; e 1,44, com quatro repetições. Os tratamentos foram distribuídos em blocos ao acaso; sendo que, em ambos os experimentos foram adicionadas as testemunhas (capinada e sem capina, e os cultivares de capim-elefante utilizados em ambos os experimentos foram Cameroon e Pioneiro. A aplicação dos herbicidas em pré-emergência da forrageira foi feita um dia após o plantio com solo úmido; no experimento em pós-emergência do capim-elefante os herbicidas foram aplicados sobre o topo das plantas da cultura forrageira, aos 20 dias após a emergência. Metolachlor e atrazine + metolachlor, em pré-emergência, foram seletivos para os dois cultivares testados. O oxyfluorfen, até 0,96 kg ha-1, foi seletivo para a cultura forrageira nas aplicações tanto em pré- como em pós-emergência. O ametryne, em pós-emergência, também foi seletivo aos cultivares na dose inferior a 2,50 kg ha-1. B. decumbens e B. brizantha foram eficientemente controladas (90,9% em pré-emergência, exceto na menor dose de metolachlor e atrazine + metolachlor. O controle das dicotiledôneas atingiu 85% com metolachlor, atrazine + metolachlor e oxyfluorfen

Fontes, doses e modos de aplicação de fósforo na recuperação de pastagem com brachiaria Sources, doses, and application method of phosphorus in the recovery of brachiaria pasture

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Alfredo Yuji Ieiri

2010-10-01

Full Text Available Objetivando-se avaliar diferentes fontes, doses e métodos de aplicação de fósforo na recuperação da Brachiaria decumbens, um experimento foi conduzido na Fazenda Caminho das Pedras, município de Uberlândia-MG, em Latossolo Vermelho distrófico, textura média, entre novembro de 2003 e abril de 2004. Os tratamentos constaram de três fontes de fósforo (Superfosfato Triplo, Termofosfato magnesiano e hiperfosfato de Gafsa nas dosagens de 0; 50; 100 e 150 kg ha-1 de P2O5, com manejo incorporado e não incorporado, em três repetições, no delineamento de blocos casualizados. Foram utilizadas parcelas de 2,0 x 5,0 m, as quais foram adubadas uniformemente com 330 kg ha-1 de N e 220 kg ha-1 K2O, na forma de uréia + sulfato de amônio e cloreto de potássio, respectivamente. Foi avaliada a produtividade da Brachiaria em três cortes da parte aérea, em um intervalo de 30 dias entre os cortes. A aplicação de fósforo com diferentes fontes e doses promoveu incremento na produtividade da Brachiaria, porém não houve diferença comparando-se os métodos de aplicação. A maior resposta foi obtida com 150 kg ha-1 de P2O5, na forma de superfosfato triplo com produtividade média de 2997 kg ha-1 de MS por corte, e a menor produtividade ocorreu no tratamento com 50 kg ha-1 de P2O5 na forma de hiperfosfato de Gafsa. Houve aumento na porcentagem do fósforo foliar e do fósforo no solo, com aumento da dose em todas as fontes, em ambos extratores. Na avaliação dos extratores, o Mehlich-1 apresentou maior extração na fonte hiperfosfato de Gafsa, contrariando os resultados de produção.The objective of this work was to evaluate different sources, doses and methods of phosphorus application in the recovery of Brachiaria decumbens. An experiment was installed on the "Caminho das Pedras" Farm, in Uberlândia-MG, in Acroustox soil, medium texture, between November 2003 and April 2004. The treatments were three phosphorus sources (Triple Superphosphate

Identificação de isolados de Azospirillum amazonense associados a Brachiaria spp., em diferentes épocas e condições de cultivo e produção de fitormônio pela bactéria Identification of Azospirillum amazonense isolates associated to Brachiaria spp. at different stages and growth conditions, and bacterial plant hormone production

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F. B. Reis Junior

2004-02-01

Full Text Available Existem evidências de que pastagens formadas por algumas espécies do gênero Brachiaria poderiam beneficiar-se com o processo de fixação biológica do nitrogênio atmosférico (FBN, garantindo a estas pastagens maior longevidade. Dentre as bactérias diazotróficas encontradas em associação com estas gramíneas forrageiras, destaca-se a espécie Azospirillum amazonense. Neste trabalho, objetivou-se verificar a influência da espécie de Brachiaria, manejo da pastagem e sazonalidade sobre as populações de A. amazonense associadas às raízes destas plantas. Diferentes pastagens (B. humidicola, B. decumbens e B. brizantha foram introduzidas em regiões do ecossistema Cerrado e de Mata Atlântica. Foram avaliados dois sistemas de manejo com diferentes taxas de lotação, e as coletas foram realizadas em diferentes épocas do ano. As populações de A. amazonense foram quantificadas e a identidade dos isolados confirmada, assim como sua capacidade de produção de fitormônios tipo AIA (ácido 3-indol acético em meio de cultivo. Isolados de A. amazonense foram obtidos a partir de amostras de raízes das três espécies de Brachiaria avaliadas. Estimativas das populações desta bactéria variaram de 10³-10(7 células g-1 de raízes. Em amostras do ecossistema Cerrado, a época de coleta apresentou efeito significativo sobre a população destas bactérias. Os dados da região de Mata Atlântica mostraram que plantas de Brachiaria de diferentes espécies e pastagens sob diferentes taxas de lotação podem apresentar números populacionais distintos associados às suas raízes. A técnica de análise de restrição do DNA ribossomal amplificado (ARDRA confirmou a identidade de todos os isolados avaliados. Estes isolados foram capazes de produzir fitormônios tipo AIA.There is evidence that pastures formed by some species of the genus Brachiaria could be benefited by the biological nitrogen fixation process (BNF, which would give these

Predição da degradação da matéria seca pelo volume de gases utilizando a técnica in vitro semi-automática de produção de gases Prediction of dry matter degradation from volume of gas production using the in vitro semi-automatic gas production technique

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Ú.T. Nogueira

2006-10-01

Full Text Available Estimou-se a degradação da matéria seca (DMS via produção de gases (PG por meio de equações. Foram agrupados dados de volume de gases e DMS de oito forrageiras (Brachiaria brizantha, Brachiaria decumbens, feno de Cynodon spp, silagem de milho, silagem de milheto, sorgo de corte, capim-elefante e cana-de-açúcar e de milho em grão. Os dados de DMS obtidos em laboratório foram comparados à DMS obtida pelas equações de regressão. Apesar dos altos coeficientes de determinação, os resultados demonstraram a impossibilidade de estimar a DMS via PG pelas equações geral, de dois e de três pontos.The dry matter degration (DMD was estimated through volume of gas produced (GP during the in vitro fermentation. The DMD from eight forages (Brachiaria brizantha, Brachiaria decumbens, cynodon hay, maize silage, Pennisetum glaucon, sorghum, elephant grass and sugarcane and corn grain were obtained and were compared with the DMD estimated using regression equations. The results showed the GP can not predict the DMD due to inocula effects, chemical composition of substrate or losses of particles of soluble material during filtration process.

Phytochemical and Biological Properties of Ajuga decumbens ...

African Journals Online (AJOL)

Zhang B, Zeng FJ, Zhang XY. Study on anti-infection effect of Ajuga decumbens. Chin J Nosocomiol 2014;. 24: 2937-3939. 52. Li M, Peng WH. Chemical constituents and pharmacological research progress of Ajuga decumbens. J pr tradit Chinese mede 2012; 28: 322-. 323. 53. Ma SC, Du J, But PPH, Deng XL, Zhang YW, ...

Avaliação da Brachiaria brizantha cv. marandu em sistemas silvipastoris Evaluation of Brachiaria brizantha cv. marandu in silvopastoral systems

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G.R. Moreira

2009-06-01

Full Text Available Avaliou-se a degradabilidade in situ da matéria seca (MS da Brachiaria brizantha cv. marandu colhida em dois sistemas silvipastoris compostos pelas arbóreas, ipê felpudo (Zeyheria tuberculosa e aroeira (Myracrodruon urundeuva, localizados no bioma Cerrado, município de Lagoa Santa, MG. O período de coleta da forragem foi de dezembro de 2004 a abril de 2005. O delineamento utilizado foi em blocos ao acaso, segundo esquema de parcelas subdivididas, sendo as parcelas os tratamentos e as sub-parcelas os tempos de degradação. O sombreamento com as arbóreas não influenciou a degradabilidade in situ da matéria seca da forrageira.In situ degradability of dry matter of Brachiaria brizantha cv. marandu harvested in two silvopastoral systems was evaluated. One system was composed by Zeyheria tuberculosa tree and the other by Myracrodruon urundeuva, both located at Brazilian Savannah, Lagoa Santa, MG. A completely ramdomized block experimental design in a splitplot arrangement was used. The treatments were allocated in the plots and the times in the splitplot. No effect of shade was observed for in situ dry matter degradability.

Crescimento de espécies de Brachiaria sob déficit hídrico e alagamento a campo Effect of water deficit and flooding on the growth of Brachiaria species in the field

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Jorge Luiz Schirmer de Mattos

2005-06-01

Full Text Available Dois experimentos foram conduzidos, sendo um instalado em área de encosta e outro em área de baixada. Objetivou-se avaliar a tolerância à seca e ao alagamento de três espécies comerciais de Brachiaria (B. decumbens cv. Basilisk, B. brizantha cv. Marandu e B. mutica e três acessos (B. brizantha B-11, B. humidicola cv. Tupi e B. dictyoneura, a partir de suas características morfogênicas, produtivas e relações hídricas. O delineamento experimental foi o de blocos ao acaso, com seis repetições. As parcelas, com 4 m² de área total, foram constituídas de oito linhas de 2 m de comprimento, com espaçamento entre linhas de 0, 25 m. Dezenove dias após corte de uniformização, a área localizada na baixada foi submetida ao alagamento de uma lámina d'àgua de 56 mm de água, por 30 dias; simultaneamente, suspendeu-se a irrigação na área de encosta sob déficit hídrico. O alagamento foi mais prejudicial às características morfogênicas que déficit hídrico. Enquanto a taxa de alongamento foliar de todas as espécies foi mais baixa sob alagamento, as taxas de aparecimento e senescência foliares responderam ao estresse hídrico conforme a espécie. A taxa de aparecimento de folhas foi mais comprometida pelo alagamento apenas em B. dictyoneura, B. mutica e B. brizantha cv. Marandu. As maiores taxas de senecência de folhas ocorreram sob alagamento, particularmente em B. decumbens, B. brizantha cv. Marandu e B-11. Os estresses hídricos tiveram efeitos diferenciados sobre as características produtivas das espécies. A produção de biomassa verde aérea foi maior em B-11 sob regime de déficit hídrico, enquanto em B. dictyoneura e B. mutica, observou-se tendência de valores mais altos sob regime de alagamento. O índice de área foliar foi mais alto sob deficit hídrico, apenas em B. brizantha Marandu e B-11. A população de perfilhos basilares foi maior sob alagamento apenas em B. dictyoneura.Two experiments were carried out

Recovery of hillside soils, degraded by the erosion, by means of the use of biological-forest procedures

International Nuclear Information System (INIS)

Leon Moreno, Clara Esperanza

1998-01-01

Soil degradation is present in some areas of the Guanenta Comunero province in Andean Region of Colombia. Different responsible factors are identified: inadequate soil management (tilling in slope direction), machinery overuse and monoculture without natural cover. This carried out erosion that is severe in 40% of the affected area with furrows, gullies and barrens occurrence. For prevent the erosion were built wood barriers, established whit gramineous, leguminous and trees. The gramineous, Brachiaria decumbens was established using seeds a live material, which produced 1860, and 1631 kg/ha of dry material respectively. Arachis pintoi established like protein bank and in association reached a soil coverage of 87 % and improved disposability of Ca, Mg, K and P. farmers can easily build wooden barriers and them can retain sediments un amounts of 4.72, 23.43 and 1.50 m 3 in areas of 207,494 and 129 m 2 respectively

Accuracy of two optical chlorophyll meters in predicting chemical composition and in vitro ruminal organic matter degradability of Brachiaria hybrid, Megathyrsus maximus, and Paspalum atratum

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Martin P. Hughes

2017-03-01

Full Text Available The objective of this study was to determine the accuracy and reliability of 2 optical chlorophyll meters: FieldScout CM 1,000 NDVI and Yara N-Tester, in predicting neutral detergent fibre (NDF, acid detergent fibre (ADF, acid detergent lignin (ADL, acid detergent insoluble nitrogen (ADIN and in vitro ruminal organic matter degradability (IVOMD of 3 tropical grasses. Optical chlorophyll measurements were taken at 3 stages (4, 8 and 12 weeks of regrowth in Brachiaria hybrid, and Megathyrsus maximus and at 6 and 12 weeks of regrowth in Paspalum atratum (cv. Ubon. Optical chlorophyll measurements showed the highest correlation (r = 0.57 to 0.85 with NDF concentration. The FieldScout CM 1,000 NDVI was better than the Yara N-Tester in predicting NDF (R2 = 0.70 and ADF (R2 = 0.79 concentrations in Brachiaria hybrid and NDF (R2 = 0.79 in M. maximus. Similarly, FieldScout CM 1,000 NDVI produced better estimates of 24 h IVOMD (IVOMD24h in Brachiaria hybrid (R2 = 0.81 and IVOMD48h in Brachiaria hybrid (R2 = 0.65 and M. maximus (R2 = 0.75. However, these prediction models had relatively low concordance correlation coefficients, i.e., CCC >0.90, but random errors were the main source of bias. It was, therefore, concluded that both optical chlorophyll meters were poor and unreliable predictors of ADIN and ADL concentrations. Overall, the FieldScout CM 1,000 NDVI shows potential to produce useful estimates of IVOMD24h and ADF in Brachiaria hybrid and IVOMD48h and NDF concentrations in M. maximus.

Características estruturais do pasto de capim-braquiária de acordo com a localização das fezes Structural characteristics of Brachiaria grass pasture according to the location of feces

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Manoel Eduardo Rozalino Santos

2010-10-01

Full Text Available Objetivou-se avaliar o efeito da localização das fezes de bovinos sobre as características de perfilhos vegetativos e reprodutivos, a massa dos componentes da planta, a densidade volumétrica da forragem e a altura do pasto de Brachiaria decumbens, cv. Basilisk, manejado sob lotação contínua. O delineamento foi em blocos casualizados, com três repetições, em esquema de parcela subdivida, considerando parcelas os locais próximos e distantes das fezes e subparcelas as categorias de perfilhos vegetativos e reprodutivos. A massa de lâmina foliar viva (LFV por perfilho em locais próximos às fezes (0,14 g foi maior que nos locais distantes das fezes (0,08 g, contrariamente ao verificado para a composição de massa de lâmina foliar morta por perfilho. A massa de LFV nos perfilhos vegetativos (0,15 g foi maior que nos perfilhos reprodutivos (0,06 g. Por outro lado, a massa de colmo (0,38 g e de lâmina foliar morta (0,20 g foi maior nos perfilhos reprodutivos. O peso dos perfilhos das plantas próximas às fezes foi maior (0,58 g que daqueles distantes das fezes (0,17 g. Em locais próximos das fezes, o número de perfilhos vegetativos foi menor, enquanto o de perfilhos reprodutivos foi maior. Maiores massas de colmo verde, forragem verde e forragem total do pasto foram observados nos locais próximos das fezes, quando comparadas aos distantes. Mesmo resultado foi obtido para a altura do pasto. A estrutura do pasto de Brachiaria decumbens é modificada pela localização das fezes dos bovinos em pastejo. A deposição de fezes por bovinos constitui fator de heterogeneidade espacial da vegetação em pastagem.The objective of this study was to evaluate the effect of the cattle feces location on the characteristics of vegetative and reproductive tillers, dry mass content in plant components, forage volumetric density and Brachiaria decumbens cv. Basilisk pasture height managed under continuous stocking. It was used a randomized block design

Effect of inclusion of oyster mushroom substrate on the in vitro fermentation kinetics of Brachiaria brizantha hay

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Ricardo da Silva Oliveira

2015-07-01

Full Text Available The objective of this study was to evaluate the effect of inclusion of exhausted substrate of Pleurotus ostreatus on the in vitro fermentation of Brachiaria brizantha hay-based diets. The experiment was conducted using the semi-automated gas production technique. The ruminal inoculum was collected from three fistulated cattle kept on Brachiaria brizantha pasture. Brachiaria brizantha hay and exhausted substrate of Pleurotus production were used for composition of the diets: ES (100% exhausted substrate, BH (100% Brachiaria brizantha hay, ES5 (5% ES + 95% BH, ES20 (20% ES + 80% BH, and ES30 (30% ES + 70% BH. The experimental design was a 5x3 factorial scheme consisting of five treatments and three ruminal inocula. The degradation kinetics of dry matter (DM was determined after 96 hours of fermentation [D (96h]. No significant differences in the cumulative volume of gas (A were observed between BH (262.6 mL/g DM, ES5 (284.3 mL/g MS, ES20 (256.6 mL/g MS and ES30 (261.7 mL/g MS, indicating that inclusion of the substrate did not affect hay fermentation. A lower gas volume (165.9 mL and lower degradability (52% were observed for the ES diet, showing a lower nutritional value of this substrate compared to Brachiaria brizantha hay, probably due to the action of enzymes that degrade structural carbohydrates found in the mycelia of Pleurotus. The ES diet exhibited a shorter colonization time (L=2.6 h; P<0.05, a finding that may be attributed to the interaction between the mycelium and substrate, facilitating initial colonization. The inclusion of exhausted substrate did not increase microbial growth or degradation compared to the BH diet, but seems to have favored initial colonization of this substrate. The use of ES does not negatively affect colonization and may be used as an ingredient of ruminant diets.

Lixiviação e degradação de diuron em dois solos de textura contrastante = Leaching potential and degradation of diuron in two soils of contrasting texture

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Miriam Hiroko Inoue

2008-12-01

Full Text Available Objetivou-se estudar a lixiviação do diuron em colunas de solo, além do efeito de métodos de redução da atividade microbiana na degradação deste herbicida em amostras de LATOSSOLO VERMELHO Distrófico (LVd – textura franco-arenosa e LATOSSOLO VERMELHO Distroférrico (LRd – textura argilosa. Para avaliar a movimentação do diuron(0; 1,6 e 3,2 kg ha-1, foram aplicadas lâminas de 0, 20, 40, 60 e 80 mm de água. Na degradação, os métodos de restrição empregados foram: autoclavagem prévia, aplicação de brometo de metila, amoxicilina, captan e amoxicilina+captan, sendo que as amostras foram mantidas na ausência ou presença de luz. Resultados indicam que lâminas superiores a 60 mm foram suficientes para promover movimentação nítida nas amostras de LVd. Para o LRd, independente da lâmina aplicada, a movimentação do herbicida ficou restrita à camadasuperficial. Nos ensaios de degradação, para o LRd, verificou-se que o acúmulo de biomassa do bioindicador Brachiaria decumbens foi maior nas amostras de solo que não receberam nenhum método de restrição. Amostras de LVd que receberam qualquer um dos métodos de restrição e foram mantidas na luz proporcionaram menor produção de biomassa, emcomparação aos demais tratamentos. Evidenciou-se, ainda, que, independente do solo, o acúmulo de biomassa de B. decumbens foi maior nas amostras que permaneceram na luz.This research was aimed at studying the leaching of diuron in soilcolumns, as well as the effect of different methods of reduction of microbial activity on diuron degradation in samples of a sandy loam soil (LVd and a clay soil (LRd. To measure the downward movement of diuron (0; 1.6 and 3.2 kg ha-1, water layers of 0, 20 40, 60 and80 mm were applied. For degradation studies, the methods used to restrict were as follow: sterilized in autoclave, methyl bromide application, amoxicillin, captan and amoxicilin+captan; soil samples were kept with or without light

Abnormal pollen mitoses (PM I and PM II) in an interspecific hybrid ...

Indian Academy of Sciences (India)

Unknown

sporocytes and pollen grains were prepared by squashing and stained with 0.5% propionic carmine. All meiotic phases and stages of pollen development were evaluated. More than 6000 microspores and pollen grains were care- fully analysed. Keywords. Brachiaria decumbens; Brachiaria ruziziensis; interspecific hybrid; ...

Potential of grasses and rhizosphere bacteria for bioremediation of diesel-contaminated soils

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Melissa Paola Mezzari

2011-12-01

Full Text Available The techniques available for the remediation of environmental accidents involving petroleum hydrocarbons are generally high-cost solutions. A cheaper, practical and ecologically relevant alternative is the association of plants with microorganisms that contribute to the degradation and removal of hydrocarbons from the soil. The growth of three tropical grass species (Brachiaria brizantha, Brachiaria decumbens and Paspalum notatum and the survival of root-associated bacterial communities was evaluated at different diesel oil concentrations. Seeds of three grass species were germinated in greenhouse and at different doses of diesel (0, 2.5, 5 and 10 g kg-1 soil. Plants were grown for 10 weeks with periodic assessment of germination, growth (fresh and dry weight, height, and number of bacteria in the soil (pots with or without plants. Growth and biomass of B. decumbens and P. notatum declined significantly when planted in diesel-oil contaminated soils. The presence of diesel fuel did not affect the growth of B. brizantha, which was highly tolerant to this pollutant. Bacterial growth was significant (p < 0.05 and the increase was directly proportional to the diesel dose. Bacteria growth in diesel-contaminated soils was stimulated up to 5-fold by the presence of grasses, demonstrating the positive interactions between rhizosphere and hydrocarbon-degrading bacteria in the remediation of diesel-contaminated soils.

Análise energética em sistema de produção de suínos com aproveitamento dos desejos como biofertilizante em pastagem Energy analysis in a swine production system with use of manure as biofertilizer in pasture

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Cássio V. Souza

2009-01-01

Full Text Available O objetivo deste trabalho foi estimar a quantidade de energia para a produção de suínos, em ciclo completo, e o balanço energético do sistema com reaproveitamento dos resíduos gerados como biofertilizante, em área de pastagem, utilizando dados médios de cinco ciclos, em granja comercial no município de Diamantina - MG. Quantificou-se o coeficiente energético de cada componente envolvido no processo produtivo de suínos terminados, tratamento dos resíduos e produção de pastagem de Brachiaria decumbens, nas formas de ração, trabalho humano, energia elétrica, máquinas e equipamentos, combustíveis e lubrificantes, instalações, produção de suínos vivos e produção de Brachiaria decumbens. A quantidade média de energia para produzir 1 kg de suíno vivo foi de 53,35 MJ. De toda energia empregada no sistema, 76,03% (1.067.106,07 MJ referem-se às entradas e 23,97% (331.400 MJ às saídas, resultando em coeficiente de eficiência energética de 0,31. A energia transformada em suínos para abate correspondeu a 55,58% (184.200 MJ das saídas, ao passo que a pastagem de Brachiaria decumbens assumiu o valor de 44,42% (147.200 MJ.This work objective was to esteem the amount of energy employed in a complete cycle swine production and the energy balance of the system with utilization of the generated manure as biofertilizer in pasture area, by using five cycles' average data, in a commercial farm in Diamantina municipal district - MG Brazil. The energy coefficient of each involved component was quantified in the productive process of finished swine, residues treatment and Brachiaria decumbens pasture production, in the form of ration, human labor, electric power, machines and equipments, fuel and lubricants, buildings, finished swine production and Brachiaria decumbens production. The average quantity of energy to produce 1 kg of alive swine was of 53.35 MJ. Of total employed energy in the system 76.03% (1,067,106.07 MJ refers to the

Evaluation of interspecific hybrids and cultivars of Brachiaria spp. submitted to sourcers and levels of nitrogen fertilization

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Márcia Atauri Cardelli Lucena

2012-12-01

Full Text Available The management of nitrogen supply (N is a very important issue concerned to plant growth and the environment healthy. For farmers, to know how much N the plant requires enables the application of appropriate amounts of nitrogen fertilizer, maximizing the use of this material. The availability of N has been identified as one of the main limiting factors, but also a management tool in the production of grasses. The nitrogen in the soil either, as a constituent of organic matter or in the mineral form (ammonium and nitrate, has a limited supply and can be depleted rapidly in a few crops. The aim of this study was to evaluate the effects of sources and nitrogen levels in four genotypes of Brachiaria (Brachiaria brizantha cv. Marandu, Brachiaria brizantha cv. Piata and two interspecific hybrids of Brachiaria spp on the total and the leaf dry matter production, leaf percentage and leaf: stem ratio. The soil was an Psament-Entisol, coming from a pasture of Brachiaria decumbens with low organic matter content. The experiment was conducted in greenhouse, in Nova Odessa, Sao Paulo, from October 2009 to April 2010. The experimental design was in randomized complete blocks and the treatments were arranged in a factorial 4 x 2 x 4, four genotypes of Brachiaria , two N sources (urea and ammonium nitrate and four nitrogen rates (0, 75, 150 or 225 mg dm-3 with five replicates, totaling 160 pots with a capacity of 3.34 dm3 of soil. Two cuts were performed in the plants. After the second cut a soil sample was collected from each experimental unit. Two evaluations were performed on plants. The first one 52 days after sowing, and the second 56 days after the first cut. Data were analyzed by the mixed procedure of SAS V. 9.2; average qualitative factors were compared by Tukey test at 5% probability. The degrees of freedom related to N rates (quantitative factor were decomposed into orthogonal polynomials; to obtain the best equation fits the data. The variables

Cacilda Borges Do Valle

Indian Academy of Sciences (India)

Home; Journals; Journal of Genetics. Cacilda Borges Do Valle. Articles written in Journal of Genetics. Volume 83 Issue 3 December 2004 pp 279-283 Research Note. Abnormal pollen mitoses (PM I and PM II) in an interspecific hybrid of Brachiaria ruziziensis and Brachiaria decumbens (Gramineae) · Andréa Beatriz ...

Energy analysis in a swine production system with use of manure as bio fertilizer in pasture; Analise energetica em sistema de producao de suinos com aproveitamento dos dejetos como biofertilizante em pastagem

Energy Technology Data Exchange (ETDEWEB)

Souza, Cassio V. [Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Diamantina, MG (Brazil)], email: agro.cassio@hotmail.com; Campos, Alessandro T. [Universidade Federal de Lavras (DEG/UFLA), MG (Brazil). Dept. de Engenharia], email: campos@deg.ufla.br; Bueno, Osmar C [Universidade Estadual Paulista (FCA/UNESP), Botucatu, SP (Brazil). Fac. de Ciencias Agronomicas; Silva, Enilson B [Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Diamantina, MG (Brazil). Dept. de Agronomia

2009-07-01

This work objective was to esteem the amount of energy employed in a complete cycle swine production and the energy balance of the system with utilization of the generated manure as bio fertilizer in pasture area, by using five cycles' average data, in a commercial farm in Diamantina municipal district - MG Brazil. The energy coefficient of each involved component was quantified in the productive process of finished swine, residues treatment and Brachiaria decumbens pasture production, in the form of ration, human labor, electric power, machines and equipment, fuel and lubricants, buildings, finished swine production and Brachiaria decumbens production. The average quantity of energy to produce 1 kg of alive swine was of 53.35 MJ. Of total employed energy in the system 76.03% (1,067,106.07 MJ) refers to the inputs and 23.97% (331,400 MJ) refers to the outputs, resulting in an energy efficiency coefficient of 0.31. The energy converted in swine for abate corresponded to 55.58% (184,200 MJ) of the outputs, while the pasture of Brachiaria decumbens reached a value of 44.42% (147,200 MJ). (author)

Atributos físicos e químicos de um latossolo vermelho-amarelo sob pastagens com diferentes históricos de uso Physical and chemical properties of an oxisol cultivated under pastures with distinct use history

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Iara Terezinha Pignataro Netto

2009-10-01

Full Text Available O uso sustentável dos sistemas de pastagens depende, principalmente, de um manejo que possa promover a qualidade do solo. O objetivo deste estudo foi avaliar as alterações nos atributos físicos e químicos do solo sob quatro pastagens, formadas com as espécies Andropogon gayanus, Brachiaria decumbens e Brachiaria brizantha cv. marandu, com diferentes históricos de uso, empregando como referência o Cerrado nativo. O solo foi avaliado pela quantificação dos seguintes atributos: capacidade de troca de cátions, matéria orgânica, densidade do solo, porosidade total e resistência mecânica à penetração. A capacidade de troca de cátions e o teor de matéria orgânica mostraram-se pouco afetados pelo manejo e pelo tempo de uso. A densidade do solo, a porosidade total e a resistência mecânica à penetração foram bastante afetadas, tendo grande influência na redução da qualidade do solo. Quantidade grande de animais, uso de máquinas e implementos, e cobertura deficiente, ocasionada pelo manejo inadequado, foram os principais fatores que promoveram as alterações no solo. O índice de qualidade do solo mostrou uma sequência decrescente, 0,83, 0,62, 0,51 e 0,23, respectivamente, para as áreas sob Andropogon gayanus (AN, Andropogon gayanus (AV, Brachiaria brizantha (BN e Brachiaria decumbens (BV.The sustainable use of pasture systems depends mainly on a management that promotes soil quality. This study aimed to evaluate changes in the physical and chemical soil properties of four areas under pasture growing the species Andropogon gayanus, Brachiaria decumbens and Brachiaria brizantha, cv. marandu, with different usage histories, in comparison to the reference of the natural Cerrado. The soil was evaluated based on the following properties: cation exchange capacity, soil organic matter, bulk density, porosity and soil mechanical penetration resistance. The cation exchange capacity and soil organic matter content were little

Avaliação de gramíneas forrageiras na região sul de Minas Gerais Evaluation of forage grasses for the south region of Minas Gerais

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Milton de Andrade Botrel

1999-04-01

Full Text Available Foram conduzidos dois experimentos na região do sul de Minas Gerais para avaliar o potencial de gramíneas forrageiras. No experimento 1 foram avaliadas as seguintes espécies, consideradas de baixa exigência nutricional: Andropogon gayanus, Kunt; Brachiaria brizantha, Stapf; Brachiaria decumbens, Stapf; Brachiaria ruziziensis, Germain Evrard; Brachiaria humidicola (Rendle Schweickt e Melinis minutiflora, Beauv. No experimento 2 foram avaliadas as gramíneas consideradas de média e alta exigência nutricional, a saber: Setaria sphacelata (Schum. Moss; Hemarthria altissima (Poir. Stapf; Chloris gayana, Kunt; Cynodon nlemfuensis, Vanderyst var. nlemfuensis; Hyparrhenia rufa, (Ness Stapf. e as cultivares de Panicum maximum, Jacq.: Tobiatã, Green Panic e Makueni. O delineamento experimental foi de blocos ao acaso com três repetições. Os níveis de calagem e de adubação para estabelecimento e manutenção foram diferenciados para os dois experimentos. Cada espécie foi avaliada nos seguintes aspectos: produção de forragem e teor de proteína bruta no período da seca e das chuvas e cobertura vegetal do solo. As gramíneas do experimento 1 que se destacaram na maioria dos aspectos avaliados foram: B. brizantha, B. decumbens, A. gayanus enquanto que no experimento 2 as espécies que apresentaram maior potencial forrageiro foram: S. sphacelata, P. maximum cv. Tobiatã.experiments were undertaken in the South region of Minas Gerais State, Brazil, to evaluate the yield potential of forage grasses. In experiment 1, the following species, considered as having low nutritional requirements, were evaluated: Andropogon gayanus, Kunt; Brachiaria brizantha, Stapf; Brachiaria decumbens, Stapf; Brachiaria ruziziensis, Germain Evrard; Brachiaria humidicola (Rendle Schweickt and Melinis minutiflora, Beauv. In experiment 2, the species considered as having medium and high nutritional requirements, that is: Setaria sphacelata (Schum.; Hemarthria altissima

Purification and characterization of lignin peroxidases from Penicillium decumbens P6

Energy Technology Data Exchange (ETDEWEB)

Yang, J.S.; Yuan, H.L.; Wang, H.X.; Chen, W.X. [China Agricultural University, Beijing (China). College of Biological Science

2005-06-01

Peroxidases are essential enzymes in biodegradation of lignin and lignite which have been investigated intensively in the white-rot fungi. This is the first report of purification and characterization of lignin peroxidase from Penicillium sp. P6 as lignite degradation fungus. The results indicated that the lignin peroxidase of Penicillium decumbens P6 had physical and chemical properties and a N-terminal amino acid sequence different from the lignin peroxidases of white-rot fungi. The lignin peroxidase was isolated from a liquid culture of P. decumbens P6. This enzyme had a molecular weight of 46.3 KDa in SDS-PAGE and exhibited greater activity, temperature stability and wider pH range than those previously reported. The isolation procedure involved (NH{sub 4}){sub 2}SO{sub 4} precipitation, ion-exchange chromatography on DEAE-cellulose and CM-cellulose, gel filtration on Sephadex G-100, and non-denaturing, discontinuous polyacrylamide gel electrophoresis. The K{sub m} and V{sub max} values of this enzyme using veratryl alcohol as substrate were 0.565 mmol L{sup -1} and 0.088 mmol (mg protein){sup -1} min{sup -1} respectively. The optimum pH of P6 lignin peroxidase was 4.0, and 70.6% of the relative activity was remained at pH 9.0. The optimum temperature of the enzyme was 45{sup o}C.

Características morfogênicas e estruturais do capim-braquiária em pastagem adubada com nitrogênio avaliadas nas quatro estações do ano Morphogenetical and structural characteristics of the signalgrass in a nitrogen fertilized pasture evaluated over the seasons of the year

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Jailson Lara Fagundes

2006-02-01

Full Text Available Este experimento foi realizado com o objetivo de avaliar o efeito da adubação nitrogenada sobre as características morfogênicas e estruturais de Brachiaria decumbens sob pastejo. Os tratamentos consistiram da aplicação de quatro doses de nitrogênio (75, 150, 225 e 300 kg/ha.ano antes do início das avaliações experimentais, realizadas em 2002 durante as estações de verão, outono, inverno e primavera. Utilizou-se o delineamento em blocos completos casualizados, com duas repetições. A taxa de alongamento de folha, o comprimento final da folha, o índice de área foliar e as porcentagens de colmo e de lâmina foliar aumentaram linearmente, enquanto a porcentagem de material morto decresceu com a adubação nitrogenada da Brachiaria decumbens sob pastejo. Não foi constatado efeito da adubação nitrogenada sobre o número de folhas vivas, de folhas emergentes e de folhas totais e as taxas de alongamento do colmo e de senescência foliar. A taxa de alongamento de folha e de colmo, o número de folhas vivas, o comprimento final da folha, o índice de área foliar e a porcentagem de lâmina foliar e de colmo de Brachiaria decumbens variaram entre estações do ano, apresentando valores menores no inverno.This experiment was carried out to evaluate the effects of nitrogen fertilization upon the morphogenetical and structural characteristics of Brachiaria decumbens under grazing. Four nitrogen rates (75, 150, 225 and 300 kg/ha.yr were applied before the beginning of the experimental evaluations, which were performed during the Summer, Fall, Winter and Spring seasons. The randomized complete block design was used with two replications. Linear increases were observed for the leaf elongation rate, final leaf length, leaf area index, stem and leaf blade percentage. The percentage of dead material decreased with the nitrogen fertilization. On the other hand, N fertilization had no effect on the number of alive leaf, number of emerging leaves

Brachiaria sp yield and nutrient contents after nitrogen and sulphur fertilization

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Reges Heinrichs

2013-08-01

Full Text Available Among the production factors, adequate fertilization is an important tool to raise the productivity of pastoral systems and consequently increase the share of Brazil in the supply chain of primary agricultural products at the global level. The objective of this study was to evaluate the interaction of nitrogen and sulfur fertilization in BRACHIARIA DECUMBENS: Stapf. The experiment in pots with Dystrophic Oxisol was evaluated in a completely randomized design with four replications in a 5 x 3 factorial arrangement, involving five N doses (0, 100, 200, 400, and 800 mg dm-3 in the form of ammonium nitrate and three S doses (0, 20 and 80 mg dm-3 in the form of calcium sulfate, with a total of 15 treatments. In the treatments with low S dose, calcium was provided as calcium chloride, to ensure a homogeneous Ca supply in all treatments. The results showed that the tiller production and dry weight of green leaves and of stems + sheaths and total dry weight were favored by the combination of N and S fertilizer, while the proportion of dry leaves was reduced. Nitrogen fertilization raised the N contents in green leaves and stems + sheaths and reduced K contents in fresh and dry leaves. The response to S rates in the N content of green leaves was quadratic.

Improved cellulolytic efficacy in Penicilium decumbens via heterologous expression of Hypocrea jecorina endoglucanase II

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Qin Yuqi

2013-01-01

Full Text Available Hypocrea jecorina endoglucanase II (Hjegl2 was heterologously expressed in Penicillium decumbens (yielding strain Pd::Hjegl2. After induction in cellulose containing media, strain Pd::Hjeg2 displayed increased carboxymethylcellulase activity (CMCase, 5.77 IU/ml, representing a 21% increase and cellulose degradation determined with a filter paper assay (FPA, 0.40 IU/ml, 67% increase, as compared to the parent strain. In media supplemented with glucose (2%, Pd::Hjegl2, displayed 51.2-fold and 3-fold higher CMCase and FPA activities, respectively, as compared to the parent strain. No changes in the expression levels of the four main native cellulase genes of P. decumbens (Pdegl1, Pdegl2, Pdcbh1, and Pdcbh2 were noted between the transformant and wild-type strains. These data support the idea that Hjegl2 cleaves both internal and terminal glycosidic residues, in a relatively random and processive manner. In situ polyacrylamide gelactivity staining of extracts derived from wild-type and Pd::Hjegl2 revealed two additional active fractions in the latter strain; one with a molecular mass ~50-65 KDa and another ~80-116 kDa.

Seletividade de herbicidas aplicados em pós-emergência sobre capim-braquiária Selectivity of post-emergence herbicides applied on signalgrass and palisadegrass

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Dagoberto Martins

2007-12-01

Full Text Available O estudo foi conduzido com o objetivo de avaliar a seletividade de alguns herbicidas inibidores de ALS e FS II aplicados em pós-emergência em plantas de Brachiaria brizantha cv. Marandu e Brachiaria decumbens cv. Basilisk em condições de campo e seu efeito na qualidade das sementes. Os herbicidas testados (em g/ha foram: imazethapyr a 100; chlorimuronethyl a 15; nicosulfuron a 50; bentazon a 720; e atrazine a 3.000, além de uma testemunha, sem aplicação de herbicidas. Dois experimentos em campo foram instalados em delineamento em blocos casualizados com quatro repetições e os ensaios de laboratório em delineamento inteiramente casualizado, com 16 repetições. Todos os herbicidas testados tiveram algum efeito de fitointoxicação visual aos cultivares avaliados. O nicosulfuron foi o herbicida que visualmente proporcionou os níveis mais elevados de injúrias às plantas de B. decumbens e B. brizantha. A produção de MS de B. brizantha nos estádios iniciais de crescimento foi reduzida pelos herbicidas nicosulfuron e atrazine, enquanto, em B. decumbens, apenas o herbicida nicosulfuron ocasionou redução da produção de MS. A qualidade das sementes de ambos os cultivares foi afetada pelo nicosulfuron, que induziu a dormência em sementes de B. decumbens, reduziu a porcentagem de sementes normais e, assim como o atrazine, aumentou a porcentagem de sementes mortas.This work evaluated the herbicides selectivity acetolactate synthase inhibitors and photosynthetic II applied in post- emergency in palisadegrass (Brachiaria brizantha cv. Marandu and signalgrass (Brachiaria decumbens cv. Basilisk plants in field conditions and their effect in seed quality. Treatments tested in g ha-1 were: imazethapyr at 100, chlorimuron-ethyl at 15, nicosulfuron at 50, bentazon at 720, atrazine at 3.000, and control plot. Two field trials were set up on complete randomized block design with four replicates; laboratory studies were carried out in a complete

Upland rice yield as affected by Brachiaria coverage management

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Adriano S. Nascente

2015-01-01

Full Text Available An important point in no-tillage system is the time between cover crop glyphosate desiccation and rice sowing. This study aimed to verify the effect of Brachiaria ruziziensis management time before rice sowing on rice yield and its components. The experiment was conducted under greenhouse conditions and consisted of four types of B. ruziziensis management: with Brachiaria and with herbicide (WBWH, without Brachiaria shoots and with herbicide (NBWH, without Brachiaria shoots and without herbicide (NBNH, and with Brachiaria and without herbicide (WBNH, at four times: 30, 20, 10, and 0 days, preceding the rice sowing. The amount of B. ruziziensis dry matter increased as the management was done closer to the rice sowing date. The WBWH and WBNH managements (this one causes the lowest rice grain yield must be done 30 days before rice sowing; while NBWH management must be done ten or more days before rice sowing. On the other hand, NBNH management (this one favors the best rice grain yield can be done until rice sowing day. Despite some reduction in rice yield caused by the B. ruziziensis management, when it was done at the proper time the rice grain yield was similar to the control (without Brachiaria sowing and without herbicide application.

Massa seca e composição bromatológica de quatro espécies de braquiárias semeadas na linha ou a lanço, em consórcio com milho no sistema plantio direto na palha = Dry mass and chemical composition of four Brachiaria species sown in rows or spread, in intercrop with corn crop in no-tillage system

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Cristiano Magalhães Pariz

2010-04-01

Full Text Available Objetivou-se avaliar a produtividade de massa seca (MS e a composiçãobromatológica de quatro espécies de Brachiaria em diferentes formas de semeadura, exclusivamente ou em consórcio com a cultura do milho, sob sistema plantio direto na palha. O experimento foi conduzido no ano de 2006, na FEPE, pertencente à FE/Unesp - Campus de IlhaSolteira, localizada no município de Selvíria, Estado do Mato Grosso do Sul. O solo da área experimental foi classificado como Latossolo Vermelho distroférrico. O delineamento experimental foi o de blocos casualizados, em esquema fatorial 4 x 4, com cinco repetições. Ostratamentos constituíram-se de quatro espécies de Brachiaria (B. brizantha cv. Marandu, B. decumbens, B. ruziziensis e capim-mulato II semeadas em linha e a lanço, de forma exclusiva ou consorciada simultaneamente com a semeadura da cultura do milho. Avaliou-se a produtividade de massa seca e os teores de NDT, PB, FDN, FDA, hemicelulose, celulose, lignina e cinzas da forragem. O consórcio a lanço das forrageiras com a cultura do milho se mostrou viável porapresentar produtividade de massa seca semelhante às modalidades de semeadura exclusiva, inversamente o que ocorreu com o consórcio na linha da cultura do milho, a qual reduziu tal produtividade. A B. ruziziensis apresentou melhor composição bromatológica e os consórcioselevaram os teores de NDT e PB, bem como reduziram os componentes da parede celular.The objective of this research was to evaluate the dry mass yield and chemical composition of four Brachiaria species in different options for sowing, exclusively or in intercrop with corn crop, under a no-tillage system. The experiment was carried out during the growing seasons of 2006 at FEPE (FE/Unesp, Ilha Solteira Campus located in Selvíria, Mato Grosso do Sul State, Brazil. The soil of the experimental area was classified as distroferric Red Latosol (Oxisol. The experimental design was in randomized blocks, in a factorial

PRINCIPAIS PLANTAS DANINHAS QUE INFESTAM AS CULTURAS DE ALGODÃO, ARROZ, CAFÉ, MILHO, SOJA E PASTAGENS NO ESTADO DE GOIÁS MAIN WEEDS THAT INFEST COTTON, RICE, COFFEE, MAIZE, SOYBEAN, AND PASTURES IN THE GOIÁS STATE

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Márcia Regina Albertoni

2007-09-01

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No presente trabalho foi realizado o levantamento das plantas daninhas nas culturas de algodão, arroz, café, milho, soja e nas pastagens de Brachiaria decumbens, Hyparrhenia rufa, Panicum maximum e Brachiaria humidicola em 65 municípios de 12 microrregiões do Estado de Goiás, entre janeiro de 1980 e julho de 1981, num total de 275 observações para 59 espécies de plantas daninhas identificadas.

A survey was made of weeds found in cotton, rice, corn and soybean fields and coffee plantations, and also in pastures composed of the following grasses: Brachiaria decumbens, Hyparrhenia rufa, Panicum maximum and Brachiaria humidicola. The study was carried out between January 1980 and July 1981, in a total of sixty-five counties within twelve micro-regions in the State of Goiás. Fifty-nine of known species of weeds were identified in a total of two-hundred and seventy-nine observations.

Phytochemical and Biological Properties of Ajuga decumbens ...

African Journals Online (AJOL)

antibacterial, antiviral, cytotoxic, as well as insecticidal activities. Several ... Hence, it would be useful to review current literature for available pharmacological activities of the plant as well as ... All plants of A. decumbens have been utilized as.

Atributos morfológicos y fisiológicos de genotipos de Brachiaria en un suelo con bajo fósforo disponible y alta saturación de aluminio

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Sergio Mejía Kerguelen

2009-01-01

Full Text Available RESUMEN Se evaluaron en invernadero en un suelo de Matazul, Meta, Colombia durante 6 semanas, 2 genotipos de Brachiaria (uno mejor adaptado a bajo P, B. decumbens y otro menos adaptado, B. ruziziensis y 8 progenies del cruzamiento entre ellos ( mejores adaptados: H-7, H-40, H-28, H-58; menos adaptados: H-190, H-94, H-82, H-179. Los genotipos mejor adaptados presentaron mayor biomasa aérea, explicada por mayor área foliar, mayor absorción de P en el tallo y mayor volumen de raíz. Las características morfológicas de las raíces, principalmente longitud, peso seco y contenido de P, permiteron mejor adaptación a bajo P disponible en el suelo. El periodo de evaluación fue suficiente para observar diferencias entre progenies.

Effects of aquous and ethanolic extracts of vegetal species on seed germination of Brachiaria decumbens Stapf/ Ação de extratos aquoso e etanólico de espécies vegetais na germinação de sementes de Brachiaria decumbens Stapf

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Ricardo Augusto Gorne Viani

2002-05-01

Full Text Available The objective of this study was to evaluate the effects of aquous and ethanolic extracts of medicinal species on seed germination of B. decumbens. The experimental design was completely randomized with 19 treatments (9 aquous extracts, 9 ethanolic extracts and a check was deionized water with 4 replicates. The species and organs used to obtain the extracts were Baccharis trimera (shoot, Baccharis articulata (shoot, Canna denudata (leaves, Cymbopogom citratus (leaves, Eucalyptus citriodora (leaves, Lippia alba (leaves and branches, Momordica charantia (leaves, branches, flowers, fruits and seeds, Ocimum gratissimum (leaves, branches and flowers e Ruta graveolens (leaves and branches. The extracts were obtained by aquous and ethanolic infusions in 10% and 1% concentration respectively. The seeds were treated with extracts for one hour and after this time sowed in plastic boxes. They were maintained in germination chamber (BOD with 16 hours of dark/20ºC and 8 hours of light/35ºC. The evaluation were made at 7Th and 21st days after seeding (DAS. The extraction methods affected seed germination. The use of aquous extract showed greater germination percentage than the ethanolic one at 7Th and 21st days. The evaluated extracts did not affect the seeds’ germination.O objetivo do experimento foi avaliar o efeito dos extratos aquoso e etanólico de espécies medicinais sobre germinação de sementes de B. decumbens. O delineamento experimental foi inteiramente casualizado com 19 tratamentos (9 extratos aquosos, 9 extratos etanólicos e 1 testemunha com água deionizada com quatro repetições. As espécies e as partes das plantas utilizadas para a obtenção dos extratos foram Baccharis trimera (caule, Baccharis articulata (caule, Canna denudata (folhas, Cymbopogom citratus (folhas, Eucalyptus citriodora (folhas, Lippia alba (folhas e ramos, Momordica charantia (folhas, ramos, flores, frutos e sementes, Ocimum gratissimum (folhas, ramos e flores e

Oliveria decumbens essential oil: Chemical compositions and antimicrobial activity against the growth of some clinical and standard strains causing infection.

Science.gov (United States)

Alizadeh Behbahani, Behrooz; Tabatabaei Yazdi, Farideh; Vasiee, Alireza; Mortazavi, Seyed Ali

2018-01-01

Oliveria decumbens as a valuable medicinal plant is extensively used in traditional medicine. clinical and standard strains causing infection resistance to antimicrobial agents, is one of the important problems in medicine. The aim of this study was to investigate the antibacterial activities and phytochemical analysis of Oliveria decumbens essential oil on the growth of some clinical and standard strains causing infection (Pseudomonas aerogenes, Escherichia coli, Streptococcus pyogenes and Staphylococcus epidermidis). Oliveria decumbens essential oil composition was identified by gas chromatography/mass spectrometry. Phytochemical analysis (alkaloids, saponins, flavone and phenolic) essential oil of the Oliveria decumbens were appraised based on qualitative methods. Several methods (disk diffusion, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC)) were used to appraise the antibacterial activity of the Oliveria decumbens essential oil. Thymol (28.45%) was the major compound of Oliveria decumbens essential oil. The total phenolics content (TPC) of the essential oil positively correlated with antioxidant activity (AA). The TPC and AA of Oliveria decumbens essential oil was equal to 92.45 ± 0.70 μg GAE/mg and 164.45 ± 1.20 μg/ml, respectively. The MIC of Oliveria decumbens essential oil ranged from 1 to 8 mg/ml depending on the type of bacteria (clinical and standard strains). The MBC of Oliveria decumbens essential oil varied from 1 mg/ml to 16 mg/ml. The smallest inhibition zone diameter (IZD) on different Oliveria decumbens essential oil concentrations on P. aeruginosa. Results indicate that Oliveria decumbens essential oil can prove to be an important source of AA and antibacterial and may be used for the treatment of infection diseases. Copyright © 2017 Elsevier Ltd. All rights reserved.

Production and quality of Urochloa decumbens (stapf r.d. webster forage co-related to the physical and chemical properties of the soil

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Flávio Carlos Dalchiavon

Full Text Available ABSTRACT Frequently degraded pastureland characterized by low soil fertility and compacted surface is the basic environment of Brazilian livestock. The physical and chemical characterization of soil and its co-relationship with forage production are determining factors for performance of animals raised on pasture. The objective was to analyze the forage production of Urochloa decumbens grass correlated, linearly and spatially, with physical and chemical attributes of a savannah soil in Selvíria - MS, Brazil. A geostatistical web was introduced for the collection of soil and plant data, with 120 sampling sites within an area of 56.09 ha. The descriptive analysis of the data was undertaken and linear co-relationships, both simple and multiple, were established between plant and soil properties. Semivariograms were modeled and their respective krigings and cross-validations obtained, coupled to co-krigings (plant and soil. Production of dry matter and crude protein rates of U. decumbens may be estimated by regressions and the mechanical resistance to penetration and gravimetric humidity of the soil evaluated. Since organic matter rate and the gravimetric humidity of the soil are co-related spatially with the rate of crude protein of U. decumbens, they are the best factors to calculate or increase the forage crude protein rate.

Dinâmicas de trânsito e degradação da fibra em detergente neutro em bovinos alimentados com forragem tropical de baixa qualidade e compostos nitrogenados Transit and degradation dynamics of neutral detergent fiber in cattle fed low-quality tropical forage and nitrogenous compounds

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I. Lazzarini

2009-06-01

Full Text Available Avaliaram-se as dinâmicas de trânsito e degradação da fibra em detergente neutro (FDN em bovinos alimentados com forragem tropical de baixa qualidade e compostos nitrogenados. Foram utilizadas cinco novilhas Holandês x Zebu fistuladas no rúmen. A alimentação volumosa basal dos animais foi constituída por feno de capim-braquiária (Brachiaria decumbens Stapf., com 5,08% de proteína bruta (PB, com base na matéria seca (MS, fornecido ad libitum. Os cinco tratamentos avaliados foram definidos de acordo com o nível de suplementação proteica (0, 3, 5, 7 e 9 pontos percentuais acima do nível de PB da forragem. Como fonte de compostos nitrogenados, empregou-se mistura de ureia:sulfato de amônia:albumina (4,5:0,5:1,0. O experimento foi estruturado segundo delineamento em quadrado latino 5 x 5. Os níveis médios de PB nas dietas foram de 5,28; 8,08; 9,82; 11,87 e 13,63%, com base na MS. Verificou-se elevação linear (PRumen transit and degradation dynamics of neutral detergent fiber (NDF in cattle fed low-quality tropical forage and nitrogenous compounds were evaluated. Five crossbred heifers fitted with rumen cannulae were used. The animals were fed ad libitum with signal grass (Brachiaria decumbens Stapf. hay, which had crude protein (CP content of 5.08% in dry matter (DM. The five treatments were defined according to the level of CP in the diet (0, 3, 5, 7, and 9 percentile points above the CP level of the roughage. The supplement was a mixture of urea, ammonium sulfate, and albumin (4.5:0.5:1.0, respectively. The experiment was carried out according to a 5 x 5 Latin square design. The average CP levels in the diets were: 5.28, 8.08, 9.82, 11.87, and 13.63% in DM basis. The potentially degradable fraction of NDF was linearly increased (P<0.05 by CP levels in diet until 8.62% CP. From this point, there was stabilization of estimates (47.92% of NDF. The degradation rate of potentially degradable NDF showed a quadratic response (P<0

Patogenicidade de Helminthosporium oryzae a algumas espécies de gramíneas Pathogenicity of Helminthosporium oryzae against some grass species

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V.H. Artigiani Filho

1995-04-01

Full Text Available O fungo Helminthosporium oryzae é um patógeno do arroz. Devido a sua variabilidade patogênica, foi investigada a possibilidade deste fungo infectar outras gramíneas. Através de inoculação artificial, ficou demonstrada a capacidade deste patógeno provocar infecção em aveia, cana, centeio, sorgo, trigo, Brachiaria decumbens e Panicum maximum. Assim, estas espécies vegetais podem ser consideradas potenciais hospedeiros do fungo na natureza.Helminthosporium oryzae is a rice pathogen. Due to its variability in pathogenicity, the possibility of this fungus Infecting other grasses was investigated. The capacity of this pathogen was demonstrated to be able to infect oat, sugar-cane, rye, sorghum, wheat, Brachiaria decumbens and Panicum maximum through artificial inoculations. Therefore, those plant species can be considered potencial hosts for the fungus in nature.

Recovery of degraded pasture in Rondônia: macronutrients and productivity of brachiaria brizantha Recuperação de pastagem degradada em Rondônia: macronutrientes e produtividade da brachiaria brizantha

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Norberto Cornejo Noronha

2010-10-01

Full Text Available Pasture is the main form of land use in Amazonia. Over time the pasture grass loses vigor and yields decrease, indicating a certain degree of degeneration. The main causes of degradation are lack of pasture maintenance and subsequent weed infestation, the choice of regionally unsuitable forage species and excessive grazing. The main purpose of this study was to evaluate the impact of different recovery managements on soil chemical properties and grass yield of a degraded pasture in Rondônia. For this purpose, an experiment was installed in October 2001, consisting of five treatments: C = control; HA = harrowing + NPK + micronutrients; HE = Herbicide + NK + micronutrients; R = No-tillage rice + NPK + micronutrients; and S = No-tillage soybean + PK + micronutrients. The following N, P and K sources were used: ammonium sulfate for N, calcined phosphate for P and potassium chloride for K. The experiment was arranged in a randomized block design with four replications. The shoot dry matter yield of the grass was analyzed as of the 35th month of experimentation, in a dry and a rainy period. Phosphorus fertilization resulted in significant increases in Ca2+ and Mg2+ and increasing trend of P in the topsoil in the initial months of the experiment in treatments HA and S and increases in Ca2+ and P (trend in the treatment R. The cumulative production of Brachiaria brizantha, from Sep/2004 to Mar/2005, was 30,025, 28,267 and 27,735 kg ha-1 shoot dry matter in the treatments HA, R and S, respectively. These values differed significantly from treatments C and HE, with 17,040 and 17,057 kg ha-1, respectively. It was concluded that phosphorus fertilization associated to pasture reform was effective to raise the dry matter yield of Brachiaria brizantha. Rice or soybean under no-tillage is recommended as a practice of pasture recovery, due to the residual effect of fertilization.As pastagens consistem no principal uso da terra na Amazônia. Com o tempo de

Massa seca e composição bromatológica de quatro espécies de braquiárias semeadas na linha ou a lanço, em consórcio com milho no sistema plantio direto na palha - doi: 10.4025/actascianimsci.v32i2.8498 Dry mass and chemical composition of four Brachiaria species sown in rows or spread, in intercrop with corn crop in no-tillage system - doi: 10.4025/actascianimsci.v32i2.8498

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Luiz Malcolm Mano de Mello

2010-07-01

Full Text Available Objetivou-se avaliar a produtividade de massa seca (MS e a composição bromatológica de quatro espécies de Brachiaria em diferentes formas de semeadura, exclusivamente ou em consórcio com a cultura do milho, sob sistema plantio direto na palha. O experimento foi conduzido no ano de 2006, na FEPE, pertencente à FE/Unesp - Campus de Ilha Solteira, localizada no município de Selvíria, Estado do Mato Grosso do Sul. O solo da área experimental foi classificado como Latossolo Vermelho distroférrico. O delineamento experimental foi o de blocos casualizados, em esquema fatorial 4 x 4, com cinco repetições. Os tratamentos constituíram-se de quatro espécies de Brachiaria (B. brizantha cv. Marandu, B. decumbens, B. ruziziensis e capim-mulato II semeadas em linha e a lanço, de forma exclusiva ou consorciada simultaneamente com a semeadura da cultura do milho. Avaliou-se a produtividade de massa seca e os teores de NDT, PB, FDN, FDA, hemicelulose, celulose, lignina e cinzas da forragem. O consórcio a lanço das forrageiras com a cultura do milho se mostrou viável por apresentar produtividade de massa seca semelhante às modalidades de semeadura exclusiva, inversamente o que ocorreu com o consórcio na linha da cultura do milho, a qual reduziu tal produtividade. A B. ruziziensis apresentou melhor composição bromatológica e os consórcios elevaram os teores de NDT e PB, bem como reduziram os componentes da parede celular.The objective of this research was to evaluate the dry mass yield and chemical composition of four Brachiaria species in different options for sowing, exclusively or in intercrop with corn crop, under a no-tillage system. The experiment was carried out during the growing seasons of 2006 at FEPE (FE/Unesp, Ilha Solteira Campus located in Selvíria, Mato Grosso do Sul State, Brazil. The soil of the experimental area was classified as distroferric Red Latosol (Oxisol. The experimental design was in randomized blocks, in a

Parâmetros da degradação protéica ruminal de diferentes alimentos e rações estimados por técnica in vitro Parameters of ruminal protein degradation of different feeds and diets estimated by an in vitro method

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R.P. Lana

2007-04-01

-elefante apresentou o menor nível de amônia e a de cepilho, o maior. As camas influenciaram o conteúdo de proteína solúvel e a DPB, que variaram de 9,0 a 14,5mg/dl e 39 a 63%, respectivamente, sem efeitos da monensina.Three experiments were carried out in order to study the parameters of ruminal protein degradation. In the first, isoproteic diets, constituted of elephant grass, ground corn and soybean meal, at five concentrate levels (0:100, 25:75, 50:50, 75:25 e 100:0, with or without monensin (5µM, were incubated in ruminal fluid of bovines. There was a decreasing linear effect of the concentrate level on ammonia concentration and degradability of crude protein, and cubic effect in soluble protein concentration, with the largest value in the diet with 25% concentrate. Monensin decreased degradability of crude protein and soluble protein concentration with no effect on ammonia production. In the second, five different roughages (corn and elephant grass silage - Pennisetum purpureum, Brachiaria haylage - Brachiaria decumbens, ammoniated Tifton 85 hay - Cynodon sp. e Tifton 85 hay. The were incubated Brachiaria haylage and the ammoniated Tifton 85 hay showed the greatest concentrations of ammonia (8.7 and 5.3mg/dl and soluble protein (5.4 and 7.0mg/dl, due to their higher crude protein content, followed by elephant grass silage and Tifton 85 hay. The degradability of crude protein ranged from 29.6 to 80.6% for Brachiaria haylage and Tifton 85 hay, and the degradability of dry matter ranged from 40.1 to 64.3% for elephant grass silage and Brachiaria haylage, respectively. The effective degradability of crude protein showed low values due to low degradation rate of the insoluble fraction. In the third, four different poultry litter (hulls coffee, shopped dry elephant grass, corn cobs and wood shavings were incubated, with or without monensin (5µM. No difference in ammonia concentration among the poultry litter samples, was observed in the absence of monensin. However, when

Chromosome numbers and meiotic analysis in the pre-breeding of ...

Indian Academy of Sciences (India)

2011-08-19

Aug 19, 2011 ... of Brachiaria decumbens (Poaceae). GLÉIA CRISTINA LAVERDE ... widely used grass forage worldwide because it adapts to acid soils, is easy to man- ... individual plants growing in the field, fixed in a mixture of ethanol 95% ...

Correlações entre características estruturais e valor nutritivo de perfilhos em pastos de capim-braquiária diferidos e adubados com nitrogênio Correlations among structural characteristics and nutritional value of tillers on deferred and nitrogen-fertilized signalgrass pastures

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Virgilio Mesquita Gomes

2010-09-01

Full Text Available Perfilhos de Brachiaria decumbens cv. Basilisk foram amostrados em pastos diferidos e adubados com nitrogênio (0, 40, 80 e 120kg/ha de N com o objetivo de avaliar correlações entre suas características estruturais, morfológicas e de valor nutritivo. Foi adotado o delineamento em blocos ao acaso, com três repetições. Não foi observada correlação entre número e peso de perfilhos. Porém, houve correlação positiva do peso do perfilho com comprimento do colmo, número de folha morta e percentual de colmo verde e negativa com número de folhas verdes e percentual de folha verde. As correlações entre número de perfilhos foram positivas com os percentuais de proteína bruta, fibra em detergente neutro potencialmente digestível e matéria seca potencialmente digestível e negativa para fibra em detergente neutro e fibra em detergente neutro indigestível. De outra forma, o peso dos perfilhos apresentou correlação positiva com os teores de fibra em detergente neutro e fibra em detergente neutro indigestível e associação negativa com o percentual de matéria seca potencialmente digestível. O negativa com número de folhas verdes apresentou correlações positivas com os teores de proteína bruta, fibra em detergente neutro potencialmente digestível e matéria seca potencialmente digestível, bem como correlações negativas com os percentuais de fibra em detergente neutro e fibra em detergente neutro indigestível. A composição morfológica e o valor nutritivo de perfilhos de Brachiaria decumbens cv. Basilisk foram determinados por suas características estruturais. Em pastos diferidos de Brachiaria decumbens cv. Basilisk ocorreu compensação entre tamanho e valor nutritivo de perfilhos.Brachiaria decumbens cv. Basilisk tillers were sampled on deferred and nitrogen-fertilized pastures (0, 40, 80 and 120kg/ha of N, in order to evaluate correlations among its structural characteristics, morphological composition and nutritional

INTEGRATION OF MECHANICAL AND CULTURAL CONTROL TREATMENTS TO MANAGE INVASIVE SHRUB Chromolaena odorata AND OTHER WEEDS UNDER DROUGHT CONDITIONS IN PASTURE AREA

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M. Rusdy

2013-03-01

Full Text Available A field experiment was conducted on Chromolaena odorata dominated pasture with the objectives of evaluating efficacy of integrated of mechanical and cultural control on weed suppression and determining botanical composition of plant species after treatment started. The treatments were, T1 slashing of Chromolaena every month, T2 digging up of Chromolanea, and exposed to dry (mulching, T3 digging up of Chromolaena followed by burning, T4 digging up of Chromolaena followed by burning and sowing with Centrosema pubescens and T5 digging up of Chromolaena followed by burning and planting with Brachiaria decumbens. Results of experiment showed that under drought conditions, digging up Chromolaena was very effective in suppressing regrowth of Chromolaena but it was not effective to other weeds. Among treatments, digging out of Chromolaena followed by burning and planting with Brachiaria decumbens was the most effective and slashing of Chromolaena every month was the least effective in suppressing weeds. Botanical composition was shifted with treatments. Stachytarpheta jamaicensis and Chromolaena were the dominant species in monthly slashed Chromolaena plots, Stachytarpheta and Calopogonium muconoides were the dominant species in mulched plots while Mimosa pudica, Brachiaria and Centrosema were the dominant species in burnt plots.

INTEGRATION OF MECHANICAL AND CULTURAL CONTROL TREATMENTS TO MANAGE INVASIVE SHRUB Chromolaena odorata AND OTHER WEEDS UNDER DROUGHT CONDITIONS IN PASTURE AREA

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M. Rusdy

2014-10-01

Full Text Available A field experiment was conducted on Chromolaena odorata dominated pasture with the objectivesof evaluating efficacy of integrated of mechanical and cultural control on weed suppression anddetermining botanical composition of plant species after treatment started. The treatments were, T1slashing of Chromolaena every month, T2 digging up of Chromolanea, and exposed to dry (mulching,T3 digging up of Chromolaena followed by burning, T4 digging up of Chromolaena followed byburning and sowing with Centrosema pubescens and T5 digging up of Chromolaena followed byburning and planting with Brachiaria decumbens. Results of experiment showed that under droughtconditions, digging up Chromolaena was very effective in suppressing regrowth of Chromolaena but itwas not effective to other weeds. Among treatments, digging out of Chromolaena followed by burningand planting with Brachiaria decumbens was the most effective and slashing of Chromolaena everymonth was the least effective in suppressing weeds. Botanical composition was shifted with treatments.Stachytarpheta jamaicensis and Chromolaena were the dominant species in monthly slashedChromolaena plots, Stachytarpheta and Calopogonium muconoides were the dominant species inmulched plots while Mimosa pudica, Brachiaria and Centrosema were the dominant species in burntplots.

Allelopathic effect of Raphanus sativus on Urochloa decumbens and Lactuca sativa = Efeito alelopático de Raphanus sativus em Urochloa decumbens e Lactuca sativa

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Rafael Navas

2016-10-01

Full Text Available The aim of this study was to evaluate the allelopathic potential of an extract from the leaves and roots of Raphanus sativus, on the species Urochloa decumbens and Lactuca sativa L. To obtain the extract, the leaves and roots of R. sativus were used separately, crushed at a proportion of 200 g of leaves to 1 L of water to give a crude aqueous extract (100%. Dilutions of 60%, 40% and 20%, and the control were produced from this extract. Seeds of U. decumbens and L. sativa were evenly distributed over two sheets of germitest paper, with four replications of 40 seeds each. Germination was evaluated at 7 and 14 days after sowing, together with the germination speed index (GSI, length of the shoots and roots, and dry weight. The design was completely randomised, and the values submitted to analysis of variance by F-test and regression analysis. The leaf extract gave a reduction in the germination of L. sativa at all tested doses. With application of the root extract, an increase was seen in germination, in the GSI and length of the radicle in U. decumbens at doses of from 40%. Moreover, with application of the leaf extract, the length of the shoot and radicle were also greater, irrespective of the dose applied. There was no effect from the treatments on the dry mass of the species. = Objetivou-se com este trabalho avaliar o potencial alelopático de extrato de folhas e raízes de Raphanus sativus, nas espécies Urochloa decumbens e Lactuca sativa L. Para obtenção do extrato, foram utilizadas separadamente folhas e raízes de R. sativus, trituradas na proporção de 200 g de folhas para 1 L de água, resultando no extrato aquoso bruto (100%. A partir desse extrato, foram realizadas as diluições de 60%, 40% e 20% e testemunha. Sementes de U. decumbens e L. sativa foram distribuídas uniformemente sobre duas folhas de papel germitest, com quatro repetições, com 40 sementes cada. As avaliações de germinação foram realizadas aos 7 e aos 14 dias

CARACTERÍSTICAS ESTRUTURAIS DE PERFILHOS VEGETATIVOS E REPRODUTIVOS EM PASTOS DIFERIDOS DE CAPIM-BRAQUIÁRIA

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Manoel Eduardo Rozalino Santos

2010-10-01

Full Text Available The aim of this work was to compare the structural characteristics of vegetative and reproductive tillers on Brachiaria decumbens cv. Basilisk pastures diferred for 73, 95 and 116 days. Randomized block design in a split plot scheme with three replications was used. The stockpiling period did not influence (P>0.10 the number of vegetative tillers (VT but increased (P0.10 by the deferring period. The RT revealed (P<0.05 a higher pseudostem length, higher number of dead leaves (NDL and lower NLL when compared to VT. RT showed (P<0.05 higher percentages of stem and dead leaf as well as a lower percentage of living leaf (P<0.05 than VT. VT showed a better morphological composition than RT. The deferring period alters the structural characteristics and worsens the morphological composition of tillers on deferred Brachiaria decumbens cv. Basilisk pastures.KEYWORDS:

Caracterização dos perfilhos em pastos de capim-braquiária diferidos e adubados com nitrogênio Tiller characteristics in nitrogen fertilized and deferred signalgrass pastures

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Manoel Eduardo Rozalino Santos

2009-04-01

Full Text Available Este trabalho foi conduzido com o objetivo de avaliar o perfilhamento e as características estruturais de perfilhos em pastos de Brachiaria decumbens cv. Basilisk sob três períodos de diferimento da pastagem (73, 95 e 116 dias e quatro doses de nitrogênio (N (0, 40, 80 e 120 kg/ha. O delineamento experimental foi em blocos casualizados, com três repetições, em esquema de parcelas subdivididas. O número de perfilhos vegetativos (PV reduziu com o aumento do período de diferimento. Houve interação entre período de diferimento e dose de N para a densidade populacional de PV. O maior período de diferimento elevou o número de perfilhos reprodutivos (PR nos pastos de capim-braquiária, mas não houve efeito da dose de N sobre o número de perfilhos reprodutivos. O número de perfilhos mortos não foi influenciado pelos fatores estudados. Tanto o período de diferimento quanto a adubação nitrogenada aumentaram o peso de todas as categorias de perfilhos de capim-braquiária. As características estruturais dos perfilhos presentes nos pastos diferidos foram alteradas pelo período de diferimento e pela dose de nitrogênio. A redução do período de diferimento e a adubação nitrogenada são estratégias de manejo adequadas para aumentar o número de perfilhos vegetativos em pastos de Brachiaria decumbens cv. Basilisk.This work aimed to evaluate the tilling and tiller structural characteristics on Brachiaria decumbens cv. Basilisk pasture fertilized with nitrogen (N under different deferring periods. The treatments had 73, 95 and 116-day deferring periods, and 0, 40, 80 and 120 kg/ha N doses. A randomized block design with three replicates and subdivided plots was used. The number of vegetative tillers (VT reduced as the deferring period increased. Interaction between the deferring period and N doses on the VT population density was verified. The longest deferring period increased the number of reproductive tillers (RT on the B. decumbens

Uso de lodo de esgoto na reestruturação de solo degradado Use of sewage sludge to restructure a degraded oxisol

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Fabiana da Silva de Campos

2008-08-01

degradation. In this sense, this study aimed to investigate the influence of sewage sludge on the recovery of physical properties of a degraded Oxisol, cultivated for 2.5 years with eucalyptus (Eucalyptus citriodora Hook and Brachiaria grass (Brachiaria decumbens, in Selvíria, MS, Brazil. Six treatments were evaluated in an experiment in a randomized block design with four replications: (1 Savannah; (2 exposed soil without treatment for recovery; (3 soil under eucalyptus and pasture (without application of sewage sludge or mineral fertilization; (4 soil under eucalyptus and pasture with mineral fertilization; (5 soil under eucalyptus and pasture with application of 30 Mg ha-1 sewage sludge, and (6 soil under eucalyptus and pasture with application of 60 Mg ha-1 sewage sludge. In the soil layers 0.00-0.05; 0.05-0.10; 0.10-0.20 and of 0.20-0.30 m, the following physical properties were studied: macroporosity; microporosity; soil porosity, and bulk density. Green and dry mass of pasture and height and DBH of eucalyptus were evaluated. It was concluded that the studied soil is a recovery process. The treatments with sludge application were more effective because of their influence on the soil physical properties, besides resulting in higher green and dry mass yield in brachiaria and increased growth of eucalyptus trees. The best indicators of soil recovery were plant development, soil bulk density, total porosity, and macroporosity.

Recovery of soil physical properties by green manure, liming, gypsum and pasture and spontaneous native species¹

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Carolina dos Santos Batista Bonini

2011-08-01

Full Text Available Inadequate usage can degrade natural resources, particularly soils. More attention has been paid to practices aiming at the recovery of degraded soils in the last years, e.g, the use of organic fertilizers, liming and introduction of species adapted to adverse conditions. The purpose of this study was therefore to investigate the recovery of physical properties of a Red Latosol (Oxisol degraded by the construction of a hydroelectric power station. In the study area, a soil layer about 8m thick had been withdrawn by heavy machines leading not only to soil compaction, but resulting in high-degree degradation. The experiment was arranged in a completely randomized design with nine treatments and four replications. The treatments consisted of: 1- soil mobilization by tilling (to ensure the effect of mechanical mobilization in all treatments without planting, but growth of spontaneous vegetation; 2- Black velvet bean (Stizolobium aterrimum Piper & Tracy; 3- Pigeonpea (Cajanus cajan (L. DC; 4- Liming + black velvet bean; 5-Liming + pigeonpea until 1994, when replaced by jack bean (Canavalia ensiformis; 6- Liming + gypsum + black velvet bean; 7- Liming + gypsum + pigeonpea until 1994, when replaced by jack bean; and two controls as reference: 8- Native Cerrado vegetation and 9- bare soil (no tilling and no planting, left under natural conditions and in this situation, without spontaneous vegetation. In treatments 1 through 7, the soil was tilled. Treatments were installed in 1992 and left unmanaged for seven years, until brachiaria (Brachiaria decumbens was planted in all plots in 1999. Seventeen years after implantation, the properties soil macroporosity, microporosity, total porosity, bulk density and aggregate stability were assessed in the previously described treatments in the soil layers 0.00-0.10; 0.10-0.20 and 0.20-0.40 m, and soil Penetration Resistance and soil moisture in 0.00-0.15 and 0.15-0.30 m. The plants were evaluated for: brachiaria

Forage accumulation in brachiaria grass under continuous grazing with single or variable height during the seasons of the year

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Manoel Eduardo Rozalino Santos

2013-05-01

Full Text Available The objective of this study was to evaluate grazing management strategies of Brachiaria decumbens cv. Basilisk managed with different heights under continuous grazing with cattle. Two grazing management strategies were evaluated: maintenance of pasture with an average height of 25 cm throughout the experimental period and maintenance of pasture on the average of 15 cm in height during winter, up to 25 cm from the beginning of spring. The split-plot scheme and the randomized block design with four replications were adopted. The grazing management strategies corresponded to the primary factor, while the seasons (winter, spring and summer corresponded to secondary factor. The reduction of the average sward height to 15 cm in the winter resulted, when compared with pasture maintained at 25 cm, in overall higher growth rates (95 kg/ha.day DM and leaf blade (66.1 kg/ha.day DM, as well as higher rates of total accumulation (81.5 kg/ha.day DM and leaf blade (52.6 kg/ha.day DM. The accumulated forage production (from winter to summer was higher in the pasture lowered to 15 cm in winter (25.6 t/ha DM compared with that managed with an average height of 25 cm (22.2 t/ha DM. Regarding the seasons of the year, in the winter, there were lower rates of overall growth (6.4 kg/ha.day DM, leaf blade (5.6 kg/ha.day DM and pseudostem (0.8 kg/ha.day DM, and also lower total (-6.6 kg/ha.day DM and leaf blade (-7.5 kg/ha.day DM accumulation rates. In the spring there was a higher rate of leaf senescence (22.4 kg/ha.day DM. The accumulation of forage is incremented when the pasture of B. decumbens is lowered to 15 cm during the winter, and in the spring and summer, its average height is increased to 25 cm.

Avaliação das características estruturais do capim-braquiária em pastagens adubadas com nitrogênio nas quatro estações do ano

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Fagundes Jailson Lara

2006-01-01

Full Text Available Este experimento foi realizado com o objetivo de avaliar o efeito da adubação nitrogenada sobre a demografia de perfilhos e a biomassa forrageira em pastagens de Brachiaria decumbens cv. Basilisk submetidas à mesma intensidade de pastejo. Os tratamentos consistiram da aplicação de quatro doses de nitrogênio (75, 150, 225 e 300 kg/ha.ano antes do período das avaliações experimentais, realizadas durante as estações verão, outono, inverno e primavera de 2002. O delineamento foi em blocos completos, casualizados com duas repetições. A demografia populacional de perfilhos e a biomassa forrageira de B. decumbens variaram com as estações do ano e com as doses de nitrogênio. A densidade populacional de perfilhos vegetativos e vivos aumentou linearmente, enquanto a de perfilhos mortos decresceu linearmente com as doses de N. A biomassa forrageira também aumentou linearmente, ao passo que a densidade populacional de perfilhos reprodutivos não foi influenciada pela adubação nitrogenada. A densidade populacional de perfilhos vivos, vegetativos e reprodutivos e a biomassa de folhas, de colmo e de material verde de Brachiaria decumbens variaram entre as estações do ano, apresentando valores menores no inverno.

Evaluación de pasturas de Brachiaria decumbens solas o asociadas con Centrosema acutifolium con ganado de doble propósito: I. Evaluación de la disponibilidad, composición botánica, frecuencia y calidad forrajera

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Ramírez Náder Luis Miguel

1991-12-01

Full Text Available

At the Miravalle farm, located at Florida, Cauca Valley, at southwest of Colombia (3° 20' N, 76° 14'0 and 1150 m of altitude, it was done this experiment an area representative of INCEPTISOL soils acids (pH 5.8-6.3. Mean temperature 25°C and mean anual rainfall 1339 mm. Were used 4 fields of 4 ha each one; two of them had B. decumbens alone and the other two B. decumbens plus C. acutifolium CIAT 5568. Each pasture was grazed in alternating way using 21 days of occupation and 21 days of rest. There was a fixed animal charge of 1.5 animal units per ha. The sampling method was the BOTANAL-2. The green dry matter coming from the grass (GDMG, and from legume (GDML; and the total dry matter (TMD, were always higher for the associate pasture in relation to the alone pasture all over the experiment, with means of 4.627 vs. 2.296; 689 vs. 45  and 6.476 vs. 3.698 kg/ha, for GDMG, GDML and TDM respectively. In contrast, green dry matter coming from the weeds (GDMW and the inert plant material (GDMI were superior for the alone pasture with means of 345 vs. 265 and 798 vs. 631 kg/ha for GDMW and GDMI, respectively. The botanical composition had more stable proportions on the associate pasture than on the alone pasture; having higher percentages in grass, 72 vs. 65% and legume, 11 vs. 1% and lower percentages in weeds, 4 vs. 9% and inert planta material, 9 vs. 22%, respectively. The frequency of presence of species showed similar values between the two pastures, for the grass frequency, 96 vs. 98%, and for the other species, 11 vs. 9%; but higher for the associated pasture at the legume frequency, 81 vs. 12%, in relation to the alone pasture. Also for the associate pasture were obtained lower values for weeds frequency, 47 vs. 52%, and inert plant material, 84 vs. 97%, respectively. Uncover soils, for the associate pasture was lower, 5% than the alone pasture, 16%. The percentage of protein was higher in the legume C. acutifolium 15.3%. For B

Effect of sulfur levels on four tropical grasses in cerrado soils of mato grosso do sul, Brazil

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Carlos Casagrande, J.; Correa De Souza, O.

1982-01-01

A greenhouse experiment was conducted to evaluate responses of four tropical grasses, Melinis minutiflora cv. Cabelo de Negro Hyparrhenia rufa, Brachiaria decumbens australian type and Setaria anceps cv. kazungula to five levels of sulfur (0, 15, 30, 45 and 60 kg/ha) in two cerrado Oxisols and one Entisol. Cuttings were done at 50, 95 and 150 days after plant exposure. Besides dry matter production, visible symptoms of sulfur deficiency were observed. Greater responses were associated with sulfur rates up to 30 kg/ha. Molasses grass and brachiaria were the most responsive species.

Rendimiento y calidad fisiológica de la semilla de Brachiaria spp. en los llanos colombianos

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Sánchez O. M.

1996-12-01

Full Text Available

186 accessions of 9 species of Brachiaria were established in a design of fringes divided on 2 repetitions. In the third year seeds were evaluated to test their potencial under 2 different fertility levels: a One recommended in order to establish pastures; b Other in order to establish a system composed rice-pasture. The yield and the seed weight unit did not present significant differences (P<0.05 in the utilization of one or another level of fertility. The viability test at 11 and 14 mpc showed that B. humidicola had the higher viability, while B. brizantha have the lower value at 11 mpc and B. dictyoneura at 14 mpc. The germination and dormancy tests evaluated the effect of 2 treatments: 1 Water and 2 Scarification seeds with sulphuric acid or with potassium nitrate for the case of B. humidicola. B. humidicola had the best germination at 11mpc, while B. dictyoneura reached the highest germination percentage at 14 mpc.

The effect of ensiling and haymaking on the concentrations of steroidal saponin in two Brachiaria grass species

Science.gov (United States)

Brachiaria (signalgrass) is now the most widely used tropical grass genus in Central and South America. However, Brachiaria spp. can cause hepatogenous photosensitization in livestock. Steroidal saponins, specifically protodioscin, present in Brachiaria spp. may be responsible for liver injury and s...

Soybean in different forms of processing in the feeding of crossbred cows on brachiaria grass pastures

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Vinícius Raimundi Andrade

2015-02-01

Full Text Available The objective was to evaluate intake and digestibility of nutrients, as well as milk production and composition of the milk from F1 Holstein × Gyr cows kept on pasture, supplemented with sugarcane and concentrate (28% CP. Five cows with 150±14 lactation days and average milk production of 7.1±2.1 kg/day were distributed in a 5 × 5 Latin square design. The treatments were: soybean meal-based concentrate; soy bean-based concentrate; ground soybean-based concentrate; roasted soybean-based concentrate; and ground, roasted soybean-based concentrate. Dry matter (DM, organic matter, crude protein (CP, neutral detergent fiber (NDF, total carbohydrates and total digestible nutrients intakes were not affected by the diet, but ether extract intake was higher for the animals fed soy bean-based diets than those fed soybean meal. The digestibility of DM, NDF and CP did not differ. The corrected milk yield differed between treatments; animals on the treatment with soy bean-based concentrate had the lowest production in relation to the others, which did not differ from each other. There was no difference between treatments for milk composition. Thus, soybean meal can be replaced by ground soy beans or roasted soy beans (ground or whole in diets for low-yield cows reared on Brachiaria decumbens pastures with no harm to milkproduction or composition. Therefore, the use of these alternative raw materials is recommended whenever their inclusion represents lower feeding costs.

Consumo, digestibilidade e produção microbiana em novilhos alimentados com diferentes volumosos, com e sem suplementação Intake, digestibility and microbial production in steers fed with different forages, supplemented or not

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S.P. Gomes

2006-10-01

- tifton-85 bermudagrass haylage (PS; 3- brachiaria decumbens hay (FB; 4- brachiaria decumbens hay plus concentrate at 0.5% LW (FB:C1; and 5- brachiaria decumbens hay plus concentrate at 1.0% LW (FB:C2. Tifton-85 bermudagrass haylage provided higher intake of DM (6.0kg/steer/day and TDN (4.2kg/steer/day related to other forages, showing that its use is a good alternative for bovine feeding. The addition of concentrate to the brachiaria decumbens hay increased the forage intake, from 2.7kg/steer/day to 3.9kg/steer/day, constituting a strategy for the poor quality forages use. The highest concentrate C2 intake (1.0% LW increased DM (0.9kg/steer/day and TDN (1.0kg/steer/day intake of FB:C2 dietary, relative to FB:C1 dietary.

Bactérias amonificantes e nitrificantes e teores de amônio e nitrato afetados por plantas de cobertura e fertilizantes nitrogenados

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Edemar Moro

2017-07-01

Full Text Available O objetivo do trabalho foi avaliar o efeito das plantas de cobertura e da fonte de nitrogênio nas bactérias nitrificantes e amonificantes do solo, bem como nos teores de nitrato e amônio. O experimento foi conduzido em um latossolo vermelho distrófico sobre sistema plantio direto (SPD por seis anos. O delineamento experimental foi em blocos casualizados, no esquema de parcelas subdivididas, com quatro repetições. As parcelas foram constituídas por seis espécies de plantas de cobertura do solo (Brachiaria brizantha, Brachiaria decumbens, Brachiaria humidicola, Brachiaria ruziziensis, Pennisetum americanum e Crotalaria spectabilis e as subparcelas pelo controle e três fontes de nitrogênio (1- controle, sem aplicação de N, 2- nitrato de cálcio, 3- sulfato de amônio e 4- sulfato de amônio + dicianodiamida (DCD aplicadas imediatamente após a emergência do arroz na dose de 40 kg ha-1 de N. Foram avaliadas a atividade das bactérias e os teores de nitrato e amônio no solo aos 15 DAE. As plantas de cobertura milheto (Pennisetum americanum, crotalaria (Crotalaria spectabilis; Brachiaria brizantha, B. decumbens; e B. humidicola proporcionaram os maiores teores de amônio no solo; O uso do inibidor de nitrificação (dicianodiamida-DCD inibiu parte das bactérias nitrificantes e proporcionou os maiores teores de amônio no solo; A atividade das bactérias amonificantes e nitrificantes foi maior nas parcelas cultivadas com braquiárias; Plantas de cobertura aliada ao uso de DCD pode ser uma estratégia para aumentar os teores de amônio do solo cultivado sobre SPD

Influência da suplementação com Concentrados nas características de carcaça de bovinos F1 Limousin - Nelore, não-castrados, durante a seca, em pastagens de Brachiaria decumbens

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Santos Eduardo Destéfani Guimarães

2002-01-01

Full Text Available Este trabalho foi realizado na Fazenda Experimental de Felixlândia (MG, da EPAMIG, no período de julho a outubro de 1997, com o objetivo de estudar a influência da suplementação com concentrados sobre as características físicas e o rendimento dos cortes da carcaça em 20 novilhos Limousin-Nelore, não-castrados, com 22-23 meses de idade e peso médio de 459 kg ao abate. Retiraram-se, aleatoriamente, quatro animais de cada um dos cinco tratamentos a que foram submetidos durante 112 dias na época seca, em pastagens diferidas de Brachiaria decumbens. No tratamento T1 (referência, os animais nas pastagens receberam apenas sal mineralizado; nos tratamentos T2 (75% milho, T3 (50% milho, T4 (25% milho e T5 (farelo de trigo, foram fornecidas quantidades médias diárias por animal de 3,70 kg de MS de concentrados (equivalente, em matéria natural, a 1% do PV com 24,1% de PB e NDT variando de 67,8% (T5 - farelo de trigo a 85,6% (T2 - 75% milho. Avaliaram-se as características peso, rendimento e comprimento de carcaça, rendimentos de paleta, acém completo, ponta de agulha, alcatra completa e coxão, espessura de gordura subcutânea, área de olho de lombo, porcentagens na carcaça de tecido adiposo, músculos e ossos e a relação músculo/osso. O fornecimento de suplementos proporcionou a obtenção de carcaças mais pesadas (257,0 vs. 203,9 kg, com menor proporção de ossos (15,76 vs. 21,71%, maior relação músculo:osso (3,6 vs. 2,9 e melhor acabamento quando comparado às carcaças dos animais não-suplementados. Os animais suplementados e não-suplementados não diferiram em relação a rendimento e comprimento de carcaça, rendimentos de paleta, acém completo, alcatra completa e coxão, área de olho de lombo (AOL e porcentagem de músculos na carcaça.

Efeito da temperatura de pré-secagem na digestibilidade e nos fracionamentos da proteína e do carboidrato em gramíneas tropicais

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Oliveira, Augusto Ayres Araújo de

2006-01-01

Amostras de Brachiaria brizantha cv. Marandu, Brachiaria decumbens cv. Basilisk e Panicum maximum cv. Tanzania foram coletadas na época seca do ano. Após a separação botanica dos componentes morfológicos de lamina foliar, colmo e matéria morta, as amostras foram submetidas a temperaturas de pré-secagem de 55º e 65ºC. Foi realizada análise bromatológica para determinação das frações protéicas e de carboidratos e do valor da digestibilidade in vitro da matéria organica (DIVMO). Houve aumento no...

CRESCIMENTO INICIAL DE ESPÉCIES FLORESTAIS NA RECOMPOSIÇÃO DA MATA CILIAR EM TALUDES SUBMETIDOS À TÉCNICA DA BIOENGENHARIA DE SOLOS

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Francisco Sandro Rodrigues Holanda

2010-01-01

development of forest species at riverbank under soil bioengineering technique in São Francisco River. The soil bioengineering technique was composed of longitudinal slope covered with the biotextile (Fibrax 400 BF and sediment retainers (Bemalonga® D40, to reduce the impact of wave water at the slope botton, avoiding the bank undercutting, due to daily variations of water level. Before the biotextile installation the specie, Brachiaria decumbens was sown to promote rapid cover vegetation. Six forest native species such as aroeira vermelha (Schinus terebinthifolius Raddi., pau pombo (Tapirira guianensis Aubl. mulungu (Erythrina velutina Willd. tamboril (Enterolobium contortisiliquum (Vellozo Morong, canafístula (Cassia grandis Lf and pau-ferro (Caesalpinia leiostachya (Bentham Ducke were planted. The species developments were analyzed through the Relative Growth Rate (RGR of the shoot height and crown diameter. After 6 (six months, by the end of evaluations, the bigger number of live individuals was identified in the soil bioengineering treatment. The high density and strong growth of Brachiaria decumbens in the area with biotextile, have contributed to the lower initial tree seedlings development.

Estrategia reproductiva de una hierba perenne: Hypoxis decumbens (Hypoxidaceae

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Elena Raimúndez U

1998-09-01

Full Text Available Se estudió la estrategia reproductiva de Hypoxis decumbens L. (Hypoxidaceae, una hierba perenne con flores hermafroditas, para comprobar las relaciones que se establecen entre sistema reproductivo, forma de vida, ambiente, sistema de polinización y otros caracteres morfológicos y ecológicos. H. decumbens es una especie altamente autógama, que presenta depresión por entrecruzamiento debido a la adaptación de los genotipos autógamos a su ambiente. Los principales polinizadores fueron insectos generalistas como los dípteros. Presentó flores funcionalmente solitarias, actinomórficas, con las partes florales bien expuestas, todas a la misma altura, y anteras de dehiscencia introrsa. La asignación de biomasa fue básicamente hacia estructuras femeninas, como frutos y semillas, lo que se reflejó en una alta eficiencia reproductiva. La relación polen/óvulo fue baja, lo mismo que la relación biomasa de atracción/biomasa de soporte. La unidad de dispersión fue la semilla y el síndrome de dispersión asociado fue la mirmecocoría. En esta especie se presenta un sistema reproductivo mixto, y aunque la mayor proporción de progenie es autógama, no sacrifica la oportunidad de entrecruzarse.The reproductive strategy of Hypoxis decumbens L. (Hypoxidaceae, a perennial herb with hermaphroditic flowers, was studied to check the relations between reproductive system, life form, habitat, pollination system and other morphological and ecological features. The study was done in a secondary deciduous forest with a population of 150-200 plants. Controlled pollinations were done in twenty isolated plants. The results pointed out that H. decumbens is an autogamous species, with outbreeding depression apparently reflecting environmental adaptation of the autogamous genotypes. The main pollinators were generalist insects, like dipterans. It has functionally solitary and actinomorphic flowers, with well exposed floral parts, displayed approximately at the

Atividade microbiana do solo em pomar de laranja em resposta ao cultivo de adubos verdes Soil microbialactivities in orchard citrus as a response to green manure cultivation

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Thais Nucci Buzinaro

2009-06-01

Full Text Available Adubos verdes (AVs são condicionadores do solo utilizados para a melhoria da estrutura e fertilidade do solo. Este estudo avaliou o efeito de Crotalaria spectabilis Roth (crotalária, Cajanus cajan (L Millsp (guandu e Brachiaria decumbens Stapf (braquiária nas propriedades microbiológicas e bioquímicas do solo sob laranjal. As leguminosas foram plantadas nas entrelinhas do laranjal e, após 3 meses, cortadas e lançadas nas entrelinhas. A braquiária, já estabelecida, foi roçada e lançada nas entrelinhas. Após 5 meses, as amostras de solo foram coletadas na entrelinha e na linha, na profundidade de 0-20 cm. O delineamento experimental foi em parcela subdividida. Efeito significativo (pGreen manure (GM is a soil conditioner used to improve soil structure and fertility. This study evaluated the effect of Crotalaria spectabilis Roth (showy rattlebox, Cajanus cajan (L Millsp (pigeonpea and Brachiaria decumbens Stapf (brachiaria on soil microbial and biochemical attributes of the citrus orchard. The leguminous was planted at the intercrops and, after 3 months, they were cut and applied in the intercrops. The grown brachiaria was cut and applied in the intercrops. After 5 months, the soil samples were taken from the rows and intercrops in the depth of 0-20 cm. A split-plot design was used. Significant effect (p < 0.05% from the GM application on the bacteria counts and dehydrogenase and nitrifying activities was obtained an it increased, on average, 20, 39, and 190%, respectively. Fungi number decreased 57%. Urease and solubilizing activities and organic matter and moisture contents were not influenced by the GM application. Among the plants, significant responses were found due to the stimulating activities of dehydrogenase of 57% by pigeonpea, urease 58% by brachiaria, solubilizing 346% by showy rattlebox and nitrifying 236% by pigeonpea or brachiaria in relation to the others GM. These results suggest that GM application for successive

Efeitos de métodos de estabelecimento de braquiária e estilosantes e de doses de calcário, fósforo e gesso sobre alguns componentes nutricionais da forragem Effect of establishment methods of brachiaria and stylosanthes, limestone, gypsum and phosphorus on some forage nutritional components

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Eduardo Eustáquio Mesquita

2002-11-01

Full Text Available Um experimento foi conduzido com o objetivo de avaliar, em dois anos, os efeitos de métodos de estabelecimento (sulcamento: 1,5 e 1,0 m entre linhas em etapa única; 1,5 e 1,0 m em duas e três etapas, respectivamente; aração, gradeação e sulcos espaçados de 1,0 m entre linhas, doses de calcário (25, 50, 75 e 100% da necessidade de calagem-NC, obtida pelo método do Al, Ca e Mg trocáveis, gesso agrícola (0, 230, 940, 1.880 e 2.820 kg/ha, referentes à substituição de 0, 3,0, 12,5, 25,0 e 37,5% do CaO do calcário pelo CaO do gesso, na dose de 100% da NC e P2O5 (50, 100, 150, 200 e 250 kg/ha nas concentrações de minerais (P, K, Ca, Mg e S, proteína bruta (PB, fibra em detergente neutro (FDN, fibra em detergente ácido (FDA e lignina na matéria seca e na DIVMS de Brachiaria decumbens consorciada com Stylosanthes guianensis cv. Mineirão. Os métodos de estabelecimento em duas e três etapas propiciaram maiores concentrações de K na braquiária e Ca no estilosantes. As maiores concentrações de PB na braquiária foram alcançadas com o estabelecimento com aração e gradeação do solo. A substituição do calcário pelo gesso elevou as concentrações de S, Ca e PB na matéria seca da braquiária e do estilosantes e reduziu as concentrações de FDN na gramínea. As doses de P elevaram as concentrações de P, PB e a DIVMS e reduziram as concentrações de FDN na braquiária, melhorando seu valor nutritivo.A field trial was carried out to evaluate the establishment methods (Furrow only: row 1,5 and 1,0 m apart at one time; 1.5 and 1.0 at two and three times, respectively; Plowing and horrowing: row 1,0 apart, limestone (25, 50, 75 e 100% of necessity of limestone, obtained by Al, Ca e Mg exchangeable, gypsum (0, 230, 940, 1.880 e 2.820 kg/ha and P2O5 (50, 100, 150, 200 e 250 kg/ha on minerals concentration (P, K, Ca, Mg e S; crude protein (CP, neutral detergent fiber (NDF, acid detergent acid (ADF and in vitro dry matter

Contaminação salivar da extrusa em novilhos alimentados com diferentes volumosos, com e sem suplementação Saliva contamination in the extrusa in steers fed with different forages, supplemented or not

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S.P. Gomes

2006-12-01

Full Text Available Determinaram-se as alterações nos teores de proteína bruta (PB, compostos nitrogenados não protéicos (NNP, fibra em detergente neutro (FDN, fibra em detergente ácido (FDA, lignina (LIG, cinzas, cálcio (Ca, fósforo (P, magnésio (Mg, potássio (K e sódio (Na de alimentos usados para novilhos, provocadas pela contaminação da extrusa pela saliva. Foram utilizados cinco novilhos fistulados no rúmen e esôfago, cinco dietas e cinco períodos experimentais. Os tratamentos foram: capim-elefante picado (CE, capim-elefante obtido em pastejo simulado (CES, capim-braquiária obtido em pastejo simulado (CBS, pré-secado de capim-tifton 85 (PS, feno de capim-braquiária (FB1, feno de capim-tifton 85 (FT, feno de capim-braquiária e concentrado a 0,5% PV (FB2 e feno de capim-braquiária e concentrado 1,0% PV (FB3. A presença de saliva na extrusa não alterou (P>0,05 o teor de proteína bruta dos alimentos. Os teores de NNP foram superestimados (PAlterations on the levels of crude protein (CP, non-protein nitrogen compounds (NNP, neutral detergent fiber (NDF, acid detergent fiber (ADF, lignin (LIG, ash, calcium (Ca, phosphorus (P, magnesium (Mg, potassium (K and sodium (Na of feeds used for steers, caused by the saliva contamination in the extrusa, were evaluated. Five steers, fistulated in the rumen and esophagus were fed five diets, in five experimental periods. The treatments were: chopped elephantgrass (CE, elephantgrass obtained by hand-plucked (CES, Brachiaria decumbens obtained by hand-plucked (CBS, Tifton-85 bermudagrass haylage (PS, Brachiaria decumbens hay (FB1, Brachiaria decumbens hay and concentrate at 0.5% LW (FB2, and Brachiaria decumbens hay and concentrate at 1.0% LW (FB3. The extrusa CP content was not affected (P>0.05 by saliva contamination. The NNP levels were overestimated (P<0.05 in the extrusa in 135.0%. The NDF levels were underestimated (P<0.05 in 3.4%. The ADF and LIG contents were overestimated (P<0.05 in extrusa

Efeito de períodos de controle de plantas daninhas sobre o desenvolvimento inicial de plantas de eucalipto Effects of weed control periods on initial growth and development of eucalypt

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R.E.B. Toledo

2000-01-01

Full Text Available O objetivo deste trabalho foi estudar os efeitos dos períodos de convivência e de controle de Brachiaria decumbens sobre o desenvolvimento inicial de clones de Eucalyptus grandis x Eucalyptus urophylla. Para isso, um ensaio foi conduzido, no município de Três Lagoas-MS, no período de janeiro a dezembro de 1997. Os tratamentos experimentais consistiram de diferentes épocas e períodos de convivência das plantas daninhas na cultura do eucalipto. As épocas foram divididas em dois grupos. No primeiro, a convivência se iniciava no transplante das mudas e era estendida até 28, 56, 84, 112, 140, 168, 224, 252 e 364 dias após. No segundo grupo, a convivência se iniciava aos 0, 28, 56, 84, 112, 140, 168, 224 e 252 dias após o transplante e era estendida até o final de um ano. As principais plantas daninhas que ocorreram na área experimental foram Brachiaria decumbens e Spermacocea latifola. As plantas jovens de eucalipto foram bastante suscetíveis à interferência das plantas daninhas, apresentando um período anterior à interferência inferior a 14-28 dias. Para assegurar o desenvolvimento da cultura, o período total de prevenção à interferência foi de 140 dias, e o período crítico de prevenção à interferência, de 14-28 a 140 dias após o transplante, considerando o índice de 5% de redução em diâmetro.A field trial was carried out in Três Lagoas-MS, Brazil, from January to December of 1997, to study the effects of control and coexistence period of Brachiaria decumbens on the growth of Eucalyptus grandis x Eucalyptus urophylla clones. The experimental design was a complete randomized block design, with four replications. The treatments consisted of different periods of weed-eucalypt association. The periods were divided in two groups. In the first one, the weed-eucalypt coexistence initiated during the eucalypt transplanting, continuing up to 28, 56, 112, 140, 168, 224, 252 and 364 days after it. In the second group, the

Seletividade de herbicidas aplicados em pré-emergência em gramíneas forrageiras Selectivity of pre-emergence herbicides applied on forage grasses

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A.C.P Rodrigues-Costa

2011-09-01

Full Text Available O presente trabalho teve o objetivo de avaliar a seletividade de herbicidas aplicados em pré-emergência sobre a produção e a qualidade de sementes de Brachiaria brizantha cv. Marandu e Brachiaria decumbens cv. Basilisk. Os herbicidas avaliados foram: diuron (800 e 1.600 g ha-1, ametryn (625 e 1.250 g ha-1, imazaquin (75 e 150 g ha-1, imazethapyr (50 e 100 g ha-1 e flumetsulam (70 e 140 g ha-1, além de uma testemunha sem aplicação de herbicidas. As espécies foram avaliadas separadamente no campo. Os experimentos foram instalados no delineamento em blocos casualizados com quatro repetições. Os herbicidas ametryn (625 g ha-1, imazaquin (75 e 150 g ha-1, imazethapyr (50 e 100 g ha-1 e flumetsulam (70 e 140 g ha-1 foram os que proporcionaram maior seletividade às plantas de B. brizantha, enquanto para B. decumbens o diuron (800 e 1.600 g ha-1, o ametryn (625 e 1.250 g ha-1 e o imazethapyr (50 e 100 g ha-1 foram mais seletivos, destacando-se o diuron na menor dose. Contudo, os herbicidas avaliados não alteram a produção e a qualidade das sementes das forrageiras estudadas.This study aimed to evaluate the selectivity of pre-emergence herbicides on yield and seed quality of Brachiaria brizantha cv. Brizantha and Brachiaria decumbens cv. Basilisk. The herbicides evaluated were: diuron (800 and 1.600 g ha-1, ametryn (625 and 1.250 g ha-1, imazaquin (75 and 150 g ha-1, imazethapyr (50 and 100 g ha-1 and flumetsulam (70 and 140 g ha-1, plus a control without herbicide application. The species were evaluated separately in the field. The experiments were arranged in a randomized block design with four replications. The herbicides ametryn (625 g ha-1, imazaquin (75 and 150 g ha-1, imazethapyr (50 and 100 g ha-1, and flumetsulam (70 and 140 g ha-1 provided the highest selectivity to B. brizantha plants, while for B. decumbens, diuron (800 and 1.600 g ha-1, ametryn (625 and 1.250 g ha-1, and imazethapyr (50 and 100 g ha-1 were more selective

Molecular Characterizations of Kenyan Brachiaria Grass Ecotypes with Microsatellite (SSR Markers

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Naftali Ondabu

2017-02-01

Full Text Available Brachiaria grass is an emerging forage option for livestock production in Kenya. Kenya lies within the center of diversity for Brachiaria species, thus a high genetic variation in natural populations of Brachiaria is expected. Overgrazing and clearing of natural vegetation for crop production and nonagricultural uses and climate change continue to threaten the natural biodiversity. In this study, we collected 79 Brachiaria ecotypes from different parts of Kenya and examined them for genetic variations and their relatedness with 8 commercial varieties. A total of 120 different alleles were detected by 22 markers in the 79 ecotypes. Markers were highly informative in differentiating ecotypes with average diversity and polymorphic information content of 0.623 and 0.583, respectively. Five subpopulations: International Livestock Research Institute (ILRI, Kitui, Kisii, Alupe, and Kiminini differed in sample size, number of alleles, number of private alleles, diversity index, and percentage polymorphic loci. The contribution of within‐the‐individual difference to total genetic variation of Kenyan ecotype population was 81%, and the fixation index (FST = 0.021 and number of migrant per generation (Nm = 11.58 showed low genetic differentiation among the populations. The genetic distance was highest between Alupe and Kisii populations (0.510 and the lowest between ILRI and Kiminini populations (0.307. The unweighted neighborjoining (NJ tree showed test ecotypes grouped into three major clusters: ILRI ecotypes were present in all clusters; Kisii and Alupe ecotypes and improved varieties grouped in clusters I and II; and ecotypes from Kitui and Kiminini grouped in cluster I. This study confirms higher genetic diversity in Kenyan ecotypes than eight commercial varieties (Basilisk, Humidicola, Llanero, Marandú, MG4, Mulato II, Piatá and Xaraés that represent three species and one three‐way cross‐hybrid Mulato II. There is a need for further

Plantas de cobertura no controle de plantas daninhas na cultura do tomate em plantio direto Cover crops used to control weeds under the no-tillage tomato production system

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A.C. Silva Hirata

2009-01-01

Full Text Available O plantio direto do tomateiro é um sistema que busca maior sustentabilidade, porém são escassas as informações sobre o manejo de plantas daninhas nessa nova modalidade de cultivo. O objetivo deste trabalho foi avaliar cinco tipos de cobertura do solo (Brachiaria decumbens, B. ruziziensis, Pennisetum glaucum, comunidade infestante e tratamento sem cobertura vegetal para plantio direto do tomateiro rasteiro, conduzido no sistema meia estaca, em complementação ao controle químico com herbicidas. P. glaucum foi a espécie que proporcionou maior cobertura do solo até a colheita do tomate; todavia, a taxa de decomposição da palha foi maior que a das demais coberturas. As coberturas de solo compostas pelas gramíneas forrageiras B. decumbens, B. ruziziensis e Pennisetum glaucum reduziram a densidade e a massa seca das plantas daninhas. O uso da comunidade infestante para obtenção de palha promoveu reduzida cobertura do solo e elevada emergência de plantas daninhas, semelhantes às do solo sem cobertura. B. decumbens apresentou rebrota durante o ciclo do tomateiro, o que não ocorreu com B. ruziziensis.Tomato no tillage system is a more sustainable system. However, information about weed management in this new cultivation modality is scarce. The objective of this work was to evaluate five vegetation covers (Brachiaria decumbens, B. ruziziensis, Pennisetum glaucum, community weed and the treatment without vegetable covering for no tillage system of the staked processing tomato crop combined with weed chemical control. P. glaucum provided the most soil cover to the tomato crop, although straw decomposition rate was higher than those of the other covers. The soil cover by the forage grasses B. decumbens, B. ruziziensis and Pennisetum glaucum reduced the density and dry mass of the weeds. The use of the community weeds for straw obtaining promoted reduced covering of the soil and larger emergency of weeds, similar to the treatment without

Eficácia de herbicidas inibidores da ACCase no controle de gramíneas em lavouras de soja Efficacy of ACCase-inhibiting herbicides in controlling grass weeds in soybean crops

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A.L.L. Barroso

2010-01-01

Full Text Available Objetivou-se com este trabalho avaliar a eficácia de herbicidas inibidores da ACCase, aplicados isoladamente ou em associações, no controle das espécies de plantas daninhas pertencentes à família das gramíneas Brachiaria decumbens, Digitaria ciliaris, Eleusine indica, Brachiaria plantaginea e Cenchrus echinatus, na cultura da soja. O experimento foi conduzido em campo, em delineamento de blocos ao acaso com quatro repetições. Os tratamentos avaliados foram: clethodim (84 g ha-1, clethodim + quizalofop-p-ethyl (48 + 40 g ha-1, [clethodim + fenoxaprop-p-ethyl] (50 + 50 g ha-1, sethoxydim (230 g ha-1, tepraloxydim (100 g ha-1, fluazifop-p-butyl (125 g ha-1, haloxyfop-methyl (60 g ha-1 e testemunha sem herbicida. A convivência das plantas de soja com as gramíneas infestantes resultou em perda significativa na produtividade de grãos. Os melhores níveis de controle de B. decumbens foram verificados com a utilização de haloxyfop-methyl. Tepraloxydim pode ser considerado seletivo a B. decumbens. Nenhum tratamento proporcionou controle final de D. ciliaris superior a 90%, porém menor eficiência foi verificada quando se aplicaram sethoxydim e fluazifop-p-butyl. Apenas os tratamentos sethoxydim e [clethodim + fenoxaprop-p-ethyl] não mostraram controle satisfatório de E. indica. B. plantaginea foi a espécie mais facilmente controlada pelos herbicidas avaliados; no entanto, haloxyfop-methyl, tepraloxydim, clethodim e [clethodim + fenoxaprop-p-ethyl] se destacaram no controle dessa invasora. A adição de quizalofop-p-ethyl ao clethodim proporcionou incremento significativo no controle de C. echinatus. Também os herbicidas haloxyfop-methyl e tepraloxydim apresentaram controle satisfatório dessa espécie daninha.The objective of this work was to evaluate the efficacy of ACCase-inhibitors (ariloxyfenoxypropionates and cyclohexanodiones, applied alone or in combination, in controlling the grass weed species Brachiaria decumbens, Digitaria

Banco de sementes de plantas daninhas em solo cultivado com pastagens de Brachiaria brizantha e Brachiaria humidicola de diferentes idades Weed seed bank in soil cultivated with pasture of Brachiaria brizantha and Brachiaria humidicola of different ages

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D.S.M. Silva

2001-08-01

Full Text Available Estudou-se o banco de sementes do solo de uma pastagem de Brachiaria brizantha com 4 anos de idade e de pastagens de Brachiaria humidicola com 4, 15 e 20 anos de idade, localizadas no nordeste do Estado do Pará. Objetivou-se avaliar a influência da espécie forrageira e da idade da pastagem no tamanho e na composição do banco de sementes de plantas daninhas do solo. Cada pastagem foi dividida em cinco áreas de aproximadamente 500 m², sendo retiradas, de cada área, 10 subamostras de solo na profundidade de 0-10 cm. Cada amostra composta das 10 subamostras de solo foi homogeneizada, identificada, distribuída em bandeja de plástico e levada para germinar em casa de vegetação durante um período de 15 meses. O banco de sementes do solo da pastagem de B. brizantha foi em torno de 10 vezes menor que o da pastagem de B. humidicola de mesma idade. Com relação ao efeito da idade da pastagem, entre as pastagens de B. humidicola, o banco de sementes foi menor naquela de 20 anos de idade (1.247 sementes m-2, não tendo sido detectada diferença significativa entre as pastagens de 15 (11.602 sementes m-2 e 4 (9.486 sementes m-2 anos de idade. As famílias botânicas Cyperaceae, Rubiaceae e Labiateae foram as de maior predominância entre as plantas daninhas infestantes da área, em todos os tratamentos estudados.The objective of this work was to study the soil seed bank of a four-year-old Brachiaria brizantha pasture soil, and in pasture soils of four, 15 and 20 year-old Brachiaria humidicola, in northeastern Pará, Brazil, to evaluate the influence of the forage species and pasture age on weed seed bank size and composition. Each pasture area was divided into five plots of about 500 m², from which 10 soil sub-samples were collected at a depth of 0-10 cm. The soil from each plot was mixed, identified, placed in plastic trays, and put to germinate in a greenhouse during a 15-month period. The seed bank of the four-year-old B. brizantha pasture

Controle de Brachiaria subquadripara e Brachiaria mutica através de diferentes herbicidas aplicados em pós-emergência Control of Brachiaria subquadripara and Brachiaria mutica by different herbicides applied post-emergence

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C.A. Carbonari

2003-01-01

Full Text Available Foram realizados dois experimentos, com objetivo de avaliar a suscetibilidade de Brachiaria subquadripara e Brachiaria mutica a diferentes herbicidas aplicados em pósemergência. Os herbicidas e doses testados foram: glyphosate (Rodeo a 2.400, 3.360 e 4.320 g e.a. ha-1 com Aterbane a 0,5% v/v; glyphosate a 2.400, 3.360 e 4.320 g e.a. ha-1 com Silwet a 0,1% v/v; imazapyr (Arsenal a 750 e 1.500 g e.a. ha-1; e diquat (Reward a 400 e 800 g i.a. ha-1 com aplicação seqüencial. Manteve-se uma testemunha sem aplicação de herbicidas. As parcelas experimentais foram constituídas de caixas d'água de 60 x 60 x 45 cm, com 55 L de solo. A aplicação foi realizada quando as plantas se encontravam a 45 e 65 cm de altura para B. subquadripara e B. mutica, respectivamente. Foi utilizado um pulverizador costal, a pressão constante de CO2 (2 bars, pontas 110.02 XR, com um consumo de calda de 200 L ha-1. O controle foi avaliado visualmente, através de escala percentual de notas, além de se avaliar a massa seca das plantas. O herbicida glyphosate nas doses de 3.360 e 4.320 g e.a. ha-1, independentemente do adjuvante testado, proporcionou controle excelente para as duas espécies, porém as parcelas que receberam glyphosate a 2.400 g e.a. ha-1 apresentaram controle apenas satisfatório. O herbicida imazapyr nas doses de 750 e 1.500 g e.a. ha-1 proporcionou controle eficiente para B. subquadripara e excelente para B. mutica. Já o herbicida diquat, apesar de duas aplicações e independentemente da dose utilizada, mostrou-se ineficiente no controle das duas espécies.Two experiments were carried out to evaluate the susceptibility of Brachiaria subquadripara and Brachiaria mutica to different herbicides applied in post-emergence. The herbicides and doses used were: glyphosate (Rodeo at 2,400, 3,360 and 4,320 (g a.e. ha-1 plus Aterbane 0.5% v/v; glyphosate at 2,400, 3,360 and 4,320 (g a.e. ha-1 plus Silwet 0.1% v/v; imazapyr (Arsenal at 750 and 1,500 (g a

Weather and plant age affect the levels of steroidal saponin and Pithomyces chartarum spores in Brachiaria grass

Science.gov (United States)

Brachiaria species are cultivated worldwide in tropical and subtropical climates as the main forage source for ruminants. Numerous tropical and warm-season grasses cause hepatogenous photosensitization, among them several species of Brachiaria. Steroidal saponins present in these plants may be respo...

CORRELAÇÕES ENTRE CARACTERÍSTICAS MORFOGÊNICAS E ESTRUTURAIS EM PASTOS DE CAPIM-BRAQUIÁRIA

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Manoel Eduardo Rozalino Santos

2012-03-01

Full Text Available The analysis of both morphogenetic and structural characteristics of pasture allows us to understand the response patterns of the plant to the environment. Thus, this study was conducted to evaluate the associations between the morphogenetic and structural characteristics of Brachiaria decumbens under continuous grazing by cattle. The development of individual tillers in pastures was evaluated under two grazing management strategies during three seasons (winter, spring and summer. Pearson correlations between variables were estimated. The lengths of leaf and stem, number of tillers and leaves per tiller, rates of leaf appearance and elongation of leaf and stem of B. decumbens were positively correlated. There was a negative relationship between appearance and lifespan of leaves (r = -0.89. However, positive correlations between leaf appearance rate and number of tillers (r = 0.64 and between length of stem and leaf senescence rate (r = 0.63 were determined. The B. decumbens modifies its morphogenesis to better adapt to climate and grazing management.

Renovação de pastagem degradada de capim-gordura com a introdução de forrageiras tropicais adubadas com nitrogênio ou em consórcios Renewing the degraded Melinis minutiflora pasture by introduction of tropical forages fertilized with nitrogen or under mixture cropping system

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Luciano de Melo Moreira

2005-04-01

, melhorando a qualidade do pasto.This study was carried out to evaluate the productivity and quality of either Brachiaria decumbens Stapf. cv. Basilisk and Hyparrhenia rufa (Ness Stapf. grasses fertilized with nitrogen (N or mixed with stylosanthes (Stylosanthes guianensis (Aubl. Swartz cv. Mineirão, introduced into a degraded pasture. Both grasses were evaluated, as well as four doses of nitrogen (0, 50, 100 and 150 kg/ha and two treatments that consisted of mixing B. decumbens and S. guianensis as well as H. rufa and S. guianensis. After forages were established, two evaluations were also performed (harvests. The dry matter (DM yields of B. decumbens increased from 1,824 up to 4,604 kg/ha and from 1,019 to 2,149 kg/ha in both respective harvests, when the extreme N doses were compared, but H. rufa showed no response. The crude protein (CP content in B. decumbens increased from 3.18 up to 5.68 dag/kg at the first harvest only, whereas H. rufa showed an increment from 2.53 to 3.72 dag/kg and from 7.32 to 8.45 dag/kg in both respective harvests, compared to the extreme doses. The contents of both neutral detergent fiber (NDF and acid detergent fiber in the grasses were not affected by N application. When N doses increased, the P contents in both grasses and K contents in B. decumbens were reduced at both harvests. Most contents of Ca and Mg in grasses were not affected by N at both harvests. The average DM yields of both mixtures were superior to the average yields of both fertilized grasses, as showing increments of 42.62% and 15.00% in forage yield at the first and second harvests, respectively. In general, the mixed forages showed higher contents of CP and Ca, but lower NDF values than those N-fertilized pure grasses, therefore improving the quality of the pasture.

Detecting bacterial endophytes in tropical grasses of the Brachiaria ...

African Journals Online (AJOL)

Plant-growth-promoting (PGP) bacteria include a diverse group of soil bacteria thought to stimulate plant growth by various mechanisms. Brachiaria forage grasses, of African origin, are perennials that often grow under low-input conditions and are likely to harbour unique populations of PGP bacteria. Three bacterial strains ...

Oxidizable carbon and humic substances in rotation systems with brachiaria/livestock and pearl millet/no livestock in the Brazilian Cerrado

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A. Loss

2013-02-01

Full Text Available The crop-livestock integration system significantly increases the carbon content in chemical fractions of soil organic matter (SOM. This study aimed to evaluate chemical indicators of SOM attributes for sites under brachiaria/livestock and pearl millet/no livestock in Goias, Brazil. A third area covered with natural Cerrado vegetation (Cerradão served as reference. Soil was randomly sampled at 0-5, 5-10, 10-20 and 20-40 cm. Total organic carbon stocks (TOC, oxidizable carbon fractions (OCF (F1>F2>F3>F4, carbon content in the humin (C-HUM, humic acid (C-HAF and fulvic acid (C-FAF fractions were evaluated. F1/F4, F1+F2/F3+F4, C-HAF/C-FAF and (C-HAF+C-FAF/C-HUM indices were calculated, as well as stocks chemical SOM fractions. Brachiaria/livestock produced greater TOC stocks than pearl millet/no livestock (0-5, 5-10 and 10-20 cm. In terms of OCF, brachiaria/livestock generally exhibited higher levels in F1, F2, F4 and F1/F4 than pearl millet/no livestock. C-HUM (0-10 cm and C-HAF (0-20 cm stocks were larger in brachiaria/livestock than pearl millet/no livestock. Compared to the Cerradão, brachiaria/livestock locations displayed higher values for TOC (5-10 and 10-20 cm, C-HAF and C-HAF/C-FAF (5-10 cm stocks. TOC, C-HAF stock and OCF show that land management with brachiaria/livestock was more efficient in increasing SOM than pearl millet/no livestock. Moreover, when compared with pearl millet/no livestock, brachiaria/livestock provided a more balanced distribution of very labile (F1 and recalcitrant (F4 carbon throughout soil layers, greater SOM humification. Brachiaria/livestock leads to higher values of F1 and F4 in depth when compared to pearl millet/livestock and provides a more homogeneous distribution of C-FAF and C-HAF in depth compared to Cerradão.

Intercropping of corn, brachiaria grass and leguminous plants: productivity, quality and composition of silages

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Patrícia Monteiro Costa

2012-10-01

Full Text Available The present study was carried out with the objective to evaluate the productive and qualitative characteristics of forages produced in systems of intercropping of corn, brachiaria grass and different leguminous plants. Productivity, bromatological composition and the fermentative profile of the silages from the following treatments were evaluated: corn in exclusive cultivation (CEC; intercropping of corn with brachiaria grass (CB; intercropping of corn, brachiaria grass and Calopogonium mucunoides (CBCal; intercropping of corn, brachiaria grass and Macrotyloma axillare (CBMac; and intercropping of corn, brachiaria grass and Stylozanthes capitata (CBSty. The experimental design utilized was completely randomized. For each type of cultivation, five plots or replications of three linear meters were harvested, and the material was separated. The variables assessed were: dry matter productivity per area; dry matter productivity of corn per area; crude protein production per area and productivity of total digestible nutrients per area. The material originated from the cultures was ensiled, with dry matter between 28 and 32%. After, the material was placed and compacted appropriately in bucket silos. A sample was collected from each replication for determination of the contents of DM, crude protein (CP, ether extract (EE, lignin, neutral and acid detergent fibers (NDF and ADF and TDN. A fraction of the sample of silages from each treatment was compressed for extraction of the juice and determination of the silage quality. There was difference between the forms of cultivation for the dry matter production per hectare. The CEC with production of 11920.1 kg DM/ha did not differ from CB (8997.41 kg DM/ha or CBCal (10452.10 kg DM/ha; however, it was superior to CBMac (8429.75 kg DM/ha and to CBSty (8164.83 kg DM/ha. The contents of DM, CP, NDF, ADF, lignin and TDN did not differ between the silages from the different treatments. All the silages presented

Perfil químico da parede celular e suas implicações na digestibilidade de Brachiaria brizantha e Brachiaria humidicola Chemical profile of cell wall and its implications on Brachiaria brizantha and Brachiaria humidicola digestibility

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Cláudio José F. Alves de Brito

2003-12-01

Full Text Available No presente trabalho foram determinadas a composição química e a digestibilidade de diversas frações de Brachiaria brizantha e Brachiaria humidicola, após 70 dias de crescimento. O delineamento experimental foi inteiramente casualizado com cinco repetições para cada espécie. As plantas coletadas foram subdivididas nas frações apical, mediana e basal para as folhas e mediana e basilar para caules, de acordo com sua localização. Foram determinadas as concentrações de fibra em detergente neutro (FDN, proteína bruta (PB, lignina, ácido p_cumárico, ácido ferúlico e açúcares neutros (glicose, xilose e arabinose e a digestibilidade in situ após 48 horas de período de incubação ruminal. As diferentes frações das espécies estudadas apresentam distinta composição química, cujos efeitos são observados na digestibilidade. A B. brizantha apresentou maiores concentrações de FDN no caule e PB nas folhas. Isto resultou em coeficientes de digestibilidade maiores em relação à B. humidicola. A diferença de digestibilidade entre caule e folhas e nas frações mais velhas pode estar relacionada ao tipo de condensação da lignina presente nos tecidos. Evidências na concentração e na proporção dos ácidos p_cumárico e ferúlico sugerem esta relação. A concentração de ácidos fenólicos esteve relacionada com a digestibilidade da matéria seca e a lignina com a digestibilidade da FDN. A análise dos ácidos fenólicos pode se constituir em importante ferramenta para avaliar o grau de condensação da lignina na parede celular dos diferentes tecidos das plantas forrageiras. A concentração de açúcares neutros não apresentou um padrão definido na composição dos diferentes tecidos. A arabinose foi o único açúcar que apresentou relações com a digestibilidade da matéria seca e com a concentração de ácidos fenólicos.In the present paper the chemical composition and digestibility of several Brachiaria

Produtividade e valor nutritivo da Brachiaria brizantha cv. Marandu em um sistema silvipastoril Productivity and nutritional value of Brachiaria brizantha cv. Marandu in a silvopastoral system

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L.F. Sousa

2007-08-01

Full Text Available O experimento foi realizado em sistema silvipastoril (Ssp localizado no bioma de Cerrado, no município de Lagoa Santa, Minas Gerais, no ano agrícola de 2004-2005. Avaliou-se a influência do Ssp composto pela arbórea bolsa-de-pastor (Zeyheria tuberculosa sobre os parâmetros produção, atributos morfogênicos, composição bromatológica e valor nutritivo da gramínea Brachiaria brizantha cv. Marandu, e os efeitos sobre as condições microclimáticas. O delineamento experimental foi em blocos ao acaso, com cinco blocos (épocas de corte, dois tratamentos (T1 - B. brizantha cv. Marandu sombreada com a Z. tuberculosa e T2 - B. brizantha cv. Marandu, a pleno sol e três repetições (parcelas. O sombreamento proporcionado pela Z. tuberculosa, apesar de reduzir a produção de matéria seca (MS da gramínea, favoreceu o aumento do teor de proteina bruta (PB e não alterou a produção de PB/ha e nem afetou a concentração de FDN. Os teores de FDA foram mais altos que os encontrados a pleno sol, o que provavelmente resultou em menor degradabilidade in vitro da MS e da matéria orgânica, não alterando a degradabilidade efetiva.The experiment was carried out in a Silvopastoral system (Sps located in Brazilian Savannah, Lagoa Santa county, Minas Gerais State, during the agricultural year of 2004-2005. It was studied the influence of Sps formed by "Bolsa de Pastor" (Zeyheria tuberculosa on the production, morphogenic attributes, bromatological composition and nutritional value of the graminaceous Brachiaria brizantha cv. Marandu as well as on the microclimatic aspects. The Sps was established in 1982, in a red-yellow latossol by the natural regeneration process. The experiment was based on a randomized block design, with 5 blocks (cutting times, 2 treatments (T1 - B. brizantha cv. Marandu shaded by Z. tuberculosa and T2 - B. brizantha cv. Marandu at open sky and three repetitions (plots. Although the DM production of the graminaceous in the Sps

Densidade populacional de Pratylenchus spp. em pastagens de Brachiaria spp. e sua influência na disponibilidade e na qualidade da forragem

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Cassia de Carvalho

2013-02-01

Full Text Available Objetivando avaliar a densidade populacional de Pratylenchus brachyurus e Pratylenchus zeae, associados à Brachiaria brizantha, B. decumbens e B. humidicola, e sua influência na disponibilidade e na qualidade da forragem, realizou-se este trabalho. O experimento foi conduzido na Agropecuária Hisaeda, em Terenos, MS. Coletaram-se amostras de solo, raízes e parte aérea, em dez repetições ao acaso, de 1 m² cada, dos seguintes tratamentos: Bom, Intermediário e Ruim, caracterizados visualmente, considerando-se a percentagem de material verde das plantas. As densidades de P. brachyurus e P. zeae foram avaliadas nas amostras de solo e raízes. Na parte aérea, avaliou-se a disponibilidade de matéria seca dos materiais verde, morto e da rebrota, estado nutricional das plantas e qualidade da forragem. A fertilidade do solo foi determinada em todas as unidades amostrais. Ambos os nematoides foram identificados em todas as amostras, com maior número nas raízes (entre 87-311 P. brachyurus e 1-61 P. zeae.10 g-1 que no solo (de 0-8 P. brachyurus a 1-39 P. zeae.200 cm-3, no entanto, não houve diferenças significativas, na quantidade de espécimes, entre os tratamentos. Considerando-se que essas forrageiras são perenes e hospedam Pratylenchus spp., há tendência ao aumento da população desses patógenos, ao longo do tempo, podendo se tornar um sério problema fitossanitário.

The use of RAPD fingerprinting to detect genetic variation of a selected signal grass mutant

International Nuclear Information System (INIS)

Affrida Abu Hassan; Ghazali HAzhar Mohamad; Abdul Rahim Harun

2002-01-01

Signal grass (Brachiaria decumbens) has been used for many years as grazing pasture for ruminants but it may know to be toxic to small ruminants. Mutagenesis provides an alternative approach to create phenotypic variability in the grass that might be free from toxicity and allow greater selection potential for desired characteristics. The mutant of Brachiara decumbens, which was obtained through induced mutation by gamma irradiation at dose 900 Gh showed phenotypic changes in term of tiller number, leaf to stem ratio and internode length. The variations caused by irradiation were detected by Random Amplified Polymorphic DNA (RAPD) analysis. Decamer oligonucleotide primers were used to generate DNA profiles. 575 bp polymorphic DNA band was observed between control and the mutant. RAPD has been proven to be useful to detect polymorphism between mutants and the control. (Author)

Penggunaan Pupuk Kandang pada Padang Rumput di Lahan Kering Sulawesi Tenggara

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Harapin Hafid H

2007-12-01

Full Text Available Generally, the permanent pasture of dry farming in South East Sulawesi is dominated by the perennial grass and coppi plant, which have very low palatability and benefit for livestock. The aim of the research was to increase the productivity of pasture in South East Sulawesi by introducing perennial grasses and manure application. The experiment was conducted in UPTD and analytical laboratory of FMIPA from April to September 2006 using three types of perennial grasses i.e. Brachiaria decumbens, Paspalum dilatatum and Cynodon plectostachyrus. Perception conducted to calculate the botanical composition and soil properties before and after the treatment. The field experiment was carried out as two factorial experiment arranged in Randomized Block Design. The first factor was the species of perennial grass and the second factor was different level of manure fertilizer. The result of the experiment showed that the crude fibre content of B. decumbens was lower than those of P. dilatatum and C. plectostachyrus. The crude fibre content increased with the increasing manure application. But the protein content of B. decumbens was higher than those of P. dilatatum and C. plectostachyrus. It is suggested to plant B. decumbens to get higher quality forage for livestock in South East Sulawesi.

Variabilidade espacial e temporal da vegetação em pastos de capim braquiária diferidos Spatial and temporal variability of vegetation on deferred signalgrass pastures

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Manoel Eduardo Rozalino Santos

2010-04-01

Full Text Available Avaliou-se a variabilidade espacial e temporal de características descritoras da condição de pastos diferidos de Brachiaria decumbens cv. Basilisk (capim-braquiária. Os tratamentos consistiram de combinações dos períodos de diferimento da pastagem (73, 103, 131 e 163 dias com os períodos de pastejo (29, 57 e 85 dias. Utilizou-se esquema de parcelas subdivididas e delineamento em blocos casualizados com duas repetições. Foi determinada a dispersão dos valores de altura do pasto, altura da planta estendida e do índice de tombamento do pasto. A variabilidade espacial da altura do pasto aumentou de forma linear com o período de diferimento, porém não foi influenciada pelo período de pastejo. O coeficiente de variação da altura da planta estendida diminuiu linearmente em pastos submetidos aos maiores períodos de diferimento e não foi afetado pelo período de pastejo. A variabilidade do índice de tombamento, no entanto, apresentou resposta quadrática ao período de diferimento, com ponto de máximo correspondente ao coeficiente de variação de 38,25% aos 130 dias. Em pastagens diferidas por curto período (73 dias, ocorreu variação negativa do coeficiente de variação durante o período de pastejo. Pastos de capimbraquiária sob diferimento por longos períodos possuem maior variabilidade da altura do pasto e menor heterogeneidade da altura da planta estendida. Além do efeito temporal, ocorre grande variabilidade espacial nas pastagens de capim-braquiária diferidas.It was evaluated spatial and temporal variability of status descriptive characters of Brachiaria decumbens (signalgrass cv. Basilisk deferred pastures. Treatments consisted of combinations of pasture deferring periods (73, 103, 131 and 163 days with grazing periods (29, 57 and 85 days. Randomized block design with two repetitions and subdivided plots was used. It was determined the dispersion of pasture height (PH, stretched plant height (SPH and falling index

The identification of and relief from Fe3+ inhibition for both cellulose and cellulase in cellulose saccharification catalyzed by cellulases from Penicillium decumbens.

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Wang, Mingyu; Mu, Ziming; Wang, Junli; Hou, Shaoli; Han, Lijuan; Dong, Yanmei; Xiao, Lin; Xia, Ruirui; Fang, Xu

2013-04-01

Lignocellulosic biomass is an underutilized, renewable resource that can be converted to biofuels. The key step in this conversion is cellulose saccharification catalyzed by cellulase. In this work, the effect of metal ions on cellulose hydrolysis by cellulases from Penicillium decumbens was reported for the first time. Fe(3+) and Cu(2+) were shown to be inhibitory. Further studies on Fe(3+) inhibition showed the inhibition takes place on both enzyme and substrate levels. Fe(3+) treatment damages cellulases' capability to degrade cellulose and inhibits all major cellulase activities. Fe(3+) treatment also reduces the digestibility of cellulose, due to its oxidation. Treatment of Fe(3+)-treated cellulose with DTT and supplementation of EDTA to saccharification systems partially relieved Fe(3+) inhibition. It was concluded that Fe(3+) inhibition in cellulose degradation is a complicated process in which multiple inhibition events occur, and that relief from Fe(3+) inhibition can be achieved by the supplementation of reducing or chelating agents. Copyright © 2013 Elsevier Ltd. All rights reserved.

Aplicação de formononetina na colonização e esporulação de fungos micorrízicos em braquiária Formononetin application on colonization and sporulation of arbuscular mycorrhizal fungi in Brachiaria

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Cândido Barreto de Novais

2009-05-01

Full Text Available O objetivo deste trabalho foi avaliar o efeito de aplicações de Mycoform na colonização micorrízica e esporulação de 13 isolados de fungos micorrízicos arbusculares em Brachiaria decumbens. O experimento foi conduzido em casa de vegetação, em solo esterilizado, com delineamento experimental inteiramente casualizado, em arranjo fatorial 3x13, com cinco repetições. O produto foi aplicado no plantio e foi ou não aplicado uma segunda vez 60 dias depois, na quantidade de 2 mg kg-1 de solo. Aos 150 dias de crescimento das plantas, foram coletadas amostras de raízes e de solo rizosférico, para a avaliação de colonização radicular e densidade de esporos. Houve estímulo do Mycoform nos parâmetros avaliados, efeito que variou com os isolados estudados. Foi observado efeito significativo da aplicação do Mycoform na colonização das raízes pelos isolados Glomus clarum DCS 09 e DCS 10, Paraglomus occultum DCS 06 e Acaulospora delicata DCS 02 e na esporulação dos isolados G. clarum DCS 09 e DCS 10, P. occultum DCS 06 e DCS 31, Glomus etunicatum DCS 12, A. delicata DCS 30 e Kuklospora colombiana DCS 03. O incremento na esporulação atingiu 89% e, na colonização, 60%, o que confirma os benefícios da formononetina na colonização e na esporulação dos fungos micorrízicos arbusculares.The aim of this work was to evaluate the effects of Mycoform on both sporulation and colonization of 13 arbuscular mycorrhiza fungi (AMF isolates in Brachiaria decumbens. The experiment was carried out in greenhouse conditions with sterile soil, in a completely randomized design with 3x13 factorial treatments and five repetitions. The product was applied once at planting and was or was not applied a second time 60 days afterwards, at an amount of 2 mg kg-1 of soil. Plants were allowed to grow for 150 days, when root and rhizospheric soil samples were collected to evaluate the percentage of colonized root segments and the spore density. Mycoform

Desempenho de seis gramíneas solteiras ou consorciadas com o Stylosanthes guianensis cv. Mineirão e eucalipto em sistema silvipastoril Performance of six tropical grasses alone or associated with Stylosanthes guianensis cv. Mineirão and eucalypt in silvopastoral system

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Carlos Mauricio Soares de Andrade

2003-12-01

Full Text Available Conduziu-se este estudo na região dos Cerrados de Minas Gerais, visando avaliar o desempenho de seis gramíneas forrageiras (Brachiaria brizantha cv. Marandu, B. brizantha cv. MG-4, B. decumbens cv. Basilisk, Panicum maximum cv. Mombaça, Melinis minutiflora e Hyparrhenia rufa, consorciadas ou não com a leguminosa Stylosanthes guianensis cv. Mineirão e Eucalyptus sp., em um sistema silvipastoril. As forrageiras foram estabelecidas em parcelas medindo 12 x 10 m, nas entrelinhas do eucalipto, em um delineamento experimental de blocos ao acaso, com três repetições, e avaliadas quanto ao grau de cobertura do solo, % de leguminosa e disponibilidade de matéria seca total no sub-bosque, um ano após o estabelecimento, submetidas a pastejos de curta duração. Após dois ciclos de pastejo, houve redução da proporção da leguminosa no consórcio com todas as gramíneas, sendo mais evidente com as mais agressivas (B. brizantha cv. Marandu e B. decumbens, onde ela quase desapareceu. Entretanto, a presença do estilosantes Mineirão favoreceu a produtividade do sub-bosque, quando consorciado com as demais gramíneas. O melhor desempenho produtivo foi obtido pelas gramíneas B. brizantha cv. Marandu, B. decumbens e P. maximum cv. Mombaça; a última principalmente quando consorciada com o estilosantes Mineirão.A study was conducted in the Brazilian Cerrados to evaluate the performance of six tropical forage grasses (Brachiaria brizantha cv. Marandu, B. brizantha cv. MG-4, B. decumbens cv. Basilisk, Panicum maximum cv. Mombaça, Melinis minutiflora and Hyparrhenia rufa, associated or not with the tropical forage legume Stylosanthes guianensis cv. Mineirão, in a silvopastoral system with a clone of Eucalyptus sp. The forages were established in plots of 12 x 10 m, in the interrows of eucalypts, in a randomized block design with three replications. Ground cover, proportion of the legume and total dry matter availability in the understorey were

Signal grass structure at different sites of the same pasture under three grazing intensities - doi: 10.4025/actascianimsci.v35i1.11801

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Ronan Lopes Albino

2013-01-01

Full Text Available The experiment was conducted to evaluate Brachiaria decumbens cv. Basilisk at different sites of the same pasture featuring varying grazing intensities (under grazed, properly grazed and overgrazed. The pasture was managed under continuous stocking using 200-kg cattle and grass height kept at about 25 cm. The randomized block design was used, with three replications. Sward height (38.0 cm and extended plant height (85.2 cm were greater at the under grazed site. The falling index was lower at the properly grazed site (1.28. At the under grazed site, the masses of green leaf blade (3442 kg ha-1 DM, green stem (8370 kg ha-1 DM, green forage (11812 kg ha-1 DM and total forage (14137 kg ha-1 DM were higher when compared to the overgrazed and properly grazed sites. Dead material mass was higher at the properly grazed (3422 kg ha-1 DM and under grazed (2324 kg ha-1 DM sites. At the under grazed sites, there was a higher occurrence of tillers taller than 40 cm. Tillers with sizes between 10 and 30 cm predominated in properly grazed sites. In overgrazed site there was a higher share of tillers with sizes smaller than 20 cm. There is spatial variability of vegetation in the same pasture of Brachiaria decumbens cv. Basilisk due to uneven grazing by cattle.

Crescimento de espécies forrageiras tropicais submetidas a diferentes períodos de alagamento

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Haddade Ismail Ramalho

2002-01-01

Full Text Available O experimento foi realizado no período de janeiro a julho de 1996, com o objetivo de avaliar o crescimento de três espécies forrageiras (Brachiaria decumbens, Brachiaria mutica e Setaria anceps cultivadas em vasos, sob duas situações de manejo (com e sem o corte anterior aos tratamentos e seis diferentes condições (10, 20 e 30 dias, com e sem alagamento. Para as avaliações de crescimento, foram analisadas as produções de matéria seca de folhas, caule e material morto, em dois cortes, referentes ao primeiro crescimento e à rebrota das plantas nos vasos. Durante o período experimental, foram medidos os comprimentos dos perfilhos principais (Oliveira,1989, além do número de folhas presentes, em medições a cada sete dias, em duas plantas por vaso. Os resultados não foram diferentes nas duas situações, encontrando-se algumas diferenças para a S. anceps (espécie cespitosa. A B. mutica foi a espécie mais adaptada, não tendo modificado seu crescimento, mesmo nos maiores períodos de inundação. Essas duas espécies foram superiores à B. decumbens, pouco adaptada às inundações.

DESFOLHAÇÃO DE PERFILHOS EM PASTO DE CAPIM-BRAQUIÁRIA SOB LOTAÇÃO CONTÍNUA

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MANOEL EDUARDO ROZALINO SANTOS

2011-06-01

Full Text Available The objective of this study was to evaluate the number oftillers with different levels of defoliation and theircharacteristics on the Brachiaria decumbens cv. Basilisk pasture. Three different areas on the pasture (undergrazed, with proper grazing and overgrazed and three tiller categories (without defoliation, withdefoliation and without shoot apical meristem were evaluated. Randomized block design with three repetitions was used. The B. decumbens pasture was managed under the continuous stocking system with cattle, and the grass height was kept at about 25cm. Thenumber of tillers showing defoliation was higher (1,333 tillers/m² for the overgrazed area compared to the area with proper grazing and the undergrazed area. Inverse response pattern was observed for the tillers without defoliation. On the other hand, the number of tillerswithout the shoot apical meristem was higher in the areas with proper grazing (395 tillers/m². Tillers without defoliation showed a lower pseudoculm length (10.3cmand a smaller number of dead leaves (0.22 when compared to the other categories. The length of the leafblade did not change for the tiller categories evaluated. The number of grazed leaves was lower for tillers without the shoot apical meristem in relation to the ones showing or not defoliation. Lower leaf area for the tillers that had the shoot apical meristem removed was observed. Tillers without the shoot apical meristem showed a lowerpercentage of green leaf blade (GLB, higher percentages of both live culm (LC and dead leaf blade (DLB as well as a lower relation of the GLB/LC and weight comparing to the tillers showing or not defoliation. Those last ones did not differ regarding their morphological composition. There is indeed spatial variability of the vegetation andtiller diversity with varying levels of defoliation on Brachiaria decumbens cv. Basilisk pastures under continuous grazing.

Evaluación de la degradabilidad in situ en bovinos suplementados con cuatro especies arbóreas

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Roa V, María; Muñoz M, Javier

2012-01-01

Objetivo. Evaluar degradabilidad in situ en rumen de cuatro especies forrajeras: Acacia Roja (Delonix regia), pízamo (Eritryna glauca), Cratilia (Cratylia argentea) y casco de vaca (Bahuinia variegata), para determinar su calidad nutricional. Materiales y métodos. Cuatro hembras rumino-fistuladas en un diseño de sobrecambio simple, pastoreando en Brachiaria decumbens, suplementadas en la mañana con tres kg de hojas deshidratadas de las cuatro especies mencionadas, de un año de establecidas y ...

Primary and secondary metabolites production in signal grass around the year under nitrogen fertilizer

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Syeda Maryam Hussain

2016-01-01

Plants produce a number of substances and products and primary and secondary metabolites (SM) are amongst them with many benefits but limitation as well. Usually, the fodder are not considered toxic to animals or as a source having higher SM. The Brachiaria decumbens has a considerable nutritional value, but it is considered as a toxic grass for causing photosensitization in animals, if the grass is not harvested for more than 30 days or solely. The absence of detailed information in the lite...

Seguimiento a patógenos presentes en biosólido empleado como enmienda para revegetalizar un talud

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López Sánchez, Idalia Jacqueline; Acevedo Cifuentes, Diana Rocío; Ordóñez Ante, Carlos Andrés

2010-01-01

Con el fin de evaluar la factibilidad del uso del biosólido como enmienda orgánica para el establecimiento de vegetación y el control de procesos erosivos superficiales activos, se seleccionó un corte de carretera ubicado sobrela Variante a Caldas (Antioquia). Para darle amarre y cobertura al suelo, se sembraron dos especies vegetales tipo pasto Brachiaria Decumbens y Kikuyo (Pennisetum clandestinum), utilizando biosólido proveniente de la PTAR San Fernando, mezclado con suelo de la zon...

FED INTAKE AND MILK PRODUCTION OF HOLSTEIN-ZEBU CROSSBREED COWS HOLD IN DIFFERENT TROPICAL PASTURES CONSUMO DE ALIMENTOS E PRODUÇÃO DE LEITE DE VACAS MESTIÇAS MANTIDAS EM DIFERENTES PASTAGENS TROPICAIS

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Ana Luiza Costa Cruz Borges

2008-10-01

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Fed intake and milk production of Holstein-Zebu crossbred cows, grazing Napier grass (Pennisetum purpureum (NAP, Brachiaria decumbens (BRA and Guinea grass (Pannicum maximum (COL and supplemented with four kg of concentrate, were evaluated in a double Latin square (3x3. Fecal production and feed intake were calculated using Cr₂O₃ and in vitro digestibility. Dry mater intake (DMI was similar among forages (18kg/cow which represented 2.72%; 2.84% and 2.96% of the live weight for NAP, BRACH and COL respectively. The intake per unit of metabolic size (g DM/kg^0.75 was 130 for NAP, 135 for BRACH and 145 for COL. The intake of BRACH resulted in lower milk production (14,4kg than NAP (15,5kg and COL (16,1Kg. Grasses did not affected the milk composition which showed 4,03% of fat, 2,46% of protein and 12,42% of total solids. It was concluded that NAP, BRACH and COL are good alternatives for milk production in grazing systems.

Crescimento de capim-braquiária influenciado pelo grau de sombreamento e pela estação do ano Growth of signalgrass influenced by shading levels and season of the year

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Domingos Sávio Campos Paciullo

2008-07-01

Full Text Available O objetivo deste trabalho foi avaliar, nas diferentes estações do ano, as características morfogênicas e estruturais e a produção de matéria seca de Brachiaria decumbens Stapf., cultivada em três graus de sombreamento: área de pastagem exclusivamente com B. decumbens, área próxima ao bosque e área com bosque de Eucalyptus grandis consorciado com leguminosas arbóreas (0, 18 e 50% de sombreamento, respectivamente. O delineamento experimental foi o de blocos ao acaso, com arranjo em parcelas subdivididas no tempo, com quatro repetições. O sombreamento induziu à elevação das taxas de alongamento de folhas e colmos. A taxa de aparecimento de folhas e o número de folhas vivas por perfilho não foram influenciados pelos graus de sombreamento. Em geral, no inverno houve redução nos valores das variáveis morfogenéticas e estruturais do dossel, assim como das taxas de produção de forragem, independentemente do sombreamento. A braquiária apresenta plasticidade fenotípica, em resposta às variações climáticas sazonais e aos níveis de sombreamento ambiental, o que confere a essa espécie elevado potencial para uso em sistemas silvipastoris.The objective of this work was to evaluate, in different seasons of the year, the morphogenetic and structural traits and dry matter production of Brachiaria decumbens Stapf., established under three shading conditions: exclusive B. decumbens pasture, area distant 12 m from trees, and area under trees cultivated with Eucalyptus grandis mixed with leguminous trees (0, 18 and 50% shading level, respectively. The experimental design was the randomized blocks, in a split plot array in time, with four replications. Shade caused an increase of leaf and stem elongation rates. Shading levels have not influenced leaf appearance rates and leaf number per tiller. Morphogenetic and structural traits and herbage production rates reduced during winter, independently of shading level. Signalgrass presents

Amazonian açai and food dyes for staining arbuscular- micorrhizal fungi

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Aline Lourdes Martins Silva

2015-12-01

Full Text Available Arbuscular mycorrhizae microscopy requires differential staining of typical structures. Dyes employed, such as trypan blue, pose risks to health and environment. Alternative dyes such as pen ink and aniline have variable coloring efficiency. In this work, Brachiaria decumbens roots, discolored with caustic soda (NaOH, were stained with açai, annatto, saffron, trypan blue and pen inks. There were significant differences among dyes regarding stained mycorrhizal structures and pictures quality. Acai was considered the best alternative dye, with similar results to trypan blue.

Composição química e digestibilidade de fenos tratados com amônia anidra ou uréia Chemical composition and digestibility of the ammoniated hays

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Ricardo Andrade Reis

2001-06-01

Full Text Available O experimento foi conduzido para se avaliarem as alterações na composição química e na digestibilidade in vitro da matéria seca (DIVMS dos fenos de Brachiaria decumbens Stapf, Brachiaria brizantha (Hochst ex. A. Rich Stapf e jaraguá (Hyparrhenia rufa Ness Stapf, colhidos no estádio de maturação das sementes e tratados com amônia anidra (3,0% MS ou uréia (5,4% MS. A análise dos dados demonstra que a amonização diminuiu os conteúdos de FDN e hemicelulose com a mesma eficiência. Os tratamentos químicos não alteraram os teores de FDA, celulose e lignina. Observou-se aumento nos teores de compostos nitrogenados, como N total e N insolúvel em detergente ácido (NIDA em resposta à amonização. A relação NIDA/NT diminuiu com a amonização, aumentando a quantidade de N disponível para a digestão. A DIVMS aumentou em resposta às alterações observadas na composição química da fração fibrosa e incremento no conteúdo de N prontamente digestível dos fenos tratados.The experiment was conducted to evaluate the changes on the chemical composition and in vitro dry matter digestibility (IVDMD of the Brachiaria decumbens Stapf, Brachiaria brizantha (Hochst ex. A. Rich Stapf, jaragua (Hyparrhenia rufa Ness Stapf hays, harvested following the seed ripening stage and treated with anhydrous ammonia (3.0% DM or urea (5.4% DM. The data showed that anhydrous ammonia and urea decreased NDF and hemicellulose contents with the same efficiency. The treatments did not change ADF, cellulose, and lignin contents. It was observed an increase in the nitrogen as compounds, TN and ADIN due to the ammoniation. The ADIN/TN ratio was reduced due to the ammoniation. The IVDMD increased due to the changes observed in the chemical composition of the fiber, and the increase of the readily digestible nitrogen of the hays.

DIGESTIBILIDADE APARENTE DO FENO DE Brachiaria humidicola (Rendle SCHWEICKERDT APÓS A COLHEITA DE SEMENTES APPARENT DIGESTIBILITY OF Brachiaria humidicola (RENDLE SCHWEICKERDT HAY AFTER SEED HARVEST

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Benir de Oliveira

2007-09-01

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Objetivando avaliar a composição química e a digestibilidade aparente de feno de Brachiaria humidicola (Rendle Schweickerdt, após a colheita de sementes, foi realizado um experimento nas dependências do Departamento de Zootecnia da Escola de Veterinária da Universidade Federal de Goiás. Utilizou-se quatro carneiros adultos, castrados, sem raça definida, com bolsas coletoras de fezes e alojados em gaiolas individuais de metabolismo durante 17 dias, sendo 7 de adaptação e 10 de coleta. A digestibilidade aparente da matéria seca (53,64% concorda plenamente com o resultado encontrado "in vitro" (53,37%. Na base de matéria seca, o feno apresentou 53,40% de N.D.T., baixo nível de proteína bruta (3,03% com baixo coeficiente de digestibilidade (11,88%. Nas condições do presente experimento conclui-se que a fenação da Brachiaria humidicola, após a colheita mecânica das sementes, prejudicou o valor nutritivo do feno, principalmente, a proteína bruta e sua digestibilidade.

A trial to study the apparent digestibility of Brachiaria humidicola (Rendle Schweickerdt, grass, was carried out at the Departamento de Zootecnia da Universidade Federal de Goiás. The seeds of B.humidicola have a good commercial value and the farmers utilized a grass of bad quality after mechanical harvest. Four adult lambs, castrated males, of unknown race, were used and placed in metabolical individual cages during 17 days, 7 for adaptation and 10 for collection period. The apparent digestibility of dry matter was 53.64% and ";in vitro"; 53.37%. On dry matter-basis the hay has 53.40% of TND value, a poor crude protein (3.03% value with low coefficient of digestibility (11 .88%.

Efficacy of oxyfluorfen with straw cover in controlling weeds

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Negrisoli, E. [UNESP; Correa, M. R. [UNESP; Rossi, C. V. S. [UNESP; Carbonari, Caio Antonio [UNESP; Velini, Edivaldo Domingues [UNESP; Perim, L. [UNESP

2009-01-01

A palha pode alterar a dinâmica do herbicida oxyfluorfen no sistema de cana-crua; assim, este trabalho teve por objetivo avaliar a eficácia do oxyfluorfen em condições de casa de vegetação, com a cobertura de palha, no controle das plantas daninhas que ocorrem em cana-crua. Foram avaliadas as espécies de Brachiaria decumbens, Ipomoea grandifolia, Ipomoea quamoclit e Merremia cissoides. A dose utilizada do oxyfluorfen foi de 3 L ha-1 (720 g i.a. ha-1). Os tratamentos constaram de diferentes po...

Comparaison du Pangola (Digitaria decumbens) et du Stargrass (Cynodon nlemfluensis) exploités par des ovins

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Boval, Maryline

1989-01-01

A la Martinique l'utilisation comparée de Digitaria decumbens (Dd) et de Cynodon nlemfuensis (Cn) par des brebis allaitantes a été étudiée pendant une période d'observation de 6 mois. Le cheptel est à un taux élevé de 1 600 kg de poids vif par hectare et par an, obtenu par une fertilisation de 450 kg/ha/an en azote.

Características morfogênicas e estruturais de perfilhos de capim-braquiária em locais do pasto com alturas variáveis Morphogenic and structural characteristics of tillers on areas with signalgrass pasture varying on height

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Manoel Eduardo Rozalino Santos

2011-03-01

Full Text Available O experimento foi conduzido com o objetivo de avaliar a influência das variações naturais da altura da planta no mesmo pasto sobre as características morfogênicas e estruturais da Brachiaria decumbens cv. Basilisk manejada sob lotação contínua com bovinos. Foram avaliadas quatro alturas de plantas (10, 20, 30 e 40 cm no mesmo pasto manejado com altura média de 25 cm. Adotou-se o delineamento em blocos ao acaso com duas repetições. A taxa de aparecimento foliar do capim-braquiária foi influenciada linear e negativamente pelas alturas das plantas no mesmo pasto. Os perfilhos presentes nos locais com maior altura apresentaram maior filocrono (9,3 dias. A maior altura das plantas no mesmo pasto promoveu maiores taxas de senescência foliar e de alongamento de pseudocolmo no perfilho. A duração de vida da folha (37,8 dias e a taxa de alongamento foliar (1,3 cm/perfilho.dia não foram influenciadas pela altura da planta. Os números de folhas vivas (4,36 e mortas (2,15 também não foram modificados pela altura da planta. Já a maior altura das plantas resultou em aumento linear de 69% no número de folhas com desfolhação. Os comprimentos do pseudocolmo e da lâmina foliar responderam linear e positivamente ao aumento na altura da planta no mesmo pasto. A variação natural na altura da planta no mesmo pasto altera as características morfogênicas e estruturais do capim-braquiária. Existe variabilidade espacial da vegetação em pastos de Brachiaria decumbens cv. Basilisk manejados sob lotação contínua com bovinos.The objective of this experiment was to evaluate the influence of natural variation of heights of plants on the same pasture on the morphogenic and structural characteristics of Brachiaria decumbens cv. Basilisk managed under continuous stocking with cattle. Four plant heights (10, 20, 30 and 40 cm were evaluated on the same pasture managed at an average height of 25 cm. It was used a randomized block design with two

Silicon as an attenuator of salt stress in Brachiaria brizantha ‘MG5’

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Maria Isabel Leite da Silva

Full Text Available ABSTRACT The aim of this study was to evaluate the effect of salt stress and silicon fertiliser on growth and nutritional value in Brachiaria brizantha ‘MG5’. The experimental design was completely randomised in a 4 x 5 x 3 factorial scheme with four replications; the treatments consisted of four concentrations of sodium chloride (0, 20, 40 and 60 mmol L-1, with five concentrations of silicon (0, 1, 2, 3 and 4 mmol L-1 in the nutrient solution, and three cutting periods (30, 60 and 90 days. The concentration of 4 mmol L-1 silicon minimised the detrimental effects of the sodium chloride on regrowth. However, the levels of silicon application were not sufficient to reduce the harmful effects of the sodium chloride on nutritional value or on dry-matter production in Brachiaria brizantha ‘MG5’.

Histogram score contributes for reliability of DNA content estimatives in Brachiaria spp Notas do histograma contribuem para a confiabilidade das estimativas do conteúdo de DNA de Brachiaria spp

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Ana Luiza de Oliveira Timbó

2012-12-01

Full Text Available Flow cytometry allows to estimate the DNA content of a large number of plants quickly. However, inadequate protocols can compromise the reliability of these estimates leading to variations in the values of DNA content the same species. The objective of this study was to propose an efficient protocol to estimate the DNA content of Brachiaria spp. genotypes with different ploidy levels using flow cytometry. We evaluated four genotypes (B. ruziziensis diploid and artificially tetraploidized; a tetraploid B. brizantha and a natural triploid hybrid, three buffer solutions (MgSO4, Galbraith and Tris-HCl and three species as internal reference standards (Raphanus sativus, Solanum lycopersicum e Pisum sativum. The variables measured were: histogram score (1-5, coefficient of variation and estimation of DNA content. The best combination for the analysis of Brachiaria spp. DNA content was the use of MgSO4 buffer with R. sativus as a internal reference standard. Genome sizes expressed in picograms of DNA are presented for all genotypes and the importance of the histogram score on the results reliability of DNA content analyses were discussed.A citometria de fluxo permite estimar o conteúdo de DNA de um grande número de plantas rapidamente. No entanto, protocolos inadequados podem comprometer a confiabilidade dessas estimativas, levando a variações nos valores de conteúdo de DNA para uma mesma espécie. Neste trabalho, objetivou-se propor um protocolo eficiente para a estimativa do conteúdo de DNA de genótipos de Brachiaria spp. com diferentes níveis de ploidia, utilizando a citometria de fluxo. Foram avaliados quatro genótipos (B. ruziziensis, diploide e tetraploidizada artificialmente; B. brizantha tetraploide e um híbrido natural triploide, 3 soluções tampões (MgSO4, Galbraith e Tris-HCl e três espécies como padrões de referência interno (Raphanus sativus, Solanum lycopersicum e Pisum sativum. As variáveis mensuradas foram: nota do

Enrichment of arbuscular mycorrhizal fungi in a contaminated soil after rehabilitation.

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Lopes Leal, Patrícia; Varón-López, Maryeimy; Gonçalves de Oliveira Prado, Isabelle; Valentim Dos Santos, Jessé; Fonsêca Sousa Soares, Cláudio Roberto; Siqueira, José Oswaldo; de Souza Moreira, Fatima Maria

Spore counts, species composition and richness of arbuscular mycorrhizal fungi, and soil glomalin contents were evaluated in a soil contaminated with Zn, Cu, Cd and Pb after rehabilitation by partial replacement of the contaminated soil with non-contaminated soil, and by Eucalyptus camaldulensis planting with and without Brachiaria decumbens sowing. These rehabilitation procedures were compared with soils from contaminated non-rehabilitated area and non-contaminated adjacent soils. Arbuscular mycorrhizal fungi communities attributes were assessed by direct field sampling, trap culture technique, and by glomalin contents estimate. Arbuscular mycorrhizal fungi was markedly favored by rehabilitation, and a total of 15 arbuscular mycorrhizal fungi morphotypes were detected in the studied area. Species from the Glomus and Acaulospora genera were the most common mycorrhizal fungi. Number of spores was increased by as much as 300-fold, and species richness almost doubled in areas rehabilitated by planting Eucalyptus in rows and sowing B. decumbens in inter-rows. Contents of heavy metals in the soil were negatively correlated with both species richness and glomalin contents. Introduction of B. decumbens together with Eucalyptus causes enrichment of arbuscular mycorrhizal fungi species and a more balanced community of arbuscular mycorrhizal fungi spores in contaminated soil. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

[Pharmacokinetics of 8-O-acetylharpagide and harpagide after oral administration of Ajuga decumbens extract in beagle dog].

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Wen, Bin-Yu; Li, Jian-Rong

2013-06-01

8-O-acetylharpagide and harpagide are two kinds of effective component of Ajuga decumbens extract. A sensitive LC-MS/MS method has been established for pharmacokinetics of 8-O-acetylharpagide and harpagide in beagle dog after oral administration of from A. decumbens extract. Female beagle dogs received orally 12.9, 25.7 mg x kg(-1) p. o. Concentrations of 8-O-acetylharpagide and harpagide in plasma were determined by LC-MS/MS method at different time points and all pharmacokinetic parameters were estimated by non-compartment analysis. The mobile phase consisted of 0.1% formic acid in water (A) and acetonitrile (B), which was run at a flow rate of 0.3 mL x min(-1). Chromatographic separation was achieved on an Agilent ZORBAX XDB-C18 column (2.1 mm x 50 mm, 3.5 microm) using a gradient elution of 5% B at 0-2 min, 95% B at 2. 1-5 min and 5% B at 5. 1-10 min. All analytes, including the IS, were monitored under positive ionization conditions and quantified in MRM mode with transitions of m/z 429.2-369.2 for 8-O-acetylharpagide, m/z 387.2-207.2 for harpagide, and m/z 149.2-103.1 for IS. High purity nitrogen was employed as both the nebulizing and drying gas. Other parameters of the mass spectrometer were optimized as follows: drying gas flow 10.0 L x min(-1); drying gas temperature 300 degrees C; capillary voltage 4 000 V. Results showed that 8-O-acetylharpagide and harpagide showed a dose-dependence profile. T(max) of 8-O-acetylharpagide is 1.7 h, and T(max) of harpagide is 1.57 h, which was higher than T(max) of 8-O-acetylharpagide and harpagide after oral administration of from A. decumbens extract in rats. The different pharmacokinetic parameters may be due to the species differences of rat and beagle dog.

Estrutura do capim-braquiária durante o diferimento da pastagem - doi: 10.4025/actascianimsci.v32i2.7922 Signalgrass structure during pasture deferment - doi: 10.4025/actascianimsci.v32i2.7922

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Marcela Azevedo Magalhães

2010-07-01

Full Text Available O experimento foi realizado para avaliar o número de perfilhos, a massa de forragem e de seus componentes morfológicos em pastos de Brachiaria decumbens cv. Basilisk durante o diferimento da pastagem. Os tratamentos foram quatro períodos de diferimento (18, 46, 74 e 121 dias, a partir de 8/3/2004. O delineamento foi em blocos casualizados com duas repetições. Foram determinados os números de perfilhos vegetativos (PV, reprodutivos (PR e mortos (PM, bem como as massas de lâmina foliar verde (MLV, colmo verde (MCV e forragem morta (MFM. Durante o período de diferimento houve redução no número de PV (de 1.491 para 944 perfilhos m-2. Os números de PR e PM não foram influenciados pelo período de diferimento e suas médias foram 211 e 456 perfilhos m-2, respectivamente. O período de diferimento causou incremento nas MCV (de 2.965 para 4.877 kg ha-1 de massa seca e MFM (2.324 para 4.823 kg ha-1 de massa seca, porém não influenciou a MLV (em média, 2.047 kg ha-1 de massa seca. Em Viçosa, Estado de Minas Gerais, o pasto de B. decumbens, adubado com nitrogênio e diferido no início de março, pode permanecer diferido por cerca de 70 dias para conciliar produção de forragem em quantidade com boa composição morfológica.This experiment was performed aiming to evaluate tiller population density, forage mass and its morphological components on pastures of Brachiaria decumbens cv. Basilisk. during deferment. The treatments encompassed four deferred grazing periods (18, 46, 74 and 121 days. A randomized block design with two replications was used. The numbers of vegetative tillers (VT, reproductive tillers (RT and dead tillers (DT in the pasture were determined. The masses of green leaf blade (GLBM, dead stem (DSM and dead forage (DFM were also determined. There was a reduction in the number of VT (from 1,491 to 944 tiller m-2 during the deferment period. RT and DT numbers were not influenced by the deferment periods. Their averages were

Estrutura do capim-braquiária durante o diferimento da pastagem = Signalgrass structure during pasture deferment

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Manoel Eduardo Rozalino Santos

2010-04-01

Full Text Available O experimento foi realizado para avaliar o número de perfilhos, a massa de forragem e de seus componentes morfológicos em pastos de Brachiaria decumbens cv. Basilisk durante o diferimento da pastagem. Os tratamentos foram quatro períodos de diferimento (18, 46, 74 e 121dias, a partir de 8/3/2004. O delineamento foi em blocos casualizados com duas repetições. Foram determinados os números de perfilhos vegetativos (PV, reprodutivos (PR e mortos (PM, bem como as massas de lâmina foliar verde (MLV, colmo verde (MCV e forragemmorta (MFM. Durante o período de diferimento houve redução no número de PV (de 1.491 para 944 perfilhos m-2. Os números de PR e PM não foram influenciados pelo período de diferimento e suas médias foram 211 e 456 perfilhos m-2, respectivamente. O período de diferimento causou incremento nas MCV (de 2.965 para 4.877 kg ha-1 de massa seca e MFM (2.324 para 4.823 kg ha-1 de massa seca, porém não influenciou a MLV (em média, 2.047 kg ha-1 de massa seca. Em Viçosa, Estado de Minas Gerais, o pasto de B. decumbens, adubado com nitrogênio e diferido no início de março, pode permanecer diferido por cerca de 70 dias para conciliar produção de forragem em quantidade com boa composição morfológica. This experiment was performed aiming to evaluate tiller population density, forage mass and its morphological components on pastures of Brachiaria decumbens cv. Basilisk. during deferment. The treatments encompassed four deferred grazing periods (18, 46, 74 and 121 days. Arandomized block design with two replications was used. The numbers of vegetative tillers (VT, reproductive tillers (RT and dead tillers (DT in the pasture were determined. The masses of green leaf blade (GLBM, dead stem (DSM and dead forage (DFM were alsodetermined. There was a reduction in the number of VT (from 1,491 to 944 tiller m-2 during the deferment period. RT and DT numbers were not influenced by the deferment periods. Their averages were

Leguminosas arbóreas introduzidas em pastagem Performance of leguminous trees introduced into pastures

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Paulo Francisco Dias

2007-01-01

Full Text Available O objetivo deste trabalho foi analisar, por meio de métodos de análise de variância multivariada, o comportamento de 16 espécies de leguminosas arbóreas, introduzidas em pastagem estabelecida de Brachiaria decumbens, a partir de mudas pequenas e em presença de animais, em quatro épocas do ano, em Seropédica, RJ. Nove variáveis relacionadas ao comprimento e ao número de brotos das mudas, antes e após o pastejo dos animais, foram utilizadas nas avaliações. As diferenças estatísticas entre as médias da variável canônica principal, pelo teste de Scott-Knott, indicaram a formação de quatro agrupamentos, tendo-se destacado o grupo formado pelos tratamentos Mimosa tenuiflora nas 3ª e 4ª avaliações. Diferenças entre as médias dos tratamentos, para cada variável, calculadas por meio de intervalos de confiança de Bonferroni, mostraram que o maior comprimento e o maior número de brotos na muda, após o pastejo, foram encontrados na M. tenuiflora. Esta leguminosa é indicada para ser introduzida, com maior probabilidade de sucesso, nas pastagens de B. decumbens na região, sem a proteção das mudas e em presença de gado.The objective of this work was to analyse, by means of multivariate variance analysis, the behaviour of 16 leguminous tree species introduced into pastures of Brachiaria decumbens from unprotected young plants and under grazing, in four periods of the year, in Seropédica, RJ, Brazil. Nine variables, related to length and to number of sprouting, before and after animal grazing, were used for the evaluation. The statistical difference of the means of the principal canonical variable, calculated by the Scott-Knott test, indicated the formation of four groups, and the Mimosa tenuiflora group stood out at the 3rd and 4th evaluations. Difference among treatment means for each variable, calculated by Bonferroni confidence intervals, showed that the greatest sprouting length and the highest number of sprouting, after

Influência do período de restrição hídrica na atividade residual de isoxaflutole no solo Influence of drought periods on the residual activity of isoxaflutole in soil

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R.S. Oliveira Jr.

2006-12-01

Full Text Available O objetivo deste trabalho foi estudar a atividade residual do isoxaflutole (IFT no controle de Brachiaria decumbens sob diferentes períodos de seca, após a aplicação do herbicida, em dois solos. Para isso, foram realizados seis ensaios simultâneos, sendo utilizadas doses de 0, 230 e 270 g ha-1 de isoxaflutole em amostras de Latossolo Vermelho Distroférrico nitossólico (textura argilosa e doses de 0, 180 e 200 g ha-1 em amostras de Latossolo Vermelho distrófico (textura franco-argilo-arenosa. Em cada ensaio, foram combinados em esquema fatorial doses e períodos de seca após as aplicações do herbicida, utilizando-se B. decumbens como bioindicador da atividade residual do herbicida no solo. As avaliações de controle foram feitas aos 15, 30, 45 e 60 dias após a semeadura do bioindicador. O IFT apresentou alta estabilidade no solo de textura argilosa mesmo após três chuvas simuladas de 20 mm, espaçadas de 30 dias e seguidas de 120 dias de seca após sua aplicação. No solo de textura franco-arenosa a estabilidade foi menor, e o efeito residual (80% de controle persistiu entre 0 e 110 dias para B. decumbens, conforme dose, períodos de seca e data de avaliação após a semeadura. Esse fato evidenciou que, à medida que aumenta o tempo e o número de irrigações entre a aplicação do herbicida e a semeadura do bioindicador, há redução no potencial efetivo de controle de IFT no Latossolo Vermelho distrófico.This work was carried out to evaluate the residual activity of isoxaflutole (IFT in Brachiaria decumbens control after different simulated drought conditions following herbicide application in two soils. Six simultaneous experiments were performed, using rates of 0, 230 and 270 g ha-1 of IFT in samples of a heavy clay soil and of 0, 180 and 200 g ha-1 in samples of a sandy clay loam soil. In each experiment, rates of IFT were combined in a factorial scheme with drought periods after herbicide application. B. decumbens was

Análise do crescimento de uma cultivar de braquiária em cultivo solteiro e consorciado com cereais Growth analysis of a brachiaria cultivar sole and intercropped with cereals

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TOMÁS DE AQUINO PORTES

2000-07-01

Full Text Available O objetivo deste trabalho foi avaliar o crescimento de braquiária (Brachiaria brizantha cv. Marandu, em consorciação com milho, sorgo, milheto e arroz, bem como da sua rebrota após a colheita dos cereais. A presença dos cereais provocou redução no número de perfilhos, índice de área foliar, massa seca total da parte aérea, massa seca das folhas verdes e dos colmos e taxa de crescimento na braquiária, até a colheita dos cereais. O número de perfilhos alcançou valores maiores do que os da braquiária solteira, após a colheita dos cereais. Os índices de área foliar da braquiária consorciada foram baixos, em comparação com os dos cereais, e a baixa competição, em cobertura foliar, favoreceu a boa produtividade de grãos das culturas. Aos 60-70 dias após a colheita dos cereais, a braquiária rebrotada possuía fitomassa semelhante à da solteira 70 dias após a emergência.The aim of this work was to evaluate the growth of brachiaria (Brachiaria brizantha cv. Marandu intercropped with maize, sorghum, pearl millet and rice and its regrowth after cereals harvest. The presence of cereals caused reduction of tillers number, foliar area index, total dry matter of leaves, dry matter of green leaves and stems, and growth rate of brachiaria up to harvest of cereals. Number of tillers m-2 reached higher values than those of sole cropped brachiaria after the cereals harvest. The leaf area indices of intercropped brachiaria were low, when compared to those of the cereals; and the low competition in the leaf area favoured the good grain yield of the crops. Sixty to seventy days after cereals harvest, brachiaria regrowth showed phytomass similar to that of sole cropped brachiaria 70 days after emergence.

Nitrogen balance in grasses of the genus Brachiaria

International Nuclear Information System (INIS)

Loureiro, M. de F.

1985-01-01

A 15 N aided nitrogen balance experiment was performed in posts in the greenhouse to quantify the contribution of biological nitrogen fixation to four species of Brachiaria grow in two soils. The effects of adding molybdenum to the pots was also investigated. Among various methods for the analysis of total nitrogen in plant material and soil, a technique utilizing a pre-digestion with Devarda's alloy was found to be most efficient. In the nitrogen analyses the sample size and particle size were found to be factors limiting the precision of the analyses. In an analysis of the sources of error, the sampling of the soil was found to be the greatest source of variation on the nitrogen balance. (author)

Fungos e nematoides associados a sementes de forrageiras tropicais

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Guilherme Mallmann

2013-09-01

Full Text Available Objetivou-se avaliar a incidência de fungos e nematoides em sementes de Brachiaria sp. e Panicum maximum produzidas nos estados de Mato Grosso do Sul (MS, Mato Grosso (MT, Goiás (GO, Minas Gerais (MG e São Paulo (SP. Os principais fungos encontrados nas sementes foram Bipolaris sp., Curvularia sp. e Phoma sp.. As menores incidências destes fungos foram encontradas nas sementes das cultivares BRS Piatã e Xaraés de Brachiaria brizantha e Brachiaria decumbens cv. Basilisk, oriundas dos estados de GO, MG e MS, respectivamente. As cultivares Marandu e BRS Piatã, provenientes das várias regiões, apresentaram elevada ocorrência de Aphelenchoides sp. e Ditylenchus sp.. Sementes da cultivar Humidicola, de Brachiaria humidicola, produzidas em MS e SP, não apresentaram associação com nematoides. As sementes de Panicum maximum cv. Massai e cv. Mombaça apresentaram maiores incidências de Bipolaris sp., Cladosporium sp., Curvularia sp., Fusarium sp. e Phoma sp., bem como de Aphelenchoides sp. e Ditylenchus sp., especialmente nas sementes produzidas em MT. Alguns dos patógenos encontrados são agentes causais de doenças de grande importância em forrageiras, a exemplo de Bipolaris sp., causando a mancha foliar do Panicum, de alta severidade em Tanzânia, proporcionando sérios comprometimentos da sustentabilidade das pastagens.

IMPACT OF BRACHIARIA, ARBUSCULAR MYCORRHIZA, AND POTASSIUM ENRICHED RICE STRAW COMPOST ON ALUMINIUM, POTASSIUM AND STABILITY OF ACID SOIL AGGREGATES

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Bariot Hafif

2013-04-01

Full Text Available Acid soil is commonly grown with cassava, which in general, tolerate low soil  fertility and aluminum (Al toxicity. However, without any improvement efforts such soil will become worse. Intercropping cassava with Brachiaria decumbens (BD which adapts to acid soil and tolerates low fertility soils as well as application of arbuscular mycorrhiza (AM and organic matters are among the important efforts to rehabilitate this soil. The experiment was conducted to  examine the impact of BD, AM, and potassium (K enriched rice straw compost on exchangeable Al, available K, and stability of soil aggregates. Experiment was arranged in a completely randomized design with three factors and three replications. The first factor was BD as cassava intercropping, the second factor was AM, and the third factor was 2 t ha-1 rice straw compost enriched with 0 kg, 50 kg, 100 kg, and 200 kg KCl ha-1. Brick pots (1 m length x 1 m width x 0.45 m depth filled with Kanhapludult soil was used for growing cassava in which row of BD was planted at 60 cm from cassava stem. K-enriched rice straw compost and AM (10 g per stem were applied around cassava stem at 2 and 12 days after planting, respectively. BD was cut every 30 days and the cutting was returned to the soil. Soil exchangeable Al was analyzed at 0, 3, 6 and 9 months after planting (MAP, while Al and K contents as well as aggregate stability were measured at 6 MAP. The results showed that planting BD decreased 33% exchangeable Al, which means that the root exudates of this grass was effective in detoxifying Al3+. Treatment of BD and/or in combination with AM was effective in preserving K added to the soil, increasing total polysaccharides, and improving soil aggregate stability. This indicated that planting BD and applying AM and Kenriched rice straw compost improved acid soil fertility, and therefore can be recommended in cassava cultivation.

DETERMINATION OF THE TOXIC EFFECTS OF MERCURY IN THE Brachiaria dictyoneura (Fig. & De Not. Stapf SPECIES

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Gladis E. Morales

2013-03-01

Full Text Available In this research has been evaluated, on a laboratory scale, the toxic effect of mercury on the root development and biomass growth of the Brachiaria dictyoneura species, with the goal of finding an adequate concentration interval for the study on the accumulation of Hg (II. Brachiaria dictyoneura seeds were exposed to different amounts of mercury, the germination kinetics were determined, and after a 20 day growth period the length of the roots and the biomass were measured. There were found harmful effects on the root development starting at 25 mg*kg-1 Hg (II; for the dry biomass the differences were found starting at 5 mg*kg-1 Hg (II and starting at 75 mg*kg-1 Hg (II for the seed emergency time, therefore, working with concentrations not exceeding 25 mg Hg(II*kg-1 of substrate is suggested.

Rendimento e composição química do capim-braquiária introduzido em pastagem degradada de capim-gordura Yield and chemical-proximal composition of signalgrass established on a degraded molassesgrass pasture

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Cláudio Manoel Teixeira Vitor

2008-12-01

Full Text Available Um experimento foi conduzido para avaliação de uma pastagem de capim-gordura (Melinis minutiflora, Beauv. degradada, renovada por meio da introdução de capim-braquiária (Brachiaria decumbens, Stapf em consórcio com estilosantes (Stylosanthes guianensis, cv. Mineirão e da adubação com nitrogênio (0, 50, 100 e 150 kg/ha.ano. O delineamento experimental foi de blocos ao acaso com três repetições. A pastagem foi avaliada em um período seco com um único corte e em um período chuvoso com três cortes. A adubação nitrogenada aumentou a produção de massa seca (MS e o teor de proteína bruta (PB do capim-braquiária, tanto no período seco quanto no chuvoso. Os teores de fibra em detergente neutro (FDN e de fibra em detergente ácido (FDA não foram influenciados pelas doses de nitrogênio em nenhum dos períodos avaliados. Nas maiores doses de nitrogênio, os teores de fósforo, cálcio e magnésio não se alteraram no período seco nem no chuvoso, enquanto os teores de potássio diminuíram em ambos os períodos. A produção de MS no consórcio de capim-braquiária com o estilosantes foi similar à obtida com o capim-braquiária sem adubação nitrogenada no período seco e não diferiu estatisticamente da produção observada com adubação nitrogenada no período chuvoso. Em geral, o teor de proteína bruta da forragem do consórcio foi maior que o da gramínea pura adubada com nitrogênio.An experiment was carried out to evaluate the reclamation of a degraded pasture of molassesgrass (Melinis minutiflora, Beauv., with the establishment of signalgrass (Brachiaria decumbens, Stapf, with different N doses (0, 50, 100, and 150 kg/ha.year or in consortium with S. guianensis cv. mineirão, in a complete randomized blocks design, with three replications per treatment. Evaluations were performed during the dry season (one evaluation and wet season (three evaluations. Nitrogen fertilization promoted increment in dry matter production and

NUTRITIVE QUALITY OF TEN GRASSES DURING THE RAINY SEASON IN A HOT-HUMID CLIMATE AND ULTISOL SOIL

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Rodrigo Ortega-Gómez

2011-11-01

Full Text Available The nutritive quality of ten grasses harvested at 3, 6, 9 and 12 weeks of regrowth was assessed during the rainy season (August-October 2008, in the humid tropics of Veracruz, Mexico. Grasses tested included four Brachiaria spp.: “insurgente”–B. brizantha, “signal”–B. decumbens, Chetumal–B. humidicola, “mulato I”–B. brizantha x B. ruziziensis; three Panicum maximum: Mombasa, “privilegio”, Tanzania; and three Pennisetum spp.: Taiwán, and the hybrids P. purpureum x P. glaucum “Cuban” king grass and “purple” king grass. Means for crude protein by grass group were: Pennisetum spp. (9.9 % = P. maximum (8.7 % > Brachiaria spp. (7.6 %, whereas means for in situ dry matter disappearance (ISD were: Pennisetum spp. (69.7 % > Brachiaria spp. (65.1 % > P. maximum (59.7 %. Crude protein and ISD significantly decreased by 0.42 % and 1.50 % per week. Neutral detergent fiber was not affected by model effects (mean 71.4 %. Means for acid detergent fiber (ADF by grass group were: P. maximum (47.6 % = Pennisetum spp. (44.0 % > Brachiaria spp. (42.8 %, whereas means for lignin (LIG were: P. maximum (8.5 % > Pennisetum spp. (7.6 % > Brachiaria spp. (6.7 %. The ADF and LIG significantly increased by 1.21 % and 0.19 % per week. Pennisetum spp. had the highest nutritive value at all regrowth ages.

Does crotalaria (Crotalaria breviflora or pumpkin (Cucurbita moschata inter-row cultivation in restoration plantings control invasive grasses?

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Ricardo Gomes César

2013-08-01

Full Text Available Alternative methods to control invasive fodder grasses are necessary to reduce the use of herbicides in forest restoration, which has been carried out primarily in riparian zones. We sought to investigate if inter-row cultivation of crotalaria (Crotalaria breviflora DC or pumpkin (Cucurbita moschata Duschene ex. Poir with native tree species is an efficient strategy to control invasive fodder grasses in restoration plantings. We tested five treatments in a randomized block design, namely (1 control of brachiaria grass (Urochloa decumbens (Stapf. Webster with glyphosate in the implementation and post-planting grass control of the reforestation, (2 and 3 glyphosate use in the implementation and inter-row sowing of crotalaria (2 or pumpkin (3, and control of brachiaria by mowing in the post-planting phase, (4 and 5 mowing in the implementation and inter-row sowing of crotalaria (4 or pumpkin (5, and control of brachiaria by mowing in the post-planting phase. Post-planting grass control was carried out four and nine months after tree seedling planting. Throughout 13 months, we evaluated the percentage of ground cover by brachiaria grass, pumpkin production, and native tree seedling mortality, height and crown cover. The exclusive use of glyphosate, without inter-row sowing of pumpkin or crotalaria showed the most favorable results for controlling brachiaria grass and, consequently, for tree seedling development. Hence, inter-row cultivation of green manure or short-lived crop species is not enough to control invasive grasses in restoration plantings, and complementary weeding is necessary to reduce the highly competitive potential of C4 grasses for supporting native species seedlings growth.

Beneficial use of industrial by-products for phytoremediation of an arsenic-rich soil from a gold mining area.

Science.gov (United States)

Lopes, G; Ferreira, P A A; Pereira, F G; Curi, N; Rangel, W M; Guilherme, L R G

2016-08-02

This study investigated two industrial by-products - red mud (RM) and its mixture with phosphogypsum (RMG), as amendments in an As((5+))-contaminated soil from a gold mining area in Brazil in order to grow three plant species: Brachiaria decumbens, Crotalaria spectabilis, and Stylosanthes cv. Campo Grande. These amendments were applied to reach a soil pH of 6.0. Using RM and RMG increased shoot dry matter (SDM) and root dry matter (RDM) of most plants, with RMG being more effective. Adding RMG increased the SDM of Brachiaria and Crotalaria by 18 and 25% and the RDM by 25 and 12%, respectively. Stylosanthes was sensitive to As toxicity and grew poorly in all treatments. Arsenic concentration in shoots of Brachiaria and Crotalaria decreased by 26% with the use of RMG while As in roots reduced by 11 and 30%, respectively. Also, the activities of the plant oxidative stress enzymes varied following treatments with the by-products. The plants grew in the As-contaminated soil from the gold mining area. Thus, they might be employed for phytoremediation purposes, especially with the use of RMG due to its potential advantage in terms of nutrient supply (Ca(2+) and SO4(2-) from phosphogypsum).

Correspondence analysis evaluation of linear nutrient distribution in root tips of the tropical forage Brachiaria brizantha

International Nuclear Information System (INIS)

Pineda-Vargas, C.A.; Prozesky, V.M.; Przybylowicz, W.J.; Mayer, J.E.

2001-01-01

The technique of correspondence analysis was applied to a set of data obtained from X-ray elemental analysis by nuclear microscopy. Hydroponic experiments simulating tropical acid soil conditions were carried out to determine possible mechanisms of Al-toxicity stress on specific varieties of the genus Brachiaria. In particular the species Brachiaria brizantha was tested for gradient variation along the central cylinder of selected root tips. Single-point irradiations by nuclear microscopy gave some indication of a possible trace element profile gradient along the root axis. To be able to extrapolate the possible correlation and trace elemental concentrations gradients to a more confident level, this nuclear microscopy data obtained was analysed by correspondence analysis. A clear gradient on the plot of the first two axes of the correspondence analysis was found. The correlation of Ca and Cu as well as that of K and Cl were established

Fotossensibilização hepatógena em eqüinos pela ingestão de Brachiaria humidicola (Gramineae no Estado do Pará Hepatogenous photosensitization in horses caused by Brachiaria humidicola (Gramineae in the State of Pará

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José Diomedes Barbosa

2006-09-01

Full Text Available São apresentados os aspectos clínico-patológicos e epidemiológicos de doença, caracterizada por fotossensibili-zação, que ocorre em eqüinos no nordeste do Estado do Pará. De um total de 40 animais examinados clinicamente, sete foram necropsiados, e tiveram fragmentos de órgãos examinados microscopicamente. Em virtude das lesões características encontradas, sobretudo nas partes despigmentadas da pele, das le-sões hepáticas macro e microscópicas, e sabendo-se que as brachiárias, de uma maneira geral, encerram saponinas com propriedades tóxicas, que causam alterações hepáticas e fo-tossensibilização em bovinos e ovinos, conclui-se, que essa doença fotossensibilizante foi determinada pelo pastoreio de Brachiaria humidicola, alimentação exclusiva dos animais enfermos.Data on the clinical-pathological aspects and on the epidemioloy of a disease in horses, characterized by phototsensitization, which occurs in northeastern of Pará, Brazil, are presented. Of a total of 40 horses examined clinically, post-mortem examination was performed on seven. Due to the characteristic lesions found on the non-pigmented skin, the macroscopic and histological alterations in the liver, and knowing that Brachiaria grasses contain saponins with toxic properties, which cause liver lesions and photosensitization in cattle and sheep, it is concluded that this disease in horses is caused by grassing exclusively Brachiaria humidicola.

Características morfológicas, estruturais e produtividade do capim-braquiária e do amendoim forrageiro submetidos ao sombreamento Morphological and structural characteristics and productivity of Brachiaria grass and forage peanut submitted to shading

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Kátia Fernanda Gobbi

2009-09-01

Full Text Available As características morfológicas, estruturais e a produção de matéria seca (PMS do capim-braquiária (Brachiaria decumbens, cv. Basilisk e do amendoim forrageiro (Arachis pintoi, cv. Amarillo foram avaliadas em resposta a três níveis de sombreamento artificial (0, 50 e 70%. Utilizou-se o delineamento em blocos casualizados, com três repetições. Foram realizados três e dois cortes, respectivamente, para avaliação do capim-braquiária e do amendoim forrageiro. O amendoim forrageiro apresentou redução significativa na produção de matéria seca com o sombreamento apenas no segundo corte. A produção de matéria seca no capim-braquiária diminuiu linearmente nos dois primeiros cortes. O sombreamento crescente estimulou o aumento da altura média do dossel e do comprimento de pecíolos, colmos e lâminas foliares em todos os cortes das espécies avaliadas. O sombreamento promoveu diminuição linear da densidade populacional de perfilhos no dossel de braquiária em todos os cortes. O peso médio dos perfilhos, no entanto, só foi afetado no terceiro corte, quando aumentou de forma linear de acordo com os níveis de sombreamento. A relação folha:caule da gramínea e da leguminosa não foi afetada pelo sombreamento. A área foliar específica, a área foliar por folíolo e a área foliar por perfilho aumentaram significativamente com o aumento dos níveis de sombreamento. O índice de área foliar (IAF reduziu de forma linear no segundo corte com o sombreamento do amendoim forrageiro e do capim-braquiária. O amendoim forrageiro e o capim-braquiária são forrageiras com bom potencial para avaliação e uso em sistemas silvipastoris com transmissão luminosa em torno de 50% da radiação fotossinteticamente ativa.The morphological and structural characteristics and dry matter production of signalgrass (Brachiaria decumbens, cv. Basilisk and forage peanut (Arachis pintoi, cv. Amarillo were evaluated in response to different shading

Fertilização com N e S na recuperação de pastagem de Brachiaria brizantha cv. Marandu em neossolo quartzarênico N and S fertilization and recovery of Brachiaria brizantha cv. Marandu pasture on sandy soil

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Patrícia Perondi Anchão Oliveira

2005-08-01

Full Text Available Com o objetivo de avaliar a resposta de pastagens degradadas de Brachiaria brizantha cv. Marandu ao uso de diferentes doses de fertilização com N e S, foi desenvolvido um experimento em campo durante dois anos, em área de cerrado em blocos ao acaso. Foram avaliados sete tratamentos, seis com diferentes combinações de doses de N e S e uma testemunha (pastagem degradada. As combinações foram: 70 kg ha-1 N sem enxofre, 140 kg ha-1 N sem enxofre, 210 kg ha-1 N sem enxofre, 70 kg ha-1 N e 77 kg ha-1 S, 140 kg ha-1 N e 153 kg ha-1 S, 210 kg ha-1 N e 230 kg ha-1 S. A reposta em produção de forragem ao uso de fertilização nitrogenada foi linear, com maior eficiência de uso do nitrogênio no segundo ano de manejo. A maior produção de forragem foi acompanhada por maior extração de N e queda nos teores de matéria orgânica no solo. A extração de enxofre foi menor que as doses de S empregadas. O critério da relação N:S na forragem na nutrição mineral da forrageira foi recomendado apenas na época das águas. Houve acúmulo de enxofre nas camadas subsuperficiais do solo.An experiment was carried out during two years on Cerrado soil with the objective of evaluating the response of degraded Brachiaria brizantha cv. Marandu pastures to different N and S fertilization doses. Seven treatments, six with different N and S combinations and a control (degraded pasture, were compared in a randomized complete blocks design. The combinations were: 70 kg ha-1 N without sulphur, 140 kg ha-1 N without sulphur, 210 kg ha-1 N without sulphur, 70 kg ha-1 N and 77 kg ha-1 S, 140 kg ha-1 N and 153 kg ha-1 S, 210 kg ha-1 N and 230 kg ha-1 S. Herbage yield response to nitrogen rates was linear, and the best efficiency of nitrogen use was obtained in the second year. The highest herbage yield was associated with higher extraction of N and smaller soil organic matter content. The sulfur extraction was lower than S doses. The N:S ratio as a criterion of the

Structural characteristics signal-grass under continuois stoking and nitrogen fertilization

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Rodrigo Vieira de Morais

2010-01-01

Full Text Available From February to November 2003, the mass and morphological composition of forage from Brachiaria decumbens cv. Basilisk pastures under four different doses of nitrogen (75, 150, 225 and 300 kg/ha/year were evaluated. The pastures were managed under continuous stocking with growing cattle. The data were grouped within three periods: February to April, May to August and September to November. Randomized block design with subdivided plots and two repetitions was used. The plots correspond to the nitrogen (N doses, while the subplots to the time of the evaluation. In the period from May to August, the forage mass in the B. decumbens pasture increased linearly related to the N dose. The percentage of green leaf blade (GLB was lower in the May/August period if compared to the other periods. The highest percentage values for green stem (GS ocorred February/April. The relation between LFV masses and CV were influenced by the period of evaluation, reaching higher values in September/November. When 75 kg ha-1 of N was applied, the senescent tissue (ST participation in the pasture did not vary throughout the months of the year. However, when whith doses of 150 kg ha-1 of N were applied, the percentage of ST was lower for February/April in comparison to the other periods. The percentages of GFB and GS increased linearly and positively as the N doses increased in the February/April. The structure of the B. decumbens pasture under continuous stocking is influenced interactively by the nitrogen doses and time of the year. Nitrogen fertilization improves the structure of the B. decumbens pasture under continuous stocking managed with the same mean height.

Consorciação de braquiárias com milho outonal em plantio direto sob pivô central Consortium of pasture with fall corn in no tillage under center pivot

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Carlos A. Chioderoli

2010-12-01

Full Text Available Em regiões de clima tropical, com altas taxas de decomposição do material orgânico, uma alternativa para suprir o aporte anual de palha exigido para proporcionar a sustentabilidade do sistema plantio direto é a consorciação de forrageiras com culturas produtoras de grãos. Com o objetivo de identificar, no sistema de integração agricultura-pecuária, a melhor modalidade de consorciação de três espécies de braquiária (Brachiaria brizantha B. decumbens, e B. ruzizienses com milho outonal (linha, entrelinha e entrelinha na época de adubação de cobertura do milho, foi conduzido o presente trabalho. Foi utilizado o delineamento em blocos ao acaso, no esquema fatorial (3x3, com quatro repetições. Foram avaliadas: massa seca de palha do milho, massa seca da palha de braquiária, massa seca total de palha, massa de 1.000 grãos e produtividade de grãos. Os resultados demonstraram que, quando o foco principal da consorciação de milho com braquiária for produtividade de grãos e o foco secundário for formação de palha, a utilização da Brachiaria ruzizienses semeada na época de adubação de cobertura do milho proporcionou maiores valores de produtividade de grãos. Todos os tratamentos produziram quantidade de palha suficiente para a manutenção da estabilidade do sistema de semeadura direta.In tropical regions with high rates of organic material decomposition, an alternative to supply the annual amount of straw required to provide the no tillage system sustainability is the use of intercrop of forage plants with grain crop. The present work was conducted with the objective of identify the best intercrop modality of three species of brachiaria (Brachiaria brizantha, B. decumbens and B. ruziziensis with fall maize (row, interrow, interrow at the moment of maize coverage fertilization in the pasture-agriculture integration system. It was used a randomized block design in a factorial scheme (3x3 with four repetitions evaluating

Viabilidade de sementes de papuã (Brachiaria plantaginea e a cobertura do solo com palha Alexandergrass (Brachiaria plantaginea seed viability and soil cover with straw

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Giovani Theisen

1999-09-01

Full Text Available O objetivo deste trabalho foi determinar o efeito de palha de aveia preta (Avena strigosa sobre o solo, na dormência e quiescência de sementes de papuã (Brachiaria plantaginea. Os tratamentos testados foram cobertura do solo (0; 2,6; 5,2; 7,8 e 10,5t/ha, o tempo de permanência das sementes submetidas à ação da cobertura do solo (40, 70, 100, 200 e 300 dias e o posicionamento das sementes (2 e 10cm. Elevados níveis de cobertura sobre o solo aumentaram o percentual de sementes de papuã viáveis. Sementes próximas da superfície do solo apresentaram menor dormência e quiescência do que aquelas posicionadas a 10cm de profundidade. A dormência e a quiescência das sementes de papuã se reduziram com o decorrer do tempo.The objective of this work was to determine the effect of black oat (Avena strigosa residues on the viability of alexandergrass (Brachiaria plantaginea seeds. The factors studied were the level of residues on the soil (0, 2.6, 5.2, 7.8 and 10.5t/ha, the time of permanence of seeds in soil submitted to action of residues (40, 70, 100, 200 and 300 days and the seed placement (2 and 10cm. High levels of crop residues on the soil surface increased the seed viability. Seeds placed at 2.0cm presented smaller dormancy and quiescence than those at 10cm depth. Seed dormancy and quiescence were reduced with time.

Fungos micorrízicos no crescimento e na extração de metais pesados pela braquiária em solo contaminado Mycorrhizal fungi influence on brachiariagrass growth and heavy metal extraction in a contaminated soil

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Silvana da Silva

2006-12-01

Full Text Available Avaliou-se, em casa de vegetação, a influência de 14 isolados de fungos micorrízicos arbusculares (FMA no crescimento e extração de Zn, Cd, Cu e Pb pela Brachiaria decumbens em solo contaminado. Foram utilizadas plantas com e sem FMA, em vasos com 0,92 kg de solo com (mg kg-1: Zn, 3.300; Cu, 60; Cd, 29; Pb, 73. Os isolados fúngicos tiveram efeitos diferenciados no crescimento e aumentaram a produção de matéria seca em 84%. Os teores de metais na planta foram elevados e apresentaram relação inversa com a produção de matéria seca. Verificou-se que os FMA não afetaram os teores de Pb, mas reduziram em 20, 28 e 63% os teores de Zn, Cd e Cu na parte aérea, respectivamente, e aumentaram os teores de Cu nas raízes em mais de 1.000%. Os FMA aumentaram a quantidade de metais extraídos do solo em 845, 142, 68 e 54% para Cu, Pb, Zn e Cd, respectivamente. Acaulospora spinosa, Acaulospora morrowiae-UFLA e Gigaspora gigantea aumentaram a extração simultânea dos quatro metais contaminantes. Os FMA, de acordo com a espécie, aumentam a capacidade da B. decumbens de extrair metais pesados do solo.The influence of 14 arbuscular mycorrhiza fungal isolates (AMF on brachiariagrass growth and extraction of Zn, Cd, Cu and Pb from a contaminated soil was evaluated in a greenhouse experiment. Mycorrhizal and nonmycorrhizal Brachiaria decumbens plants were grown in pots with 0.92 kg of soil containing (mg kg-1: Zn, 3,300; Cu, 60; Cd, 29; Pb, 73. The AMF increased dry matter yield in 84%. Plant heavy metal concentrations were high and were inversely related to dry matter yield. Isolates caused no effect on Pb, but reduced shoot Zn, Cd and Cu concentrations by 20, 28 and 63%, respectively. It was observed effect of mycorrhiza on Cu accumulation in roots (over 1,000%. Isolates enhanced the total amount of soil extracted metals by 845, 142, 68 and 54% for Cu, Pb, Zn and Cd, respectively. Only Acaulospora spinosa, Acaulospora morrowiae-UFLA and Gigaspora

Número e peso de perfilhos no pasto de capim-braquiária sob lotação contínua - doi: 10.4025/actascianimsci.v33i2.10438 Number and weight of tillers in signalgrass pasture under continuous stocking - doi: 10.4025/actascianimsci.v33i2.10438

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Virgilio Mesquita Gomes

2011-04-01

Full Text Available Objetivou-se estudar a relação entre o número e o peso de categorias de perfilhos em pasto de Brachiaria decumbens cv. Basilisk sob lotação contínua com bovinos. O pasto foi manejado com altura média de aproximadamente 25 cm. Foram avaliadas quatro alturas de plantas no mesmo pasto (10, 20, 30 e 40 cm, em delineamento de blocos ao acaso, com duas repetições. Os números de perfilhos vegetativos, vivos e totais reduziram linearmente com a altura da planta. O número de perfilho reprodutivo aumentou de forma linear com a altura da planta (de 8 para 84 perfilhos m-2 quando se comparam plantas de 10 a 40 cm. Os pesos dos perfilhos vegetativos e reprodutivos incrementaram linearmente com a altura da planta. O peso do perfilho vegetativo (0,316 g, em média foi menor do que o peso do perfilho reprodutivo (0,401 g, em média. A relação entre o número e o peso do perfilho vegetativo foi linear e negativa, enquanto que essa relação, para o perfilho reprodutivo, foi linear e positiva. Em locais com plantas altas há menor número de perfilhos vegetativos, bem como maior número de perfilhos reprodutivos e mortos. Nos locais mais altos do pasto de B. decumbens os perfilhos são mais pesados.The experiment was conducted to study the relationship between the number and weight of tiller categories in Brachiaria decumbens cv. Basilisk pasture managed under continuous stocking with cattle. The pasture was managed with an average height of about 25 cm. Plants of four different heights (10, 20, 30 and 40 cm were evaluated by means of the randomized block design with two replications. The number of vegetative tillers, both live and total, reduced linearly according to the plant height. The number of reproductive tillers increased linearly according to pasture plant height (from 8 to 84 tillers m-2 when comparing plants 10 to 40 cm high. Vegetative and reproductive tiller weight increased linearly according to pasture plant height. Vegetative tiller

Estrutura do capim-braquiária em relação à planta daninha - doi: 10.4025/actascianimsci.v33i3.10439 Structure of signalgrass in relation to weeds - doi: 10.4025/actascianimsci.v33i3.10439

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Guilherme Portes Silva

2011-06-01

Full Text Available O objetivo foi avaliar as características estruturais da Brachiaria decumbens cv. Basilisk em relação à planta daninha Solanum sisymbrifolium no pasto. Os tratamentos foram dois locais no mesmo pasto, quais sejam, próximo e distante da planta daninha. O delineamento foi em blocos ao acaso com três repetições. O pasto foi manejado sob lotação contínua, com bovinos e com altura média de aproximadamente 25 cm. Foram quantificadas as densidades populacionais das categorias de tamanho dos perfilhos, a altura, a interceptação de luz, as massas e as densidades volumétricas dos componentes morfológicos do pasto. No local distante da planta daninha houve maior ocorrência de perfilhos com tamanho inferior a 20 cm. Já no local próximo da planta daninha, predominaram perfilhos com tamanho superior a 40 cm. A presença da planta daninha ocasionou aumento na altura do pasto e incremento na interceptação de luz pelo dossel. As massas e as densidades volumétricas de lâmina foliar viva, colmo vivo e material morto foram inferiores no local próximo da planta daninha em relação ao local distante. A ocorrência da planta S. sisymbrifolium provoca variabilidade espacial da vegetação no pasto de B. decumbens manejado sob lotação contínua com bovinos.The objective of this study was to evaluate the structural characteristics of Brachiaria decumbens cv. Basilisk in relation to Solanum sisymbrifolium in pasture. The treatments were two sites in the same pasture, near and far from the weeds. A randomized block design with three replications was used. The pasture was managed under continuous stocking and grass height was kept at about 25cm. Densities were quantified for categories tiller size, height, light interception, masses and volumetric densities of morphological components of the pasture. In the site far from the weeds there is a higher occurrence of tillers with size smaller than 20 cm. In site near the weeds, tillers larger than 40

Número e peso de perfilhos no pasto de capim-braquiária sob lotação contínua = Number and weight of tillers in signalgrass pasture under continuous stocking

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Manoel Eduardo Rozalino Santos

2011-04-01

Full Text Available Objetivou-se estudar a relação entre o número e o peso de categorias de perfilhos em pasto de Brachiaria decumbens cv. Basilisk sob lotação contínua com bovinos. O pasto foi manejado com altura média de aproximadamente 25 cm. Foram avaliadas quatro alturas de plantas no mesmo pasto (10, 20, 30 e 40 cm, em delineamento de blocos ao acaso, com duas repetições. Os números de perfilhos vegetativos, vivos e totais reduziram linearmente com a altura da planta. O número de perfilho reprodutivo aumentou de forma linear com a altura da planta (de 8 para 84 perfilhos m-2 quando se comparam plantas de 10 a 40 cm. Os pesos dos perfilhos vegetativos e reprodutivos incrementaram linearmente com a altura da planta. O peso do perfilho vegetativo (0,316 g, em média foi menor do que o peso do perfilho reprodutivo (0,401 g, em média. A relação entre o número e o peso do perfilho vegetativo foi linear e negativa, enquanto que essa relação, para o perfilho reprodutivo, foi linear e positiva. Em locais com plantas altas há menor número de perfilhos vegetativos, bem como maior número de perfilhos reprodutivos e mortos. Nos locais mais altos do pasto de B. decumbens os perfilhos são mais pesados.The experiment was conducted to study the relationship between the number and weight of tiller categories in Brachiaria decumbens cv. Basilisk pasture managed under continuous stocking with cattle. The pasture was managed with an average height of about 25 cm. Plants offour different heights (10, 20, 30 and 40 cm were evaluated by means of the randomized block design with two replications. The number of vegetative tillers, both live and total, reduced linearly according to the plant height. The number of reproductive tillers increased linearly according to pasture plant height (from 8 to 84 tillers m-2 when comparing plants 10 to 40 cm high. Vegetative and reproductive tiller weight increased linearly according to pasture plant height. Vegetative tiller

Estrutura do capim-braquiária em relação à planta daninha = Structure of signalgrass in relation to weeds

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Manoel Eduardo Rozalino Santos

2011-07-01

Full Text Available O objetivo foi avaliar as características estruturais da Brachiaria decumbens cv. Basilisk em relação à planta daninha Solanum sisymbrifolium no pasto. Os tratamentos foram dois locais no mesmo pasto, quais sejam, próximo e distante da planta daninha. O delineamento foi em blocos ao acaso com três repetições. O pasto foi manejado sob lotação contínua, com bovinos e com altura média de aproximadamente 25 cm. Foram quantificadas as densidades populacionais das categorias de tamanho dos perfilhos, a altura, a interceptação de luz, as massas e as densidades volumétricas dos componentes morfológicos do pasto. No local distante da planta daninha houve maior ocorrência de perfilhos com tamanho inferior a 20 cm. Já no local próximo da planta daninha, predominaram perfilhos com tamanho superior a 40 cm. A presença da planta daninha ocasionou aumento na altura do pasto e incremento na interceptação de luz pelo dossel. As massas e as densidades volumétricas de lâmina foliar viva, colmo vivo e material morto foram inferiores no local próximo da planta daninha em relação ao local distante. A ocorrência da planta S. sisymbrifolium provoca variabilidade espacial da vegetação no pasto de B. decumbens manejado sob lotação contínua com bovinos.The objective of this study was to evaluate the structural characteristics of Brachiaria decumbens cv. Basilisk in relation toSolanum sisymbrifolium in pasture. The treatments were two sites in the same pasture, near and far from the weeds. A randomized block design with three replications was used. The pasture was managed under continuous stocking and grass height was kept at about 25cm.Densities were quantified for categories tiller size, height, light interception, masses and volumetric densities of morphological components of the pasture. In the site far from the weeds there is a higher occurrence of tillers with size smaller than 20 cm. In site near the weeds, tillers larger than 40 cm

Competição de plantas daninhas com a cultura do café em duas épocas de infestação Competition of weeds with coffee plants, in two times of infestation

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C.M.T. Fialho

2010-01-01

Full Text Available Objetivou-se com este trabalho avaliar a interferência de plantas daninhas instaladas aos 60 e aos 180 dias após o transplantio de plantas de café em vasos contendo 25 dm³ de substrato. O experimento foi instalado no delineamento em blocos casualizados, com quatro repetições, em esquema fatorial (2 x 4 x 2, com duas espécies de plantas daninhas (Brachiaria decumbens e Brachiaria plantaginea, cultivadas por 90 dias, em quatro densidades (zero, dois, quatro e seis plantas por vaso, juntamente com mudas de café de diferentes idades: 60 e 180 dias após transplantio. Na colheita do experimento foram avaliados o incremento na altura, na área foliar e no diâmetro do coleto do café, a matéria seca de plantas daninhas e do café e a densidade radicular do café. Estimaram-se, ainda, a razão de massa foliar, a razão de massa caulinar, a razão de massa radicular, a razão de área foliar e a razão sistema radicular/parte aérea das plantas de café. As plantas daninhas proporcionaram interferência negativa nas características avaliadas. Verificou-se menor incremento em altura, área foliar e matéria seca total das plantas de café com o aumento da densidade das plantas daninhas. O efeito da interferência das plantas daninhas foi maior quando a interferência se instalou aos 60 dias após o transplantio. Nesse caso, houve menor acúmulo das variáveis de crescimento, porém as duas gramíneas comportaram-se de forma similar, não diferindo para a maioria das variáveis. As plantas de café foram mais sensíveis à competição com B. plantaginea em relação a B. decumbens quando a competição se instalou aos 180 dias após o transplantio. O aumento da densidade de plantas daninhas promoveu maior alocação de fotoassimilados para a parte aérea em detrimento do sistema radicular do café.The aimed of this work was to evaluate the weed interference installed at 60 and 180 days after coffee seedlings transplanted in pots contend 25 dm

Controle de dez espécies daninhas em cana-de-açúcar com o herbicida mesotrione em mistura com ametryn e metribuzin Control of ten weed species in sugarcane using mesotrione mixed with ametryn and metribuzin

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F.T. Carvalho

2010-01-01

Full Text Available Existem muitas opções de herbicidas para aplicações em pré-emergência em cana-de-açúcar, mas o grande desafio atual para a cultura é o controle pós-emergente. O objetivo deste trabalho foi avaliar a eficácia do herbicida mesotrione em mistura com ametryn e metribuzin no controle em pós-emergência de 10 espécies daninhas semeadas em cana-de-açúcar, variedade RB 86-7515. As espécies daninhas selecionadas para o experimento foram: Brachiaria decumbens, Brachiaria plantaginea, Cenchrus echinatus, Digitaria horizontalis, Panicum maximum, Amaranthus deflexus, Bidens pilosa, Euphorbia heterophylla, Ipomoea nil e Sida glaziovii, semeadas nas entrelinhas após a emergência da cultura. Os herbicidas foram aplicados aos 45 dias após o plantio da cana-de-açúcar, com as plantas daninhas monocotiledôneas na fase de terceiro perfilho e as dicotiledôneas com três a quatro pares de folhas, e constaram dos seguintes tratamentos: mesotrione (120 g ha-1; ametryn (2.000 g ha-1; metribuzin (1.920 g ha-1; mesotrione + ametryn (120 g + 2.000 g ha-1; mesotrione + metribuzin (120 g + 1920 g ha-1 e testemunhas no mato e no limpo. Concluiu-se que os herbicidas isolados ou em mistura foram seletivos à cana-de-açúcar. Com relação à eficácia, observou-se que o herbicida mesotrione foi eficiente no controle de A. deflexus; ametryn, no controle de A. deflexus, B. pilosa e I. nil; metribuzin, no controle de A. deflexus, B. pilosa e S. glaziovii; mesotrione + ametryn, no controle de B. decumbens, B. plantaginea, D. horizontalis, P. maximum, A. deflexus, B. pilosa, I. nil e S. glaziovii; e mesotrione + metribuzin, no controle de B. plantaginea, D. horizontalis, P. maximum, A. deflexus, B. pilosa e S. glaziovii. Foi constatado elevado efeito sinergístico do mesotrione com os herbicidas testados, sendo o efeito mais pronunciado na mistura com o ametryn.There are many herbicide application options for sugarcane pre-emergence but, currently, post

Estabilidade de agregados de um latossolo vermelho degradado em recuperação com adubos verdes, calcário e gesso

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Carolina dos Santos Batista Bonini

2011-08-01

Full Text Available A utilização incorreta dos solos e as grandes construções no meio rural vêm causando alterações no ambiente edafoclimático, o que torna os solos menos produtivos, aumentando assim as áreas degradadas. Tendo em vista esse problema, o presente trabalho teve como objetivo avaliar a recuperação de um Latossolo Vermelho que se encontra há 17 anos com o uso de adubos verdes, calcário, gesso e braquiária. Foi utilizada a qualidade da estrutura como indicadora da recuperação do solo. O trabalho foi desenvolvido em delineamento experimental inteiramente casualizado, com nove tratamentos e quatro repetições. Os tratamentos foram: testemunha (solo mobilizado até 1999, sendo depois implantada Brachiaria decumbens; mucuna-preta (Stizolobium aterrimum Piper & Tracy até 1999, substituída por B. decumbens; guandu (Cajanus cajan (L. Millsp até 1994, substituído por feijão-de-porco (Canavalia ensiformis (L. e, a partir de 1999, por B. decumbens; calcário+mucuna-preta até 1999, substituído por B. decumbens; calcário+guandu até 1994, substituído por feijão-de-porco e, a partir de 1999, por B. decumbens; calcário+gesso+mucuna-preta até 1999, substituído por B. decumbens; calcário+gesso+guandu até 1994, substituído por feijão-de-porco e, partir de 1999, por B. decumbens; e duas testemunhas: solo exposto (sem técnica de recuperação e vegetação nativa de Cerrado. Foi avaliada a estabilidade de agregados em água e o conteúdo de matéria orgânica nas camadas de 0-10, 10-20 e 20-40 cm. O solo vem sendo recuperado, e a qualidade da estrutura, comparada à condição natural de Cerrado, na camada de 0-10 cm foi mais alterada positivamente; os tratamentos que receberam calcário e gesso foram os melhores, e o teor de matéria orgânica nessa camada foi superior ao das demais. Abaixo da camada superficial do solo, os tratamentos estão agindo de forma semelhante. O solo exposto, em todas as camadas, apresentou-se com má qualidade

The Wound Healing Effects of Herbal Cream Containing Oliveria Decumbens and Pelargonium Graveolens Essential Oils in Diabetic Foot Ulcer Model.

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Mahboubi, Mohaddese; Taghizadeh, Mohsen; Khamechian, Tahereh; Tamtaji, Omid Reza; Mokhtari, Rasoul; Talaei, Sayyed Alireza

2018-01-01

The number of diabetic patients in adult population is increasing. All this population are at risk of developing diabetic foot ulcers (DFUs) that are associated with unwanted ailments and high mortality. In spite of current therapies for DFUs, further therapies are needed to help the patients. The efficacy of herbal cream containing Pelargonium graveolens and Oliveria decombens essential oils was evaluated topically for treatment of DFUs in rat animal model in comparison with two other herbal formulas containing each essential oil alone, placebo (the basic formula without active ingredients) and normal saline as control groups. After anesthesia of diabetic rats (n=75) induced by streptozotocin (STZ), diabetic wounds were visible on the hind dorsal surface of the foot . The treatments were initiated on Day 1 and repeated 3 times a day for thirteen consecutive days. On day 1, 3, 5, 8 and 13, the wound sizes were determined and assessed histologically. Three herbal formulations reduced the size of wounds in rats with DFUs, while the cream containing combined herbals of O. decumbens and P. graveolens essential oils had the highest tissue repair in DFU rat models. Due to better wound healing effects of combined herbal cream containing O. decumbens and P. graveolens essential oils, it can be recommended in treatment of DFUs.

The Damage Capacity of Mahanarva spectabilis (Distant, 1909 (Hemiptera: Cercopidae Adults on Brachiaria ruziziensis Pasture

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Tiago Teixeira Resende

2013-01-01

Full Text Available The aim of this study was to determine the damage caused by adult Mahanarva spectabilis (Distant, 1909 (Hemiptera: Cercopidae on Brachiaria ruziziensis (Germain & Evard under field conditions. A total of 0, 4, 8, 12, or 16 M. spectabilis adults per plot were maintained for 6 days. Thereafter, the insects were removed from the plant, and the following parameters were evaluated: chlorophyll content, damage score, dry as well as fresh weights, percentage of shoots’ dry matter, and the forage’s ability to regrow. The chlorophyll content was significantly reduced; the damage score and percentage of dry matter in plants increased depending on the increased insect infestation density after 6 days of exposure. In contrast, no change was observed on the B. ruziziensis fresh and dry weights as well as the regrowth capacity depending on the M. spectabilis infestation densities. Attacks by 8 adult M. spectabilis per clump of B. ruziziensis with an average of 80 tillers for 6 days were sufficient to reduce the chlorophyll content and the functional plant loss index. This density can be a reference for spittlebug integrated management in Brachiaria.

DIAGNOSIS OF ENVIRONMENTAL DEGRADED PASTURES IN AREAS OF MUNICIPAL GURUPI-TO

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Gilson Araújo de Freitas

2016-03-01

Full Text Available Environmental degradation in grassland areas is a major constraint for the performance of ranching, which dominates the extensive grazing system on pasture. Therefore, this study aimed to carry out environmental assessment of pasture degradation areas in the municipality of Gurupi-TO. An environmental diagnosis was conducted in four properties: farm “Morada do Boi III”, farm “Jatobá”, and farm “Nova Esperança”. The environmental degradation was evaluated according to the following methods: (a Interview structured in a questionnaire in order to survey: formation, degradation, rehabilitation and maintenance of pastures; (B Soil sample collecting, 0-20 cm; and (c Visual assessment of the environmental degradation level. With regard to the third method, five different parameters such as: Strength and Quality of pasture, Plant population, Weeds, Ground cover, and Erosion were utilized in this evaluation. According to this, individual keys were set up for each parameter, keys that range from 1 to four 4, in which 1 was 75%. It was observed that the four properties are in degradation, but each at a different level. It was found moderate to very strong degradation, as is the case of farm “Jatobá”. It was observed, in all properties, that the soil fertility in decline is related to pasture degradation. Thus, environmental recovery strategies in the four properties are required. Keywords: soil fertility; degradation of pastures; Brachiaria brizantha.

Influence of soil fertility on waterlogging tolerance of two Brachiaria grasses

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Juan de la Cruz Jiménez

2015-04-01

Full Text Available As a consequence of global warming, rainfall is expected to increase in several regions around the world. This, together with poor soil drainage, will result in waterlogged soil conditions. Brachiaria grasses are widely sown in the tropics and, these grasses confront seasonal waterlogged conditions. Several studies have indicated that an increase in nutrient availability could reduce the negative impact of waterlogging. Therefore, an outdoor study was conducted to evaluate the responses of two Brachiaria sp. grasses with contrasting tolerances to waterlogging, B. ruziziensis (sensitive and B. humidicola (tolerant, with two soil fertility levels. The genotypes were grown with two different soil fertilization levels (high and low and under well-drained or waterlogged soil conditions for 15 days. The biomass production, chlorophyll content, photosynthetic efficiency, and macro- (N, P, K, Ca, Mg and S and micronutrient (Fe, Mn, Cu, Zn and B contents in the shoot tissue were determined. Significant differences in the nutrient content of the genotypes and treatments were found. An increase of redoximorphic elements (Fe and Mn in the soil solution occurred with the waterlogging. The greater tolerance of B. humidicola to waterlogged conditions might be due to an efficient root system that is able to acquire nutrients (N, P, K and potentially exclude phytotoxic elements (Fe and Mn under waterlogged conditions. A high nutrient availability in the waterlogged soils did not result in an improved tolerance for B. ruziziensis. The greater growth impairment seen in the B. ruziziensis with high soil fertility and waterlogging (as opposed to low soil fertility and waterlogging was possibly due to an increased concentration of redoximorphic elements under these conditions.

Beef production in irrigated and fertilized pastures of Brachiaria hybrid cv. Mulato II at the Sinú valley

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Sony Reza

2015-01-01

Full Text Available The main objective of this study was to evaluate the production of meat during the dry period in Brachiaria hybrid cv. Mulato II pasture with three stocking rates, irrigated and spring fertilized. The research was conducted for 140 days at the Center for Research Turipaná of the Colombian Corporation of Agricultural Research (Corpoica, located at Cereté, Córdoba (Colombia. Were grazed 48 cattle, commercial zebu with average weight of 339 ± 29 kg in an area of 12 hectares. Three treatments (3, 4, 5 animals/ha were evaluated with two replications in a randomized block design. Production, chemical and botanical composition, in situ degradability of dry matter and the daily weight gain was determined. Economic feasibility was determined by the benefit/cost ratio. The dry matter production was 1.925.16, 1.111.18 and 884.92 kg ha-1 for treatments 3, 4, 5 animal/ha respectively, detected differences (p0.05. For daily gain analysis found differences (p<0.05, with gains of 1.07, 0.989 and 0.940 kg animal for treatments 3, 4, 5 animal/ha. The treatment 5 animal/ha provided the best indicators economical.

Brachiaria spp. poisoning in cattle in Mato Grosso do Sul, Brazil

OpenAIRE

Souza, Roosevelt I.C.; Riet-Correa, Franklin; Brum, Karine B.; Fernandes, Carlos Eurico; Barbosa-Ferreira, Marcos; Lemos, Ricardo A. Amaral de

2010-01-01

Mediante a revisão dos arquivos das fichas de necropsia do Laboratório de Patologia Animal, Universidade Federal do Mato Grosso do Sul, foram estudados a epidemiologia, o quadro clínico e a patologia de 29 surtos de intoxicação por Brachiaria spp., ocorridos em bovinos de corte, no Mato Grosso do Sul, de março de 1996 a novembro de 2009. Os surtos ocorreram em todas as épocas do ano, tanto na seca quanto na chuva. Em 24 dos 29 surtos o principal sinal clínico foi a fotossensibilização e em ci...

Germination of tropical forage seeds stored for six years in ambient and controlled temperature and humidity conditions in Thailand

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Michael D. Hare

2018-01-01

Full Text Available The germination performances of fresh seed lots were determined for 5 tropical forage species: Mulato II hybrid brachiaria [Urochloa ruziziensis (syn. Brachiaria ruziziensis x U. decumbens (syn. B. decumbens x U. brizantha (syn. B. brizantha], Mombasa guinea [Megathyrsus maximus (syn. Panicum maximum], Tanzania guinea [M. maximus (syn. P. maximum], Ubon paspalum (Paspalum atratum and Ubon stylo (Stylosanthes guianensis, stored under ambient conditions in Thailand (mean monthly temperatures 23‒34 ºC; mean monthly relative humidity 40‒92% or in a cool room (18‒20 ºC and 50% relative humidity for up to 6 years. The first paper of this study showed all seeds, except unscarified Ubon stylo seed, were dead after a single year of storage in ambient conditions. This second paper shows that cool-room storage extended seed viability, but performance varied considerably between species. Germination percentage under laboratory conditions declined to below 50%, after 3 years storage for Mombasa guinea seed and Tanzania guinea seed, 4 years for Ubon paspalum seed and 4‒5 years for Mulato II seed. Ubon stylo seed maintained high germination for 5 years, in both cool-room storage (96% and ambient-room storage (84%. Apparent embryo dormancy in acid-scarified Mulato II seed steadily increased with time in cool-storage and this seed had to be acid-scarified again each year at the time of germination testing to overcome dormancy. Physical dormancy of Mulato II seeds, imposed by the tightly bound lemma and palea in unscarified seed, was not overcome by length of time in cool-storage and these seeds had to be acid-scarified to induce germination. Hardseeded percentage in Ubon stylo seed remained high throughout the study and could be overcome only by acid-scarification. The difficulties of maintaining acceptable seed germination percentages when storing forage seeds in the humid tropics are discussed.

Chemical amendment and phytostabilization of an industrial residue contaminated with Zn and Cd Correção química e fitoestabilização de um resíduo industrial contaminado com Zn e Cd

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Fabiana Soares dos Santos

2007-10-01

Full Text Available Phytostabilisation of a contaminated soil with heavy metals is considered a very appropriate technology to reduce erosion and dispersion of contaminants. A greenhouse study was conducted to evaluate the effects of both chemical amendments (calcium silicate and brewery sludge, and phytoremediation using the grass Brachiaria decumbens, on an industrial residue contaminated with Zn and Cd (industrial residue. Industrial residue samples placed into 30 L containers were amended with 20% brewery sludge, calcium silicate (2%, 3%, and 20% of brewery sludge + calcium silicate (2.5%, 4%, and were compared to the control treatment (non-amended residue. After pH stabilization, B. decumbens plants were grown on all treatments in order to evaluate the ability of the species to tolerate high Zn and Cd concentrations from the residue. Samples were collected twice, at planting and harvesting, for pH determination and simple extractions with water, sodium nitrate, acetic acid and DTPA. Differences in Zn and Cd concentrations in extracts allowed to estimate the concentrations of these elements in the most likely chemical forms they are found in the residue. Alkaline and organic industrial amendments reduced Zn and Cd percentages, both in the soluble and exchangeable fractions, as well as caused the predominance of Zn and Cd in the most stable chemical fractions, such as complexed and precipitated compounds. B. decumbens was tolerant to Zn and Cd from the industrial residue after addition of the amendments.A fitoestabilização de solos contaminados com metais pesados é considerada uma boa alternativa para reduzir a erosão e dispersão de contaminantes no ambiente. Foi conduzido um experimento em casa-de-vegetação com o objetivo de avaliar a contenção química (silicato de cálcio e lodo do biodigestor de uma cervejaria e a fitorremediação pela Brachiaria decumbens, de um resíduo industrial contaminado com Zn e Cd, utilizando vasos de 30 L. Os tratamentos

Bioavailability of diuron, imazapic and isoxaflutole in soils of contrasting textures.

Science.gov (United States)

Inoue, Miriam H; Oliveira, Rubem S; Constantin, Jamil; Alonso, Diego G; Tormena, Cássio A

2009-11-01

This research was aimed at understanding the dynamics of the herbicides diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea], imazapic [2-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl)-5-methylnicotinic acid] and isoxaflutole [5-cyclopropyl-4-(2-methanesulfonyl-4-trifluoromethyl benzoyl)isoxazole] in two soils of different physico-chemical properties. To accomplish such intent, several greenhouse experiments were run. The bioavailability of diuron (0; 1.6 and 3.2 kg ha(-1)), imazapic (0; 98 and 122.5 g ha(-1)) and isoxaflutole (0; 35 and 70 g ha(-1)) was measured in samples from a sandy loam soil and a clay soil, by sowing a bioindicator (Brachiaria decumbens), at 0, 25, 50, 75 and 100 days after herbicides application (DAA). Diuron was very stable in clay soil, providing control equal to or higher than 92% of bioindicator, up to 100 DAA, as assumed by biomass accumulation. No differential effect was observed in sandy loam soil, even when 2x labeled rate were applied. Imazapic provided a short bioavailability in relation to B. decumbens, independent of rates applied. The persistence of isoxaflutole was longer in clay soil (28 to 30 days).

Abnormal spindle orientation during microsporogenesis in an interspecific Brachiaria (Gramineae hybrid

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Andréa Beatriz Mendes-Bonato

2006-01-01

Full Text Available This paper reports a case of abnormal spindle orientation during microsporogenesis in an interspecific hybrid of the tropical grass Brachiaria. In the affected plant, prophase I was normal. In metaphase I, bivalents were regularly co-oriented but distantly positioned and spread over the equatorial plate. In anaphase I, chromosomes failed to converge into focused poles due to parallel spindle fibers. As a consequence, in telophase I, an elongated nucleus or several micronuclei were observed in each pole. In the second division, the behavior was the same, leading to polyads with several micronuclei. A total of 40% of meiotic products were affected. The use of this hybrid in production systems needing good-quality seeds is discussed.

Efficiency of a reduced herbicide rate for Brachiaria brizantha control in sugarcane Eficiência de subdoses de herbicidas no controle de Brachiaria brizantha em cana-de-açúcar

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S.P. Tironi

2012-12-01

Full Text Available At different growth stages, weeds present different sensitivities to herbicides. Thus, the registered herbicide rate may be reduced under specific conditions, while maintaining satisfactory weed control. This study evaluated the efficiency of reduced rates of the formulated herbicide mixture Velpar K WG® (hexazinone + diuron + Volcane® (MSMA for Brachiaria brizantha control at different growth stages. Optimum weed control efficiency was obtained when applying 50% of the recommended rate in younger plants (plants with one to four leaves. In late applications, it is necessary to increase the herbicide rates and, under these conditions, 90% of the recommended rate for (diuron + hexazinone + MSMA was estimated to be the most economical one.Em estádios diferentes de crescimento, as plantas daninhas apresentam sensibilidade diferenciada aos herbicidas. Desse modo, as doses registradas dos herbicidas podem ser reduzidas em condições específicas, mantendo-se o controle satisfatório das plantas daninhas. Neste trabalho, avaliou-se a eficiência de subdoses da mistura dos herbicidas formulados Velpar K WG® (hexazinone + diuron + Volcane® (MSMA no controle de Brachiaria brizantha em diferentes estádios de crescimento. Ótima eficiência de controle da espécie daninha foi obtida com aplicação de 50% da dose recomendada, quando os herbicidas foram aplicados em plantas mais jovens (plantas com uma a quatro folhas. Em aplicações tardias, comprovou-se a necessidade de aumentar a dose para obter controle eficiente; nessas condições, a dose econômica ótima estimada foi de 90% da dose recomendada da mistura dos herbicidas (diuron + hexazinone + MSMA.

POLPA ÚMIDA DE TOMATE: EFEITOS SOBRE O DESEMPENHO DE BOVINOS CONFINADOS WET TOMATO POMACE: EFFECTS ON PERFORMANCE OF FEEDLOT CALVES

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Hélio Louredo da Silva

2007-09-01

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Este trabalho foi conduzido para avaliar os efeitos da inclusão de níveis crescentes de polpa úmida de tomate (PUT, em substituição ao feno de braquiaria decumbens (Brachiaria decumbens Staf, sobre o desempenho de bovinos confinados. Foram utilizados vinte bovinos mestiços E x Z com 12 meses de idade e peso inicial de 161 kg, alojados em grupos de cinco em baias de 60 m2. Os quatro tratamentos empregados foram: A Feno de braquiaria decumbens (FHRAQ 100% da matéria seca proveniente da forragem (MSF; B FBRAQ 73% + PUT 27% da MSF; C FBRAQ 46% + 54% PUT da MSF; D FBRAQ 19% + 81% PUT da MSF. Quatro concentrados compostos por farelo de soja, grão de milho triturado e minerais foram usados para manter as rações isocalóricas e isoprotéicas. O ganho de peso médio diário (GMD foi avaliado em intervalos de 28 dias. Não houve efeito dos tratamentos sobre o GMD (kg/dia: A 0,88; B 1,07; C 1,04 e D 1,21. Dessa forma, foi possível substituir até 80% da MS do FBRAQ com PUT sem efeitos negativos sobre o GMD.

PALAVRAS-CHAVE: Feno; subprodutos; ruminantes; nutrição.

The experiment was carried out to study the effect of increasing levels of tomato pomace (TP, substituting hay, on performance of feedlot calves. Twenty crossbred calves with 161 kg of initial body weight allocated in pens in groups of five were used. The four treatments empregated were: A Brachiaria decumbens hay (BRAD 100% of rougaghe dry matter (DM; B BRAD 73% + TP 27%; C BRAD 46% + TP 54% and D BRAD 19% + TP 81%. Four concentrates, composed

EFFECT OF LEGUME TREES ON SOIL MACROFAUNA OF A Brachiaria brizantha cv. MARANDU PASTURE EFEITO DE LEGUMINOSAS ARBÓREAS SOBRE A MACROFAUNA DO SOLO EM PASTAGEM DE Brachiaria brizantha cv. MARANDU

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Avílio Antonio Franco

2007-09-01

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The objective of this research was to evaluate the effect of four legume tree species in a Brachiaria brizantha cv. Marandu pasture on soil macrofauna density and diversity, in a low natural fertility soil. The tree leguminous species introduced in the pasture were Pseudosamanea guachapele, Mimosa artemisiana, Mimosa tenuiflora, and Enterolobium contortisiliquum. The macrofauna sampling consisted in collecting six soil monoliths with 25 cm x 25 cm x 30 cm under tree canopies or in a transect in the single Brachiaria pasture. The densities varied from 602 individuals.m-2 under the canopy of E. contortisiliquum to two individuals.m-2 in the single pasture. The largest group richness was found under M. tenuiflora canopy (ten groups, followed by P. guachapele (nine groups, E. contortisiliquum (seven groups and M. artemisiana (six groups. The leguminous species influence was related to N content and to C:N ratio of leaf material. M. artemisiana and M. tenuiflora favored the occurrence of Oligochaeta and Coleoptera larvae, while under the P. guachapele and E. contortisiliquum canopies Formicidae activity was more intense.

KEY-WORDS: Soil macrofauna; sivipastoral systems; soil quality.

O objetivou deste trabalho foi avaliar o efeito de quatro espécies leguminosas arbóreas, em uma pastagem de Brachiaria brizantha cv. Marandu, com dois anos de estabelecimento, sobre a densidade e diversidade da macrofauna de um planossolo de baixa fertilidade natural. As espécies arbóreas introduzidas na pastagem foram: Pseudosamanea guachapele, Mimosa artemisiana, Mimosa tenuiflora e Enterolobium contortisiliquum. A amostragem da macrofauna consistiu na retirada de seis monolitos de solo com 25 cm x 25 cm x 30 cm sob a copa das árvores ou em um transecto na pastagem solteira. As densidades variaram de 602

Eficácia de glyphosate em plantas de cobertura Efficacy of glyphosate in cover crops

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P.C. Timossi

2006-09-01

Full Text Available Objetivou-se comparar a eficácia de três dosagens do herbicida glyphosate para a dessecação de Brachiaria decumbens, B. brizantha cv. Marandu e vegetação espontânea, visando a adoção do sistema plantio direto. Utilizou-se delineamento experimental de blocos ao acaso, num esquema fatorial 3 x 3, com quatro repetições. Testaram-se três tipos de cobertura vegetal e três dosagens de glyphosate (1,44, 2,16 e 2,88 kg ha-1. Aos 7, 14, 21 e 28 dias após a aplicação (DAA, foram feitas avaliações visuais da porcentagem de controle das coberturas vegetais e, aos 45 DAA, avaliações visuais da porcentagem de reinfestação da área. Conclui-se que, para as espécies que compunham a vegetação espontânea, o uso de 1,44 kg ha-1 proporcionou bom controle, sem no entanto evitar rebrotes de Digitaria insularis. Para as braquiárias, a mesma taxa de controle foi observada a partir de 2,16 kg ha-1. A camada de palha das braquiárias sobre o solo não foi capaz de suprimir a emergência de Cyperus rotundus, Alternanthera tenella, Raphanus raphanistrum, Bidens pilosa e Euphorbia heterophylla.This work aimed to compare rates of glyphosate to desiccate Brachiaria decumbens, B. brizantha cv. Marandu and spontaneous plants (weeds, aiming to adopt the no-tillage system. A randomized block experimental design in a factorial scheme was used (3x3, with four replications. The factors consisted of three species of cover crops and three rates of glyphosate (1.44, 2.16 and 2.88 kg ha-1. At 7, 14, 21 and 28 days after application of the herbicide, visual evaluations of the percentage of cover crop control were carried out and at 45 days of the reinfestation percentage of the area. It was concluded that the spontaneous plants presented a good control at 1.44 kg ha-1, without, however, preventing Digitaria insularis sprouts. The same control rate starting at 2.16 kg ha-1 was observed for the Brachiaria species. The straw layer of these cover crops on the soil

Nutrient Availability and Changes on Chemical Attributes of a Paleudult Soil Amended with Liquid Sewage Sludge and Cropped with Surinam Grass

International Nuclear Information System (INIS)

Ceolato, L.C.; Berton, R.S.; Coscione, A.R.

2011-01-01

The liquid sewage sludge (LSS) was applied on a field experiment during four years at successive applications to evaluate the changes in soil attributes and on Surinam grass (Brachiaria decumbens) uptake of nutrients. A randomized blocks experimental design, with two treatments (with and without LSS) and three repetitions, was used. Land application of LSS did not alter soil organic matter and exchangeable K until 40 cm depth. However, it increased soil ph, base saturation, labile P, and available Zn and did not change the concentrations of available B (hot water) and Cu, Fe, and Mn (DTPA) at 0-20 cm and 20-40 cm depths and LSS was a source of N, K, P, Ca, Mg, and Zn for the grass, but decreased leaf Mn concentration.

Effects of light intensity on growth, anatomy and forage quality of two tropical grasses (Brachiaria brizantha and Panicum maximum var. trichoglume).

NARCIS (Netherlands)

Deinum, B.; Sulastri, R.D.; Zeinab, M.H.J.; Maassen, A.

1996-01-01

Effects of light intensity on growth, histology and anatomy, and nutritive value were studied in seedlings of two shade tolerant species: Brachiaria brizantha and Panicum maximum var. trichoglume. They were studied under greenhouse conditions in pots with sandy soil and sufficient N and cut after a

Evaluación de la composición bromatológica de 24 accesiones de Brachiaria spp. Evaluation of the bromatological composition of 24 Brachiaria spp. accessions

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E.R Canchila

2009-12-01

Full Text Available Con el objetivo de caracterizar la composición bromatológica de diferentes accesiones e híbridos apomícticos de Brachiaria spp., en condiciones agroecológicas de Barrancabermeja, Santander, Colombia, se evaluaron 24 accesiones de este género. Se utilizó un diseño experimental completamente aleatorizado, en 72 parcelas de 21 m2 cada una y tres réplicas (parcelas para cada tratamiento. Se determinó la MS, la PB, los contenidos de grasa, cenizas y de fibra ácido detergente (FAD. Los contenidos de materia seca oscilaron en un rango de 23,4 a 25,7%; mientras que los de proteína estuvieron entre 5,8 y 7,5%, con los valores más bajos para B. humidicola CIAT-26159 y los más elevados en B. brizantha CIAT-6387y CIAT-26124. A pesar de que no se hallaron variaciones importantes en la composición bromatológica de las accesiones, las especies más promisorias en las condiciones agroecológicas evaluadas fueron: B. híbrido 1873, B. brizantha 16315 y B. brizantha 16488With the objective of characterizing the bromatological composition of different accessions and apomictic hybrids of Brachiaria spp., under the agroecological conditions of Barrancabermeja, Santander, Colombia, 24 accessions of this genus were evaluated. A completely randomized experimental design was used, with 72 plots of 21 m2 each and three replications (plots per treatment. The DM, CP, contents of fat, ash and acid detergent fiber (ADF were determined. The dry matter contents oscillated from 23,4 to 25,7%, while those of crude protein were between 5,8 and 7,5%; with the lowest values for B. humidicola CIAT-26159 and the highest in B. brizantha CIAT-6387 and CIAT-26124. Although no important variations were found in the bromatological composition of the accessions, the most promising species under the evaluated agroecological conditions were: B. híbrido 1873, B. brizantha 16315 and B. brizantha 16488.

Pasture height at the beginning of deferment as a determinant of signal grass structure and potential selectivity by cattle - doi: 10.4025/actascianimsci.v35i4.20421

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Manoel Eduardo Rozalino Santos

2013-10-01

Full Text Available Current experiment identified the height of signal grass {Urochloa decumbens (Stapf R. D. Webster cv. Basilisk [syn. Brachiaria decumbens Stapf cv. Basilisk]} at the beginning of deferment that provided an appropriate pasture structure and potential selectivity by cattle on deferred pastures. Four pasture heights at the beginning of deferment (10, 20, 30 and 40 cm and two forage samples (available on pasture and simulated grazing were studied. The experimental design was set in completely randomized blocks, with two replications, in a split-plot arrangement. Higher percentage of live leaf blades and lower percentage of live stems and senescent forage were recorded in the forage sample from simulated grazing. The increase in pasture height increased the percentage of senescent forage and reduced the percentage of live leaf blades in forage samples. Pasture height at the beginning of deferment did not affect the potential selectivity index by cattle for the percentage of live leaf blade. The potential selectivity index varied quadratically for the percentage of live stems and increased linearly for the percentage of senescent forage with pasture height. A 10-to-20 cm reduction in pasture height at the beginning of deferment improved the structure of deferred signal grass and optimized selectivity by cattle.  

CORRELATION COEFFICIENTS BETWEEN THE NUMBERS OF CATEGORIES TILLERS ON SIGNALGRASS PASTURE

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Manoel Eduardo Rozalino Santos

2011-07-01

Full Text Available The understanding of relationship between the numbers of tillers categories allows the identification of compensatory mechanisms that ensure plants adaptation to grazing. Thus, this work was conducted to evaluate the associations between densities of various tillers categories in same Brachiaria decumbens pasture under continuous stocking with cattle. The tillers were measured with different growth sources, developmental stages, and defoliation and sizes levels in sites of same pasture with plants of 10, 20, 30 and 40 cm. Pearson linear correlation between the different tillers categories were estimated. The vegetative tillers number (VTN correlated positively with percentage of tillers with up to 20 cm. The response pattern opposite occurred with reproductive (RTN and dead (DTN tillers numbers. The correlations of number of leafless tillers were positive with the percentage of tillers with less than 20 cm and negative with the percentage of tillers with more than 20 cm. The VTN correlated positively with numbers of tillers with and without defoliation, and negatively with the RNT and DNT. The number of aerial tiller was positively correlated with the number of tillers without apical meristem. In B. decumbens pasture there are tradeoffs between percentage of longer tillers and VNT, between numbers of vegetative and leafless tillers, and between VNT and RNT.

ORGANIC FERTILIZER AS PHOSPHORUS SUPPLIER FOR Brachiaria brizantha CV. MARANDÚ FERTILIZANTE ORGÂNICO COMO FONTE DE FÓSFORO NO CULTIVO INICIAL DE Brachiaria brizantha CV. MARANDÚ

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Diego Henriques Santos

2010-05-01

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Phosphorus is considered an essential element for plants, but it is found in low amounts in Brazilian soils, mainly in areas destined to pastures, and the application of organic matter contributes to the improvement of physical, chemical and biological soil attributes. The research had the objective of evaluating the application effects of the Bokashi organic compound on soil macro and micronutrients contents and leaves, as well as on Brachiaria brizantha cv. Marandú dry mass yield, evaluating the potential of the organic fertilizer as phosphorus source, in comparison with conventional chemical fertilizers. Different organic compound doses supplied the soil with 17 kg P₂O₅ ha^-1, 34 kg P₂O₅ ha^-1, 68 kg P₂O₅ ha^-1, 136 kg P₂O₅ ha^-1, and 204 kg P₂O₅ ha^-1, comparing it with the conventional chemical fertilizer and the control. The results revealed that the organic fertilizer Bokashi can adequately replace the conventional chemical fertilizer of Brachiaria brizantha cv. Marandú, supplying the soil and plant with appropriate nutrients levels and maintaining the dry mass yield.

KEY-WORDS: Organic matter; organic fertilizers; plants mineral nutrition; Bokashi

Tolerância do Tifton 85 (Cynodon spp. e da Brachiaria brizantha ao glyphosate Tifton 85 (Cynodon spp. and Brachiaria brizantha tolerance to glyphosate

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M.V. Santos

2008-06-01

Full Text Available Objetivou-se avaliar a tolerância de Tifton 85 e Brachiaria brizantha ao glyphosate e verificar o controle de B. brizantha em área de pastagem de Tifton 85 já estabelecida. O delineamento experimental foi em blocos casualizados, com quatro repetições, em que se testaram as doses: 0, 720, 1.440, 2.160 e 2.880 g ha-1 de glyphosate. Cada parcela possuía dimensões de 3,5 m de comprimento por 3,0 m de largura, totalizando 10,5 m², com área útil de 7,5 m ². A eficiência do herbicida no controle de B. brizantha e o nível de intoxicação nas plantas de Tifton 85 foram avaliados 15, 30 e 60 dias após aplicação (DAA, mediante escala de 0 a 100, em que 0 é ausência de controle e/ou intoxicação e 100, controle total ou morte das plantas. Para avaliação da produção e do potencial de rebrota das forrageiras, as plantas de ambas as espécies foram colhidas aos 300 DAA e secas em estufa. Observou-se controle acima de 90% das plantas de B. brizantha a partir das doses de 1.473,75 e 1.721,25 g ha-1 de glyphosate, aos 30 e 60 DAA, respectivamente. As porcentagens de intoxicação das plantas de Tifton 85, referente a estas doses de controle de B. brizantha, foram, respectivamente, de 24,90 e 4,13% aos 30 e 60 DAA. Além disso, aos 60 DAA, para a maior dose avaliada (2.880 g ha-1 de glyphosate foi observada intoxicação das plantas de Tifton 85 de apenas 18,22%. Aos 300 DAA, observou-se ausência de produção de massa seca de B. brizantha a partir da dose de 2.160 g ha-1 do herbicida, devido ao eficiente controle. Os resultados evidenciam maior tolerância das plantas de Tifton 85 ao glyphosate em relação às plantas de B. brizantha, possibilitando o controle desta espécie em pastagem estabelecida de Tifton 85, sem causar danos à forrageira cultivada.This study aimed to evaluate Tifton 85 and Brachiaria brizantha tolerance glyphosate and verity Brachiaria brizantha control in an established Tifton 85 pasture area. Rates of 0; 720; 1

Períodos de interferência das plantas daninhas na cultura do arroz de terras altas. II - cultivar Caiapó Interference periods of weeds in the upland rice - Caiapó variety

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Maria Rosangela Malheiros Silva

2009-01-01

Full Text Available Os experimentos foram desenvolvidos nos anos agrícolas 2003/2004 e 2004/2005, em área experimental da Universidade Estadual Paulista, Campus de Jaboticabal (SP, com o objetivo de se determinarem os períodos de interferência das plantas daninhas na cultura do arroz de terras altas, cultivar Caiapó. O delineamento experimental foi em blocos ao acaso com quatro repetições e 16 tratamentos. Os tratamentos foram constituídos por períodos crescentes de controle ou de convivência das plantas daninhas após a emergência da cultura: 0-10, 0-20, 0-30, 0-40, 0-50, 0-60, 0-70 dias e 0-colheita. Nos dois anos, as famílias predominantes eram Poaceae, Asteraceae, Amaranthaceae e Malvaceae e as principais plantas daninhas presentes foram: Cyperus rotundus L., Cenchrus echinatus L., Digitaria spp Heist., Echinochloa crus-galli (L. P. Beauv., Brachiaria decumbens Stapf., Eleusine indica Gaertn e Alternanthera tenella Colla. A cultivar de arroz de terras altas Caiapó deve ser mantida sem plantas daninhas nos 30 dias após a emergência.The experiments were carried out in two growing seasons (2003/04 and 2004/05 in an experimental area at São Paulo State University - UNESP, Jaboticabal Campus, to evaluate the weed interference periods on the upland Caiapó rice variety. The experimental design was randomized blocks with 4 replicates and 16 treatments. The treatments consisted of increasing periods of control or coexistence after emergence of the culture: 0-10; 0-20; 0-30; 0-40; 0-50; 0-60; 0-70 days; 0-harvest. The predominant families were Poaceae, Asteraceae, Amaranthaceae and Malvaceae, and the main weeds present were Cyperus rotundus L., Cenchrus echinatus L., Digitaria spp Heist., Echinochloa crus-galli (L. P. Beauv., Brachiaria decumbens Stapf., Eleusine indica Gaertn e Alternanthera tenella Colla for both years. The upland rice cultivar Caiapó is to be kept free of weeds for 30 days after emergence.

Azafenidin: novo herbicida para o controle de plantas daninhas em Eucalyptus camaldulensis Azafenidin: a new herbicide for weed control in Eucalyptus camaldulensis

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J. Constantin

2000-01-01

Full Text Available Um experimento de campo foi conduzido em Presidente Castelo Branco-PR, com o objetivo de avaliar a seletividade do herbicida azafenidin para a cultura de Eucalyptus camaldulensis, assim como sua eficácia no controle de algumas plantas daninhas infestantes nessa cultura. Azafenidin foi aplicado nas doses de 300, 400, 500 600 e 800 g i.a. ha-1, em pré-emergencia das plantas daninhas. Tratamentos adicionais, incluindo oxyfluorfen (720 g i.a. ha-1, uma testemunha capinada e outra testemunha sem capina, foram também incluídos. Tanto azafenidin quanto oxyfluorfen provocaram sintomas de toxicidade na cultura; no primeiro, as injúrias foram mais intensas em doses ³ 600 g i.a. ha-1. Em relação ao controle de plantas daninhas, doses de azafenidin a partir de 500 g i.a. ha-1 foram efetivas no controle de Brachiaria decumbens, Commelina benghalensis, Richardia brasiliensis e Sida santaremnensis, mesmo 180 dias após a aplicação. Doses menores de azafenidin resultaram em controle suficiente da maioria das plantas daninhas, mas com menor efeito residual.A field experiment was conducted at Presidente Castelo Branco, PR, Brazil, to evaluate the selectivity of the herbicide azafenidin to the crop Eucalyptus camaldulensis, as well as its efficacy to control some infesting weeds in this crop. Azafenidin was applied under pre-emergence conditions, at rates of 300, 400, 500, 600 and 800 g a.i. ha-1. Additional treatments, including oxyfluorfen (720 g a.i. ha-1, a weed free and a weeded check plots were also included. Both azafenidin and oxyflluorfen caused crop symptoms of phytotoxicity, with injuries being more intense for azafenidin at rates ³ 600 g a.i. ha-1. For weed control, rates of azafenidin at 500 g a.i. ha-1 or higher were effective in controlling Brachiaria decumbens, Commelina benghalensis, Richardia brasiliensis and Sida santaremnensis, even at 180 days after application. Lower rates of azafenidin provided enough control of most weeds, but

Eficácia do herbicida oxyfluorfen com a cobertura de palha no controle de plantas daninhas Efficacy of oxyfluorfen with straw cover in controlling weeds

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E. Negrisoli

2009-03-01

Full Text Available A palha pode alterar a dinâmica do herbicida oxyfluorfen no sistema de cana-crua; assim, este trabalho teve por objetivo avaliar a eficácia do oxyfluorfen em condições de casa de vegetação, com a cobertura de palha, no controle das plantas daninhas que ocorrem em cana-crua. Foram avaliadas as espécies de Brachiaria decumbens, Ipomoea grandifolia, Ipomoea quamoclit e Merremia cissoides. A dose utilizada do oxyfluorfen foi de 3 L ha-1 (720 g i.a. ha-1. Os tratamentos constaram de diferentes posicionamentos do herbicida e condições antes e após a aplicação. A porcentagem de controle das plantas daninhas foi avaliada aos 12, 20, 26, 33 e 38 DAA. Os maiores índices de controle aos 38 DAA, independentemente da planta daninha estudada, foram alcançados quando se aplicou oxyfluorfen em tratamentos com a presença de palha em cobertura, com ou sem umidade. No entanto, os resultados obtidos nos demais tratamentos mostraram-se eficientes no controle das diferentes espécies de plantas daninhas estudadas.Straw can change the dynamics of the herbicide oxyfluorfen in the raw sugarcane system. Thus, this study aimed to assess the effectiveness of oxyfluorfen with straw cover in controlling weeds in raw sugarcane under greenhouse conditions. The species Brachiaria decumbens, Ipomoea grandifolia, Ipomoea quamoclit and Merremia cissoids were evaluated and the dose used was oxyfluorfen 3 L ha-1 (720 g .i.a. ha-1. Treatments consisted of different herbicide positions and conditions before and after application. Weed control percentage was evaluated at 12, 20, 26, 33 and 38 DAA. The highest control rates at 38 DAA, regardless of the weed studied, were reached when oxyfluorfen was applied in treatments with the cover straw, with or without humidity. However, the results obtained in the other treatments were effective in controlling the different weed species studied.

Avaliação de fontes de amônia para o tratamento de fenos de gramíneas tropicais. 2. Compostos nitrogenados Evaluation of ammonia sources to tropical grasses hays treatment. 2. Nitrogen compounds

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Ricardo Andrade Reis

2001-06-01

Full Text Available Este estudo foi desenvolvido para se avaliarem as alterações nos conteúdos de compostos nitrogenados dos fenos de braquiária decumbens (Brachiaria decumbnes Stapf e jaraguá (Hyparrhenia rufa Ness Stapf não-tratados, tratados com uréia (U - 5,4% da MS, uréia (UL - 5,4% da MS mais labe-labe (Lablab purpureus L. Sweet, cv. Highworth-3,0% da MS ou amônia anidra (NH3 -3,0% da MS. A aplicação de amônia anidra ou de uréia aumentou os teores de N total, N insolúvel em detergente neutro, N insolúvel em detergente ácido, N não-protéico e N amoniacal. A amonização diminuiu as relações N insolúvel em detergente neutro/N total e N insolúvel em detergente ácido/N total e aumentou as relações N não-protéico/N total, N amoniacal/N total e os teores de PB. O N aplicado foi retido, principalmente, nas formas de NNP e N amoniacal.The experiment was conducted to evaluate the changes on the nitrogen compounds of the Brachiaria decumbens Stapf, jaraguá (Hyparrhenia rufa Ness Stapf grasses hay, untreated, treated with urea (5.4% DM, urea plus lab-lab (UL-5.4% DM plus Lablab purpureus L. Sweet, cv. Highworth-3.0% DM and anhydrous ammonia (NH3 - 3.0% DM. The chemical treatment with urea or NH3 increased the total N, neutral detergent insoluble N 9NDIN, acid detergent insoluble N (ADIN, non nitrogen protein (NNP, and the ammonical nitrogen (AN contents. Ammoniation decreased the NDIN/TN and ADIN/TN ratios. The chemical treatment increased the NNP/TN and NA/TN ratios, and the crude protein contents. The N applied as urea or NH3 was retained as NNP and in the ammoniacal form.

Seguimiento a patógenos presentes en biosólido empleado como enmienda para revegetalizar un talud Follow-up to pathogens present in biosolids used as emendation to reforest a slope

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Idalia Jacqueline López Sánchez

2010-07-01

Full Text Available Con el fin de evaluar la factibilidad del uso del biosólido como enmienda orgánica para el establecimiento de vegetación y el control de procesos erosivos superficiales activos, se seleccionó un corte de carretera ubicado sobrela Variante a Caldas (Antioquia. Para darle amarre y cobertura al suelo, se sembraron dos especies vegetales tipo pasto Brachiaria Decumbens y Kikuyo (Pennisetum clandestinum, utilizando biosólido proveniente de la PTAR San Fernando, mezclado con suelo de la zona. Se evaluó el comportamiento de bioindicadores de riesgo ambiental: coliformes totales, coliformes fecales, Salmonella-Shiguella, en las aguas de escorrentía y en el suelo del talud en el tiempo. Ambas especies se adaptaron bien amarrando el suelo; la cobertura fue total y permanente. Los resultados muestran la factibilidad del uso del biosólido como enmienda. Sin embargo, la permanencia de los parámetros microbiológicos medidos durante el tiempo de evaluación evidencia la necesidad de sanitizar el biosólido antes de usarlo, ya que estos patógenos constituyen un riesgo ambiental.In order to evaluate the feasibility of biosolids use as an organic emendation for reforestation and controlling active superficial erosive processes, a part of the highway -located near to the alternative route to Caldas (Antioquia. With the purpose of preventing erosion, two types of plants Brachiaria Decumbens and kikuyu grass (Pennisetum clandestinum were planted, using biosolids from San Fernando Water Treatment Plant, mixed with soil from the site. The behavior of some environmental risk bioindicators: total coliforms, fecal coliforms, Salmonella-Shiguella, were evaluated, in runoff waters and in the slope soil across the time. Both plant species adapted well to soil; the coverage was complete and permanent. Results show the feasibility of bio-solid as emendation. However, microbiological specifications measured during the evaluation time, showed the need for sanitizing

Effect of Soil Use and Coverage on the Spectral Response of an Oxisol in the VIS-NIR-MIR Region

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Javier M. Martín-López

2017-02-01

Full Text Available In this study, the spectral responses obtained from a Typic Red Hapludox (oxisol were analyzed under different uses and occupations: Ficus elastica cultivation, Citrus + Arachis association cultivation, transitional crops, forest, Mangifera indica, Anacardium occidentale, Elaeis guineensis (18 years, Brachiaria decumbens, Brachiaria brizantha, and Musa × paradisiaca + Zea mays at the La Libertad Research Center in the department of Meta in Colombia (4°04′ North latitude, 73°30′ West longitude, 330 MAMSL. Sampling was performed with four random replicates of the horizon A and B to determine the contents of organic carbon (CO, pH, exchangeable acidity (Ac. I, cation exchange capacity (Cc, P, Ca, Mg, K, Na, sand, lime, and clay and spectral responses were obtained in the visible band (VIS, near infrared (NIR, and infrared (MIR for each sample under laboratory conditions. A comparison was made between the obtained spectra, determining the main changes in soil properties due to their use and coverage. Variation of soil characteristics such as color, organic carbon content, presence of ferrous compounds, sand, silt, and clay content and mineralogy allow the identification of the main spectral changes of soils, demonstrating the importance of the use of reflectance spectroscopy as a tool of comparison and estimation between physical-chemical properties of the soils.

ATRIBUTOS FÍSICOS DO SOLO EM DIFERENTES COBERTURAS VEGETAIS NA REGIÃO SUL DO PIAUÍ

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ROBERTO LUSTOSA SILVA

2014-01-01

Full Text Available The management when done so improperly can cause changes in the physical, chemical and biological soil properties. The aim of this study was to evaluate the behavior of physical attributes in a dystrophic Oxisol under different vegetation covers and managements in the city of Chain southern state of Piauí. The experimental design was randomized using a split-plot with four types of cropping systems and four sampling depths, with three replications. Cropping systems were studied: Nim (Azadirachta indica, elephant grass (Pennisetum purpureum, Brachiaria decumbens and Native Forest sampling depths 0-0.10, 0.10-0.20, 0.20-0, 30 and 0.30-0.40 m. The effects of hedges and management on soil physical properties in different soil depths were recorded from the analysis of variance and treatment means compared by Tukey p <0.05. Determinations were carried out density, macroporosity, microporosity, total porosity, and resistance to penetration in all cropping systems. The elephant grass and native forest had the lowest values of penetration resistance and bulk density, higher values of total porosity and macroporosity, reflecting better physical condition of the soil. The area with Nim and Brachiaria was influenced by animal trampling, thus causing increase of soil density and hence the resistance to penetration.

Characterization and Potential Use of Biochar for the Remediation of Coal Mine Waste Containing Efflorescent Salts

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Luis Carlos Díaz Muegue

2017-11-01

Full Text Available In open pit coal mining, soil and vegetation are removed prior to the start of mining activities, causing physical, chemical, and microbiological changes to the soil and landscape. The present work shows the results of an integrated study of the remediation of mine waste with a high level of salt contamination in areas of the Cesar Department (Colombia, employing biochar as an amendment. Physical-chemical properties including Munsell color, texture, pH, electrical conductivity, water-holding capacity, cation exchange capacity, metal content, organic carbon, sulfates, extractable P, and total nitrogen were characterized both in the soils contaminated with mine residues and the biochar sample. A high concentration of sulfates, calcium, iron, and aluminum and a significant presence of Na, followed by minor amounts of Mg, K, Cu, and Mn, were observed in efflorescent salts. X-ray diffraction indicated a high presence of quartz and gypsum and the absence of pyrite and Schwertmannite in the efflorescent salt, while showing broad peaks belonging to graphene sheets in the biochar sample. Soil remediation was evaluated in Petri dish seed germination bioassays using Brachiaria decumbens. Biochar was shown to be effective in the improvement of pH, and positively influenced the germination percentage and root length of Brachiaria grass seeds.

Número de perfilhos do capim-braquiária em regime de lotação contínua - doi: 10.4025/actascianimsci.v33i1.10440 Tiller number in signalgrass under continuous stocking systems - doi: 10.4025/actascianimsci.v33i1.10440

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Simone Pedro da Silva

2011-02-01

Full Text Available Objetivou-se identificar, pela avaliação do perfilhamento, as estratégias adequadas de manejo da Brachiaria decumbens cv. Basilisk em lotação contínua com bovinos. Foram estudadas duas estratégias de manejo: pasto com 25 cm de altura durante todo período experimental, e pasto com 15 cm no inverno e 25 cm na primavera e verão. Foram adotados o esquema de parcelas subdivididas e o delineamento em blocos casualizados com quatro repetições. As estratégias de manejo foram o fator primário e as estações (inverno, primavera e verão, o fator secundário. O menor balanço entre taxas de aparecimento (TApP e de mortalidade de perfilhos (TMoP e o menor número de perfilho vegetativo ocorreram no inverno. Na primavera e verão, o balanço e o número de perfilhos vegetativos foram altos e similares. O rebaixamento do pasto no inverno incrementou o balanço entre TApP e TMoP e o número de perfilhos, em relação à sua manutenção em 25 cm. Houve maiores números de perfilhos reprodutivos e mortos no verão e no inverno, respectivamente. Os pastos com 25 cm possuíram maior número de perfilho morto. Em lotação contínua, o rebaixamento da B. decumbens para 15 cm no inverno e sua manutenção em 25 cm na primavera e verão otimiza sua renovação de perfilhos.The study was conducted to identify, through assessments of tillering, appropriate management strategies for Brachiaria decumbens cv. Basilisk under continuous stocking with cattle. Two management strategies were studied: pasture with 25 cm throughout the experimental period, and pasture with 15 cm in winter and 25 cm in spring and summer. A split-plot and randomized block design with four replications were adopted. The management strategies represented the primary factor, and the seasons (winter, spring and summer were the secondary factor. The lowest balance between rates of appearance (TAR and mortality (TMR of tillers and the lowest number of vegetative tillers occurred in winter

Caracterização de perfilhos de capim-braquiária em locais com três intensidades de pastejo Characterization of signalgrass tiller in sites of same pasture with three grazing intensities

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Guilherme Portes Silva

2010-12-01

Full Text Available Objetivou-se caracterizar a densidade populacional e as características estruturais de perfilhos vegetativos e reprodutivos da Brachiaria decumbens cv. Basilisk manejada sob lotação contínua com bovinos. Os tratamentos foram três locais do mesmo pasto, subpastejado, com pastejo adequado e sobrepastejado. O delineamento foi em blocos casualizados com três repetições. O número de perfilhos basais foi menor nos locais com subpastejo, e maior no local com pastejo adequado. O número de perfilho aéreo foi superior no local com pastejo adequado. No local com superpastejo, o número de perfilho reprodutivo foi inferior, enquanto que os números de perfilhos vegetativos e mortos foram superiores em relação ao local com pastejo adequado. O local subpastejado possuiu perfilhos vegetativos e reprodutivos mais pesados do que os demais locais avaliados. Em locais do mesmo pasto com distintas intensidades de pastejo, a relação entre número e peso de perfilho vegetativo foi negativa, enquanto que a mesma relação para o perfilho reprodutivo foi positiva. Em comparação aos outros locais, no local com superpastejo, os perfilhos possuíram menores comprimentos do pseudocolmo e da lâmina foliar, inferior número de folha morta, maior número de folha pastejada e menor massa de colmo vivo e lâmina foliar viva. Os perfilhos de B. decumbens têm seu número e suas características modificadas em função da intensidade de pastejo a que são submetidos em um mesmo pasto.It were characterized the population density and structural characteristics of vegetative and reproductive tillers of Brachiaria decumbens cv. Basilisk managed under continuous stocking with cattle. The treatments were three sites of the same pasture, undergrazed, with proper grazing and overgrazed. A randomized block design with three replications was used. The number of basal tillers was lower in undergrazed and overgrazed sites, and higher in site with appropriate grazing. The

Nutrient Availability and Changes on Chemical Attributes of a Paleudult Soil Amended with Liquid Sewage Sludge and Cropped with Surinam Grass

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Luiz Carlos Ceolato

2011-01-01

Full Text Available The liquid sewage sludge (LSS was applied on a field experiment during four years at successive applications to evaluate the changes in soil attributes and on Surinam grass (Brachiaria decumbens uptake of nutrients. A randomized blocks experimental design, with two treatments (with and without LSS and three repetitions, was used. Land application of LSS did not alter soil organic matter and exchangeable K until 40 cm depth. However, it increased soil pH, base saturation, labile P, and available Zn and did not change the concentrations of available B (hot water and Cu, Fe, and Mn (DTPA at 0–20 cm and 20–40 cm depths and LSS was a source of N, K, P, Ca, Mg, and Zn for the grass, but decreased leaf Mn concentration.

Efeitos na taxa de transporte de elétrons de plantas daninhas após aplicação de amicarbazone Effects on the electron transport rate of weeds after amicarbazone application

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R Araldi

2011-09-01

Full Text Available Entre os herbicidas registrados para cana-de-açúcar, o amicarbazone é um dos mais importantes para o controle das plantas daninhas, sendo preciso que o herbicida seja absorvido, translocado e que ele alcance os cloroplastos das células das folhas para atuar em seu sítio de ligação no fotossistema II. O objetivo deste trabalho foi avaliar os efeitos da aplicação do amicarbazone na taxa de transporte de elétrons (ETR de Ipomoea grandifolia, Brachiaria decumbens e Digitaria horizontalis. Foi verificada a resposta dessas plantas daninhas, em relação à ETR, quando submetidas ao amicarbazone em solução e na sequência à solução sem herbicida, por meio de leituras da ETR, realizadas em folhas novas e adultas com o uso de um fluorômetro portátil. Verificou-se também o consumo de água das plantas daninhas pela pesagem diária dos recipientes contendo a solução e as plantas. Assim, verificou-se por meio do experimento que a redução dos valores da ETR pode ser utilizada para indicar o nível de intoxicação nas plantas daninhas em estudo. As plantas daninhas I. grandifolia, B. decumbens e D. horizontalis apresentaram respostas diferenciadas quando submetidas a solução sem herbicida após solução com amicarbazone. I. grandifolia apresentou-se mais sensível ao amicarbazone devido à maior dificuldade em recuperar os níveis iniciais de ETR, além de apresentar alterações nas folhas novas após o termino de fornecimento do herbicida. O consumo de água pode explicar esse comportamento em I. grandifolia, visto tratar-se da espécie que mais consumiu água e, consequentemente, mais absorveu o amicarbazone. Já para B. decumbens e D. horizontalis ocorreram menores níveis de absorção de água e, por conseguinte, as folhas velhas tiveram melhor recuperação do transporte de elétrons e não houve intoxicação em folhas novas.Amicarbazone is one of the most important herbicides registered for weed control in sugarcane. It must

Fraccionamiento y cuantificación de la materia orgánica en Andisoles bajo diferentes sistemas de producción

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Juan Carlos Montoya Salazar

2013-12-01

Full Text Available En Andisoles de los municipios de Cajibío, departamento del Cauca y Sevilla, Valle del Cauca, Colombia, se evalúo el efecto del uso del suelo con sistemas de bosque; guadua (Guadua angustifolia K.; cultivo de café (Coffea arabiga var. Caturra a plena exposición, con sombra de guamo (Inga sp. y sombra de nogal (Cordia alliodora; y pastura de brachiaria (Brachiaria decumbens sobre diferentes formas de la materia orgánica (M.O.. Para el efecto en Cauca se tomaron muestras de un Typic Melanudand localizado a 1740 m.s.n.m. utilizado con los cinco primeros sistemas de cultivos, y en Sevilla de un Typic Haplustand en 1660 m.s.n.m en pasturas de brachiaria. Los suelos de ambos sitios fueron caracterizados por sus propiedades físicas (humedad higroscópica, densidad aparente, distribución de partículas, estabilidad de agregados y tamaño de arenas, y químicas (capacidad de intercambio catiónico, pH, % carbono orgánico. Las sustancias húmicas se obtuvieron con extracción secuencial en soluciones (0.1 N de tetraborato, pirofosfato e hidróxido de sodio, previa separación granulométrica por tamizado en húmedo; igualmente se purificaron y caracterizaron los ácidos húmicos y fúlvicos por diferentes técnicas analíticas y espectroscópicas. En ambos suelos, se encontraron diferencias (P 1 en ácidos húmicos y < 1 en fúlvicos. Los ácidos húmicos con mejor grado de condensación se encontraron en el Typic Melanudand.

Suplementação mineral e mobilização de cálcio nos ossos de eqüinos em pastagem de Brachiaria humidicola Effect of mineral supplement on calcium mobilization from bone of equine grazing Brachiaria humidicola

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José Nicolau Prospero Puoli Filho

1999-05-01

Full Text Available Durante 150 dias, 12 potras Quarto-de-Milha de 1 ano de idade permaneceram exclusivamente em pastagem de Brachiaria humidicola, num experimento inteiramente casualizado, com três tratamentos, nível 0 (recomendação do NRC, 1989; nível 50 (50% a mais do NRC; nível 100 (100% a mais do NRC, e quatro repetições. Como palatabilizante foram empregadas 270 g de açúcar. Realizaram-se biópsias na asa do osso do ílio de cada potra, no início e final do experimento, para avaliar a mobilização de Ca e a relação Ca:P. As amostras da gramínea, foram coletadas mensalmente para verificação do teor de oxalato e composição químico-bromatológica. Houve efeito de tempo na mobilização de Ca, P e da relação Ca:P (pDuring 150 days 12 female Quarter Horse yearlings at one year of age were kept solely on Brachiaria humidicola pasture, on a complete randomized design, with three treatments and four replications: level 0 (NRC1989; level 50 (50% above NRC; level 100 (100% above NRC. It was used 270 g of sugar as an intake promoter. Biopsis were perfomed on the wing of ileum of each animal, one at the onset and the other at the end of trial, in order to evaluate Ca mobilization and Ca:P of the bone. Forage samples were collected monthly to evaluate oxalate levels and chemical composition. There was a time effect on Ca mobilization and Ca:P (P< 0.05, regardless the treatments. The average of the three treatments, at the onset and at the end of the trial, for Ca and P levels and Ca:P was, respectively: 10.05, 5.22, 1.93:1 and 6.24, 4.06, 1.54:1. The levels of oxalate in the grass varied from 1.18 to 2.00%. Suplementing Ca to young horses at a level 200% greater than the National Research Council recomendation did not prevent Ca mobilization from the bone when the animals were grazing Brachiaria humidicola for an extended period of time.

Época e densidade de semeadura afetando a produção de Capim Piatã e Brachiaria ruziziensis em consórcio com soja

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Eduardo Andrea Lemus Erasmo

2017-09-01

Full Text Available O sistema de consórcio entre culturas é usado em muitas partes do mundo, em geral, tem se mostrado mais produtivo que o monocultivo. Assim sendo, o presente trabalho tem como objetivo avaliar a densidade e época de semeadura de Brachiária brizantha cv. BRS Piatã e Brachiaria ruziziensis em consorcio com a cultura da soja. O estudo foi conduzido em condições de campo na estação experimental da Universidade Federal do Tocantins. O delineamento experimental utilizado foi em blocos casualizados, em esquema fatorial de (2 x 2 x 3 + 4, com quatro repetições, correspondendo a duas épocas de semeadura da Brachiaria brizantha cv. BRS Piatã e Brachiaria ruziziensis, duas densidades de semeadura da braquiária e a braquiária crescida isoladamente nas duas densidades e épocas testadas. 140 dias após o plantio da soja foram determinados o número de perfilhos, altura, massa seca da parte aérea; massa seca foliar e massa seca do colmo. Os dados foram submetidos à análise variância e as médias comparadas pelo teste Tukey. O cultivo da braquiária em consórcio com a soja promoveu a redução de todos os parâmetros avaliados. O aumento da densidade de semeadura promoveu redução no perfilhamento, e aumento na produção de matéria seca.

Ruminal methane emission by dairy cattle in Southeast Brazil Emissão de metano ruminal por bovinos leiteiros no sudeste do Brasil

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Márcio dos Santos Pedreira

2009-12-01

Full Text Available Ruminal gases, particularly methane, generated during the fermentative process in rumen, represent a partial loss of feed energy and are also pointed to as an important factors in greenhouse effect. This study aimed at quantifying methane (CH4 emission rates from lactating and dry cows and heifers, 24 month-old in average, on pasture under Southeast Brazil tropical conditions, using the tracer gas technique, sulphur hexafluoride (SF6, four animals per category, distributed in four blocks. Measurements were performed in February and June, 2002, with Holstein and Brazilian Dairy Crossbred (Holstein ¾ x Gir (Zebu ¼, maintained on fertilized Tanzania-grass (Panicum maximum Jacq. cv. Tanzania and fertilized Brachiaria-grass (Brachiaria decumbens cv. Basilisk pastures. Heifers of both breeds were maintained on unfertilized Brachiaria-grass to simulate conditions of extensive cattle farming systems. CH4 and SF6 levels were measured with gas chromatography. Differences in CH4 emissions were measured (p Gases gerados durante o processo de fermantação ruminal, metano em particular, representam não só uma perda parcial de energia da alimentação como também são apontados como importantes fatores do efeito-estufa. Quantificaram-se as taxas de emissão de metano (CH4 ruminal por vacas em lactação, vacas secas e novilhas com idade média de 24 meses, em pastejo sob condições tropicais do sudeste brasileiro, utilizando a técnica do gás traçador hexafluoreto de enxôfre (SF6. Foram utilizados quatro animais para cada categoria, distribuídos em quatro blocos. As medições foram realizadas em fevereiro e junho de 2002, com animais da raça Holandesa e Mestiça Leiteira Holandês ¾ x Gir ¼ - Mestiças, mantidos em pastagem de capim-Tanzânia (Panicum maximum Jacq. cv. Tanzania e capim-braquiária (Brachiaria decumbens cv. Basilisk adubadas, e também novilhas de ambas as raças em pastagens de capim-brachiaria sem adubação, simulando as condi

Effect of doses of poultry compost on chorophyll and flavonoids of Brachiaria brizantha brs Piatã

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Alexandre Antonio Pasqualini

2013-12-01

Full Text Available In 2012, Brazil produced 12.6 million metric tons of chicken meat, generating 10.3 tons of poultry litter. Compost made from such organic waste can be used as a low-cost bio fertilizer, especially as nitrogen and phosphorus source. The compost can increase pastures quality by giving photosynthetic improvement and altering amounts of chlorophyll and flavonoids.  There is little information about the relationship between chlorophyll a or b and flavonoids in Brachiaria brizantha Piata. The flavonoid is a kind of polyphenol compound which protects the plant against UV-B radiation and pathogen attack, it acts as attractants for pollinators, as signal molecules for initiating plant-microbe symbiotic associations and antioxidant activity. The objective of the present study was verified the effects of poultry litter compost doses on the chlorophyll and flavonoid contents in Piata grass leaves. The experiment was performed at the Animal Nutrition and Pasture Center – Instituto de Zootecnia – Nova Odessa, SP, from May to July 2013, on a Haplorthox soil (pHCaCl2= 4.9, cultivated with Piata grass (Brachiaria brizantha, Stapf, without liming. The treatments consisted of five compost doses: 0; 20; 40; 60 and 120 Mg ha-1, with the following chemical composition (%: 2.88 of N, 3.85 of P2O5, 2.50 of K2O, 9.06 of Ca and 1.16 of Mg. The experimental design was on randomized blocks with five replications.  Chlorophyll amounts and flavonoids were determined by sampling the third medium of the leaf blade from  a third of the expanded leaf from the apical  using the Dualex and the chlorophyll a and b  which were determined by  the Lichtenthaler & Wellburn (1983 method.  Results showed that chlorophyll a was similar in all doses (average of 18.3 micrograms per cm2,therefore for chlorophyll b the amount was significantly increased from 7.3 to 22.4 micrograms per  cm2 (P<0.01when compared to no addition of poultry litter. The fast nitrogen liberation from

Rumen dynamics of neutral detergent fiber in cattle fed low-quality tropical forage and supplemented with nitrogenous compounds Dinâmica ruminal da fibra em detergente neutro em bovinos alimentados com forragem tropical de baixa qualidade e suplemento com compostos nitrogenados

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Cláudia Batista Sampaio

2009-03-01

Full Text Available The aim of this work was to evaluate the effects of supplementation with nitrogenous compounds on rumen dynamics of neutral detergent fiber (NDF in cattle fed low-quality tropical forage. Five crossbred heifers with average live weight of 180 kg and fitted with rumen cannulae were used. The animals were fed ad libitum with signal grass (Brachiaria decumbens Stapf. hay, which had crude protein (CP content of 4.86% of dry matter (DM. The five treatments were proposed in order to raise the CP level of diets to 0, 2, 4, 6, and 8 percentile points above the CP level of the forage. The supplement was a mixture of urea, ammonium sulfate, and albumin (4.5:0.5:1.0, respectively. The experiment was carried out according to a 5 × 5 Latin square design, with five experimental periods. The average CP levels in the diets were: 5.19, 7.11, 8.60, 11.67, and 13.02% on DM basis. The potentially degradable NDF was linearly increased according to the CP levels in diet up to 6.97% of CP. From this point, there was stabilization of estimates (47.87% of NDF. The degradation rate of potentially degradable NDF was linearly increased with the CP levels in diets. The rumen flow of fibrous particles (L showed a linear-response-plateau pattern according to the CP levels in diets. The plateau (maximum estimate began on 7.24% of CP. The mean retention time in the rumen and the rumen fill effect of undegradable NDF were affect by the CP levels similarly to L, with plateau (minimum beginning on 6.90 and 6.97% of CP, respectively.Objetivou-se avaliar os efeitos da suplementação com compostos nitrogenados sobre a dinâmica ruminal da fibra em detergente neutro (FDN em bovinos alimentados com forragem tropical de baixa qualidade. Foram utilizadas cinco novilhas mestiças Holandês × Zebu, com peso vivo médio inicial de 180 kg, fistuladas no rúmen. A alimentação volumosa basal dos animais foi constituída por feno de capim-praquiátia (Brachiaria decumbens Stapf (4,86% de

Consumo e digestibilidade da matéria seca de fenos de braquiária decumbens e amendoim forrageiro em ovinos estimados por meio de n-alcanos Use of n-alkanes to estimate intake and digestibility of signalgrass and forage peanut in sheep

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Nelson Massaru Fukumoto

2007-04-01

of particular interest to compare two methodologies of fecal collection (total collection vs. grab samples as well as to identify which n-alkanes best estimate DMI and DM digestibility. Twenty animals were assigned to a completely randomized design and were fed diets containing different proportions of forage peanut (Arachis pintoi Koprov & Gregory cv. Amarillo and signalgrass hays [Brachiaria decumbens, (Stapf, Webster] (0, 15, 30, 45 and 60% of forage peanut; DM basis. The experiment lasted 18 days with 10 days for diet adaptation, three days for marker administration (C32 in cellulose pellets, and five days for fecal collection. Data were submitted to analysis of variance and observed and estimated means were compared by t test. Fecal grab samples were collected six times daily at 4 hours intervals (9:00, 13:00, 17:00, 21:00, 01:00 and 05:00 for five consecutive days. The internal alkanes C31, C33, and C31 + C33 were used for estimating DMI while DM digestibility was estimated by C33, C35, and C33 + C35. Results showed that reliable estimation of DM digestibility was obtained by using the internal alkane C33 corrected for fecal recovery. The combination of the internal alkanes C31 + C33 resulted in the best estimation of DMI with no need for fecal recovery correction. In addition, only one daily fecal grab sample (9 h or 13 h was necessary to accurately estimate DMI.

Aleloquímico produzido pela gramínea forrageira Brachiaria humidicola Allelochemical produced by the forage grass Brachiaria humidicola

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A.P.S. Souza Filho

2005-03-01

Full Text Available Os métodos usuais de controle de plantas daninhas não atendem mais as atuais e futuras exigências da sociedade em relação à preservação dos recursos naturais e da qualidade de vida. Uma alternativa para essa questão seriam os metabólitos secundários produzidos pelas plantas, que apresentam pouco risco para o ambiente e para os interesses da sociedade. Os objetivos deste trabalho foram isolar, identificar e caracterizar a atividade alelopática de substâncias químicas produzidas pela gramínea forrageira Brachiaria humidicola. Analisaram-se os efeitos alelopáticos dos extratos, frações e substâncias isoladas sobre a germinação e o desenvolvimento da radícula das invasoras malícia, fedegoso e mata-pasto, em bioensaios monitorados em períodos de 10 dias, em condições de 25 ºC e fotoperíodo de 12 horas, para a germinação, e 24 horas, para o desenvolvimento da radícula. A partir do extrato hidrometanólico, foi isolado e identificado o ácido p-cumárico. Os efeitos alelopáticos estiveram positivamente relacionados à concentração do ácido, à espécie de planta daninha e à característica da espécie analisada. Comparativamente, fedegoso e malícia se mostraram mais sensíveis aos efeitos alelopáticos. A germinação e o desenvolvimento da radícula do mata-pasto não foram afetados pelo ácido p-cumárico nas concentrações de 1,0 a 8,0 mg L¹. O alongamento da radícula se mostrou mais sensível aos efeitos alelopáticos do ácido pcumárico do que a germinação das sementes.The traditional methods of weed control in cultivated pasture do not meet society's present and future needs of protecting natural resources and life quality. An alternative to this problem could be the use of secondary metabolites produced by plants. These products present few risks to the environment and meet society interests. Therefore, this research was carried out to isolate, identify and characterize the allelopathic activity of

Intoxicações por plantas em ruminantes e equídeos na região central de Rondônia Plant poisonings in ruminants and equidae in central region of Rondônia state, Northern Brazil

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Sandro Vargas Schons

2012-07-01

Full Text Available Foi realizado um levantamento em 12 municípios da região central de Rondônia sobre a presença de plantas tóxicas e ocorrência de surtos de intoxicação em ruminantes e equídeos. O trabalho foi desenvolvido mediante a utilização de um questionário aplicado a médicos veterinários, agrônomos, zootecnistas e produtores rurais, com o objetivo de identificar as principais plantas tóxicas que ocorrem na região. Trinta e quatro entrevistados relataram casos de intoxicação por uma ou mais plantas comprovadamente tóxicas como: Palicourea marcgravii (12 surtos, Palicourea grandiflora e Enterolobium contortisiliquum (sete surtos cada e Palicourea juruana, Brachiaria radicans, Brachiaria brizantha e Manihot esculenta (dois surtos cada. Em ovinos, foram relatados dois surtos de fotossensiblização por Brachiaria decumbens e um surto de mortalidade por Palicourea grandiflora. Dos 34 surtos relatados em bovinos pelos entrevistados, 374 (8,9% animais foram afetados e 311 (7,4% morreram, de um total de 4.192 de ambos os sexos sob risco. De um total de 250 ovinos sob risco, três surtos de intoxicação por plantas foram relatados e afetaram 28 animais, dos quais 20 morreram. Amorimia sp., previamente desconhecida como tóxica, foi identificada como causa de morte súbita em 32% das propriedades. Quinze surtos de cólica em equídeos que pastavam cultivares de Panicum maximum ('Massai', 'Tanzânia' e 'Mombaça' durante o período das chuvas foram, também, observados. Os resultados do presente trabalho demonstram a importância significativa das intoxicações por plantas como causa de perdas econômicas para a pecuária da região central do Estado de Rondônia. Com a realização deste trabalho, o número de plantas tóxicas para ruminantes com a confirmação de ocorrência de surtos com mortalidade na região passou de um para nove, o que confirma que um trabalho sistemático de investigação é necessário para o conhecimento da import

Desempenho de pontas de pulverização em Brachiaria brizantha cv. MG-4 para controle de ninfas de cigarrinhas das pastagens Spray nozzles performance in Brachiaria brizantha cv. MG-4 for pastures spittlebugs nymphs control

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Cleber D. de G. Maciel

2007-01-01

Full Text Available O trabalho teve como objetivo estudar o desempenho de pontas de pulverização na deposição da calda inseticida para o controle de ninfas de cigarrinhas das pastagens em Brachiaria brizantha cv. MG-4. Doze tratamentos foram estudados em esquema fatorial 6x2, constituídos pelo contraste de seis pontas de pulverização e pressões de 196 e 392 kPa: TF-VP2 (336 L ha-1 e 467 L ha-1; AI11002-VS (184 L ha-1 e 200 L ha-1; XR11002-VS (200 L ha-1 e 280 L ha-1; TT11002-VP (200 L ha-1 e 280 L ha-1; TJ60-11002VS (208 L ha-1 e 280 L ha-1 e TX-VK4 (72 L ha-1 e 97 L ha-1. Para monitorar a deposição das caldas de pulverização, utilizaram-se os traçadores Azul Brilhante FD&C-1 (0,3% p/v e Amarelo de Tartrasina FD&C-5 (0,6% p/v. Alvos artificiais, constituídos de lâminas de vidro, foram posicionados na base das plantas, próximos à superfície do solo, e os depósitos por unidade de área das soluções pulverizadas foram quantificados por espectrofotometria. As pontas TF-VP2, XR11002-VS e AI11002-VS, nas pressões de 196 e 392 kPa, proporcionam as maiores deposições da calda de pulverização na região das espumas das cigarrinhas das pastagens, apesar de apresentarem menor uniformidade na distribuição dos depósitos em relação a TX-VK4, XR110.02-VS e TJ110.02-VS. O aumento da pressão de 196 para 392 kPa promoveu aumento na deposição da calda de pulverização sobre a Brachiaria brizantha e na região onde se encontram as espumas das cigarrinhas para todos os tipos de pontas estudadas.The work aimed to study spray nozzles performance in pesticide sprayer deposition for controlling pastures spittlebugs nymphs in Brachiaria brizantha cv. MG-4 pasture. Twelve treatments were studied in factorial scheme 6x2, constituted by the contrast of six spray nozzles and 196 and 392 kPa work pressures: TF-VP2 (336 L ha-1 and 467 L ha-1; AI11002-VS (184 L ha-1 and 200 L ha-1; XR11002-VS (200 L ha-1 and 280 L ha-1; TT11002-VP (200 L ha-1 and 280 L ha¹; TJ60

EVALUACIÓN DE LA BIOACUMULACIÓN Y TOXICIDAD DE CADMIO Y MERCURIO EN PASTO LLANERO (Brachiaria dictyoneura)

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ARROYAVE Q, Catalina; ARAQUE M, Pedronel; PELAEZ J, Carlos A

2010-01-01

Se estudia la transferencia de mercurio y cadmio desde el sistema suelo hacia Brachiaria dictyoneura en función de la capacidad bioindicadora y bioacumuladora. Durante la evaluación de cadmio en B. dictyoneura se observó una disminución en el crecimiento del 65%. La toxicidad de cadmio se correlaciona con la acumulación consecutiva del catión durante el tiempo de monitoreo. En el tratamiento con mercurio, a partir de los 30 días de exposición, se observó disminución en el contenido del catión...

Avaliação de métodos para recuperação de pastagens de braquiária no agreste de Pernambuco: 1. aspectos quantitativos Evaluation of methods to recovery degraded pastures of Brachiaria in the agreste region of Pernambuco State: 1. quantitative aspects

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Maria da Conceição Silva

2004-12-01

Full Text Available O experimento foi realizado com o objetivo de avaliar a resposta produtiva de uma pastagem degradada de Brachiaria humidicola (Rendle Schweickt sob diferentes métodos de recuperação. O delineamento experimental foi blocos ao acaso com confundimento e em parcelas subdivididas, sendo a parcela principal representada pela combinação dos manejos com os níveis de adubação e as subparcelas pelos períodos de diferimento. Os tratamentos experimentais foram constituídos de quatro manejos de recuperação (sem preparo do solo, gradagem, gradagem + milho, plantio direto do milho, dois níveis de nitrogênio (0 e 100 kg de N/ha, dois níveis de fósforo (0 e 100 kg de P2O5/ha e diferentes períodos de diferimento (113, 156, 200 e 240 dias, perfazendo 64 tratamentos, com três repetições. Houve interação entre sistemas de manejo e a adubação fosfatada, sendo obtidos acúmulo de matéria seca (AMS médios de 7,52; 1,68; 1,10 e 4,43 t/ha de B. humidicola, para o sistema sem preparo do solo, gradagem, gradagem + milho e plantio direto do milho, respectivamente. O maior período de diferimento elevou AMS, altura de planta, a participação da braquiária no AMS e diminuiu a participação de outras espécies (% no AMS e a área de solo descoberto (%. Pastagens de B. humidicola em início de degradação cultivada em solo com baixa disponibilidade de fósforo podem ser recuperadas com um período de descanso associado à adubação fosfatada.The experiment was performed to evaluate the productive response of a degraded B. humidicola pasture to different pasture recovery methods. It was used a split-plot within a confounded randomized block design. The main plot was represented by the combination among managements and fertilization levels and the sub-plot by the deferred periods. The experimental treatments were four recovery managements (no-tillage, harrowing, harrowing + corn as a companion crop, no-tillage + corn as a companion crop, two levels

Progresso e controle da mela-das-sementes (Claviceps maximensis de Brachiaria brizantha Progress and control of honeydew (Claviceps maximensis of Brachiaria brizantha

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Carlos Eduardo Marchi

2008-09-01

Full Text Available Verificou-se a eficiência de uma ou duas aplicações de Piraclostrobin + Epoxiconazole, Mancozeb, Triadimenol, Azoxistrobin + Ciproconazole, Trifloxistrobin + Ciproconazole ou Tebuconazole no controle da mela-das-sementes de Brachiaria brizantha cvs. Marandu e Xaraés, durante a safra 2004-05. Também foram avaliados os indutores de resistência Acibenzolar-S-Metil e Silicato de Potássio (via aérea ou solo. Triadimenol, com uma ou duas aplicações, Piraclostrobin + Epoxiconazole, Azoxistrobin + Ciproconazole, Trifloxistrobin + Ciproconazole ou Tebuconazole, com duas aplicações, foram promissores no controle da mela-das-sementes do capim-marandu. Já para a cv. Xaraés, melhor controle foi alcançado com o Piraclostrobin + Epoxiconazole, independente do número de aplicações, Triadimenol, Trifloxistrobin + Ciproconazole ou Tebuconazole, com duas aplicações. Não houve correlação entre os dados de produção de sementes puras e a intensidade da mela. Com relação ao progresso da mela-das-sementes de B. brizantha cvs. Marandu e Xaraés, constatou-se que a doença manifestou-se em períodos frios associados à umidade relativa alta. Na cv. Marandu a doença ocorreu na fase final da cultura, enquanto que na cv. Xaraés, a mela foi detectada na fase de intenso florescimento. Foram constatados aumentos na intensidade da doença em ambas as cultivares. A mela-das-sementes ocorreu em 64% das panículas da cv. Marandu e em 81% das panículas da cv. Xaraés; cerca de 20% e 18% das flores/sementes, respectivamente, foram afetadas. Os resultados demonstraram existir correlação positiva entre os valores de incidência e severidade da mela.The efficiency of one or two applications of Pyraclostrobin + Epoxyconazole, Mancozeb, Triadimenol, Azoxystrobin + Cyproconazole, Trifloxystrobin + Cyproconazole or Tebuconazole in the control of honeydew in seeds of Brachiaria brizantha cvs. Marandu and Xaraes was verified during crop 2004-05. The inductors

STRAW DEGRADATION AND NITROGEN RELEASE FROM COVER CROPS UNDER NO-TILLAGE

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ADRIANO STEPHAN NASCENTE

2014-01-01

Full Text Available Culturas de cobertura são usadas para cobrir o solo e também podem liberar nitrogênio para o solo durante a mineralização. No entanto, é necessário identificar espécies que combinem liberação rápida de nutri- entes com maior persistência da palhada na superfície do solo. O objetivo deste estudo foi investigar a degrada- ção da palha e a liberação de nitrogênio por culturas de cobertura sob plantio direto. O experimento de campo foi conduzido durante dois anos no verão (2008/2009 e 2009/2010 na região do Cerrado do Brasil. O delinea- mento experimental foi em blocos ao acaso no esquema fatorial. Os tratamentos foram a combinação de cinco plantas (quatro espécies de plantas de cobertura 1- Panicum maximum, 2- Brachiaria ruziziensis, 3- Brachiaria brizantha e 4- Pennisetum glaucum [milheto] e pousio como controle com seis épocas de avaliação (seis pri- meiras semanas após a aplicação de glifosato nessas plantas de cobertura. Entre as espécies avaliadas, Penise- tum glaucum e pousio tiveram rápida degradação da palhada e liberação de nitrogênio. As culturas de cobertura Panicum maximum, Brachiaria brizantha e Brachiaria ruziziensis se destacaram na produção de biomassa e na quantidade de nitrogênio nas suas palhadas, mas apresentaram baixos coeficientes de degradação e persistiram por mais tempo na superfície do solo em relação a Pennisetum glaucum e pousio.

Valor nutritivo da forragem e produção animal em pastagens de Brachiaria brizantha Forage nutritive value and animal production in Brachiaria brizantha pastures

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Valéria Pacheco Batista Euclides

2009-01-01

Full Text Available O objetivo deste trabalho foi avaliar a produção animal e sua relação com as características dos pastos de Brachiaria brizantha cultivares Marandu, Xaraés e Piatã. O delineamento experimental foi o de blocos ao acaso, com três tratamentos e duas repetições. Os piquetes com 2 ha foram subdivididos em dois e submetidos ao pastejo alternado, com 28 dias de utilização e 28 dias de descanso. Foram utilizados três novilhos teste, por piquete, e novilhos reguladores para manter resíduos pós pastejo em torno de 3 Mg ha-1 de matéria seca. Mensalmente, os pastos foram avaliados para se estimar o valor nutritivo da forragem. Os animais foram pesados, e as taxas de lotação foram ajustadas duas vezes por semana. No pasto da cv. Xaraés, apesar do menor ganho médio diário (GMD dos animais, a taxa de lotação foi maior, o que resultou em maior produtividade da cv. Xaraés, em comparação às cvs. Marandu e Piatã. No pasto da cv. Piatã, houve aumento do GMD, o que indica que as cvs. Xaraés e Piatã são novas alternativas para a diversificação dos pastos no Cerrado. Assim, a escolha da forragem deve se dar em razão da meta do sistema de produção, ou seja, a produção por animal ou por área.The objectives of this work were to evaluate animal production and its relationship with pasture characteristics of Brachiaria brizantha cultivars Marandu, Xaraés and Piatã. The experiment had a randomized complete block design, with three treatments and two replicates. Two-ha paddocks were divided into two and submitted to alternated grazing, with 28 days of grazing and 28 days of rest. Three tester steers were kept in each paddock; additional steers were placed in each paddock by the put and take technique, to assure post grazing residues of about 3 Mg ha-1 of dry matter. The pastures were sampled monthly to estimate the nutritive value of the forage. The animals were weighted, and the stocking rate was adjusted twice a week. Despite the

Seletividade do oxyfluorfen para a cultura do pinhão-manso Selectivity of oxyfluorfen for physic nut culture

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K.S Gonçalves

2009-12-01

Full Text Available Realizou-se um experimento para avaliar a seletividade do oxyfluorfen para a cultura do pinhão-manso. Foi utilizado o delineamento experimental inteiramente casualizado, com cinco repetições, em esquema fatorial 2 x 2 + 1, sendo duas doses do herbicida (600 e 1.200 g ha-1 do ingrediente ativo, dois modos de aplicação (sobre a planta e sobre o solo e uma testemunha sem aplicação do herbicida. Após o transplante das mudas para vasos plásticos com 10 litros de solo, os tratamentos foram aplicados com o auxílio de um balde. O oxyfluorfen, quando aplicado sobre as plantas, mostrou-se tóxico nas duas doses testadas, sendo observados sintomas mais intensos nos primeiros dias após a aplicação dos tratamentos. Após esse período, as mudas recuperaram o vigor e surgiram novas brotações que não apresentavam sintomas de toxicidade. Esses sintomas consistiram de manchas esbranquiçadas nas folhas, que evoluíram para necrose. Nas mudas em que o herbicida foi aplicado no solo, não foram observados sintomas visuais de toxicidade. Observou-se redução na massa fresca e seca das folhas quando 600 g ha-1 do herbicida foram aplicados sobre a planta ou 1.200 g ha-1 sobre o solo. Contudo, a área foliar e o número de folhas não diferiram significativamente entre as doses utilizadas e os modos de aplicação. Das quatro espécies daninhas semeadas (Brachiaria decumbens, Brachiaria plantaginea, Sida rhombifolia e Bidens pilosa, apenas Bidens pilosa não foi controlada pelo oxyfluorfen aplicado em pré-emergência.An experiment was carried out to evaluate the selectivity of oxyfluorfen for physic nut culture. The experiment was arranged in a completely randomized design with five replications in a factorial 2 x 2 + 1, two herbicide doses (600 and 1,200 g ha-1 of active ingredient, two modes of application (on the plant and soil and a control without herbicide application.. After transplanting the seedlings into plastic pots with 10 liters of soil

PHYTOSOCIOLOGY OF SOWN PASTURE WEEDS UNDER TWO LEVELS OF DEGRADATION IN BRAZILIAN SAVANNA AREAS, MATO GROSSO DO SUL STATE, BRAZIL FITOSSOCIOLOGIA DE PLANTAS DANINHAS DE PASTAGENS CULTIVADAS SOB DOIS NÍVEIS DE DEGRADAÇÃO EM CERRADO, NO MATO GROSSO DO SUL

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Adriana Guglieri-Caporal

2010-08-01

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Cultivated pastures, in general, go through a decline process, associated with the occurrence of weeds, whose successful management begins with the survey of species and their biology. This study aimed to carry out phytosociological surveys, during the rainy and dry seasons, in two pastures cultivated with Brachiaria (Urochloa spp., with cattle (AI and without cattle (AII, in Cerrado (Brazilian savanna areas of the Mato Grosso do Sul State, Brazil. The occurrence of 104 weedy herbaceous and subshrubby Phanerogams species was recorded. The families with the highest number of species were Fabaceae (23 species, Poaceae (16, and Asteraceae (15. Hemicryptophytes predominate with 41% of the species. The species with the highest importance value and relative coverage are B. decumbens and Sida rhombifolia, in AI, and B. brizantha and Desmodium incanum, in AII, plus Paspalum notatum, in both pastures. The Shannon diversity index was 4.19 and 4.43 nats, for AI and AII, respectively, indicating considerable weed species richness. The floristic dissimilarity index between AI and AII, obtained from the Euclidian

Suplementação volumosa de bovinos Holandês/Zebu em pastagem de Brachiaria decumbens Stapf.

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José Carlos Nunes

2009-01-01

Foram conduzidos dois experimentos na Estação Experimental, pertencente ao Instituto Agronômico de Pernambuco IPA, localizada no município de Itambé. O primeiro experimento foi realizado no período de julho de 2006 a fevereiro de 2007 com os objetivos de caracterizar o pasto, estimar o consumo de forragem e avaliar o efeito da suplementação volumosa de quatro clones de Pennisetum sp. (IRI-381, Venezuela,Elefante B e Hexaploide), colhidos, triturados e fornecidos no cocho, sobre o ganho de pe...

Organic matter fractions in areas Oxisol under different management systems in Cerrado the State of Goiás, Brazil

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Roni Fernandes Guareschi

2013-12-01

Full Text Available The objective of this study was to evaluate the physical and chemical fractions of soil organic matter (SOM, as well as perform the spectroscopic analysis in ultraviolet-visible humic acid in a Oxisol under no-tillage system (NTS with different years of implementation, and compare them to areas of native cerrado and pasture. Was evaluated five areas namely: native cerrado (CE, planted pasture (PA with Brachiaria decumbens; NTS with 3 (NTS 3 years of implementation; NTS with 15 years (NTS 15 of implementation and NTS with more than 20 (NTS 20 years of implementation. The levels and total carbon stocks and humic fractions of SOM, increased with deployment time the NTS at all depths analyzed, with the humic fractions presented the following order: fraction fulvic acid > fraction humic acid > humin fraction. The results showed that depending on the time of implementation of the NTS was observed an increase of more stable fractions of humic substances and physical fractions of SOM, providing greater stability of this system. There is increasing the E4/E6 ratio of humic acids according on the time of implementation of the NTS, demonstrating an increase of aliphatic structures. The area evaluated PA had the lowest concentrations and inventories of humic fractions, carbon associated with minerals (CAM and E4/E6 ratio, demonstrating to be in an advanced stage of degradation relative to the other areas assessed.

Inquérito epidemiológico sobre plantas tóxicas das mesoregiões Central e Oeste do Rio Grande do Norte

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Severino Antonio Geraldo Neto

2013-07-01

Full Text Available Foi realizado um estudo para determinar as plantas tóxicas incriminadas como de interesse zootécnico em 35 municípios das mesorregiões Central e Oeste do estado do Rio Grande do Norte (RN. Foram entrevistados 180 produtores, 20 médicos veterinários, 12 técnicos agrícolas e 5 agrônomos. Os dados obtidos nas entrevistas foram compilados e analisados com auxílio do programa Epi Info versão 6.04. As plantas tóxicas relatadas pelos entrevistados como causadoras de diversos surtos foram Ipomoea asarifolia, Aspidosperma pyrifolium, Indigofera suffruticosa, Manihot carthaginensis subsp. glaziovii, Amorimia septentrionalis, Tephrosia cinerea, Anadenanthera colubrina var. cebil, Marsdenia megalantha, Anacardium occidentale, Cnidoscolus quercifolius, Crotalaria retusa, Froelichia humboldtiana, Ipomoea carnea, Leucaena leucocephala, Manihot esculenta, Mimosa tenuiflora, Nerium oleander, Prosopis juliflora, Ricinus communis, Sorghum bicolor, Sorghum halepense e Urochloa (Brachiaria decumbens.

Limestone doses affecting mineral contents in tropical grass forage

International Nuclear Information System (INIS)

Armelin, M.J.A.; Saiki, M.

2005-01-01

Field trial was performed at the experimental farm of Southeast Embrapa Cattle, Sao Carlos - SP, Brazil, on a 16 year old Brachiaria decumbens pasture, grown on a distrophic Hapludox (Oxisol), recovered by the use of limestone and fertilizer. The experiments were carried out in random blocks, with 6 replications and 5 treatments. The 100 m 2 blocks were established in the pasture. Each block received a sequence of limestone doses of 0, 1, 2, 4 and 8 t/ha. The forage samples were taken one year after limestone application on soil surface. Instrumental neutron activation analysis (INAA) followed by gamma-ray spectrometry was the analytical method used to determine mineral contents. The statistical analysis showed a negative linear correlation of Br, Co, Cr, Mn and Zn contents in forage with the limestone doses, while the uptake of Mg was affected in a positive way. (author)

Demografia e densidade de perfilhos de capim-braquiária sob pastejo em lotação intermitente

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Jorge Nunes Portela

2011-03-01

Full Text Available O objetivo deste trabalho foi avaliar os efeitos de intensidades de pastejo e de frequências de desfolha na demografia e densidade de perfilhos de capim-braquiária (Urochloa decumbens syn. Brachiaria decumbens sob lotação intermitente. Foram avaliados duas intensidades de pastejo (5 e 10 cm de altura pós-pastejo e duas frequências de desfolha (período de descanso até que o dossel atingisse 95 e 100% de interceptação luminosa, IL, de agosto de 2007 a agosto de 2008. Utilizou-se o delineamento inteiramente casualizado, em arranjo fatorial com quatro repetições. Avaliaram-se as densidades populacionais e as taxas de aparecimento e sobrevivência de perfilhos basais (DPPb, TAPb e TSPb, respectivamente e aéreos+basais (DPPab, TAPab e TSPab. As maiores TAPb e TAPab, no outono, foram obtidas nos pastos desfolhados a 10 cm. Porém, no final da primavera e no verão, a intensidade de 5 cm resultou em maiores taxas, que promoveram maior DPPb. No verão, a TSPb foi maior para pastos manejados à intensidade de 10 cm. O manejo da pastagem que resulta em maiores DPPab, TAPab e TSPab, durante as épocas de rápido crescimento dos pastos, é o de 10 cm de intensidade de pastejo e 95% de IL de frequência de desfolha.

Sward characteristics and performance of dairy cows in organic grass-legume pastures shaded by tropical trees.

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Paciullo, D S C; Pires, M F A; Aroeira, L J M; Morenz, M J F; Maurício, R M; Gomide, C A M; Silveira, S R

2014-08-01

The silvopastoral system (SPS) has been suggested to ensure sustainability in animal production systems in tropical ecosystems. The objective of this study was to evaluate pasture characteristics, herbage intake, grazing activity and milk yield of Holstein×Zebu cows managed in two grazing systems (treatments): SPS dominated by a graminaceous forage (Brachiaria decumbens) intercropped with different leguminous herbaceous forages (Stylosanthes spp., Pueraria phaseoloides and Calopogonium mucunoides) and legume trees (Acacia mangium, Gliricidia sepium and Leucaena leucocephala), and open pasture (OP) of B. decumbens intercropped only with Stylosanthes spp. Pastures were managed according to the rules for organic cattle production. The study was carried out by following a switch back format with 12 cows, 6 for each treatment, over 3 experimental years. Herbage mass was similar (P>0.05) for both treatments, supporting an average stocking rate of 1.23 AU/ha. Daily dry matter intake did not vary (P>0.05) between treatments (average of 11.3±1.02 kg/cow per day, corresponding to 2.23±0.2% BW). Milk yield was higher (P0.05) in subsequent years. The highest (P0.05) milk yields. Low persistence of Stylosanthes guianensis was observed over the experimental period, indicating that the persistence of forage legumes under grazing could be improved using adapted cultivars that have higher annual seed production. The SPS and a diversified botanical composition of the pasture using legume species mixed with grasses are recommended for organic milk production.

Comparative effect of selenium and selenium tolerant microbes on brachiaria reptans l. growth

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Yasin, M.; Faisal, M.

2014-01-01

Brachiaria reptans L. is an annual grass. It is good fodder grass which is distributed in tropical Asia, Kenya, Pakistan and India and introduced throughout the tropics. In present study we determine the growth correlation among B. reptans, selenium (Se) and two Se tolerant bacteria (Bacillus licheniformis-YAP7 and Bacillus cereus-YAP6). Plants treated with Se showed a significant decrease in shoot length (33%) and fresh biomass (41%) compared to control. When plants were co-cultivated in the presence of bacteria or Se and bacteria both the shoot length increased (16-34%) significantly compared to control. B. reptans plants treated with Se have shown a significant decrease in peroxidase contents (59%) compared to control. However, bacterial inoculation of Se treated plants resulted in significant increase in peroxidase contents (113-171%). Selenium treatment caused increase in leaf soluble protein contents compared to control. In conclusion, bacteria can enhance B. reptans growth under Se stress. (author)

Retenção do fósforo de fenos de gramíneas tropicais em ovinos Phosphorus balance in sheep fed on tropical grass hays

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R.A. Reis

1999-06-01

Full Text Available Mediu-se a retenção do fósforo de quatro gramíneas tropicais, capim-gordura (Melinis minutiflora, capim-braquiária (Brachiaria decumbens, capim-coastcross (Cynodon dactilon e capim-colonião (Panicum maximum, em cinco ovinos por meio de ensaios de balanço de fósforo. O experimento constou de quatro fases, cada uma com duração de 21 dias (14 dias de adaptação à dieta e sete dias de colheita de fezes, totalizando 20 observações. A análise dos dados foi feita por polinômios ortogonais, testando-se os efeitos de tratamento, de período e de animal, e os contrastes foram comparados pelo teste F. A retenção de fósforo foi negativa nos fenos dos capins gordura, braquiária e coastcross e positiva no feno do capim-colonião. Por análise de regressão, a perda fecal do fósforo endógeno foi estimada em 15,5mg/kg PV/dia e o coeficiente médio de retenção foi de 0,37. Pela razão entre o balanço e a ingestão, estimou-se que o consumo de fósforo necessário para alcançar o equilíbrio foi de 44mg/kg PV/dia.One experiment was conducted using five adult sheep fed on four tropical grass hays to determine phosphorus (P retention. The experiment consisted of four periods of 21 days (14 days adaptation and seven days faeces collection. The treatments were: A molasses grass (Melinis minutiflora, B brachiaria grass (Brachiaria decumbens, C coastcross grass (Cynodon dactilon and D Guinea grass (Panicum maximum. Phosphorus concentrations were 0.05%, 0.07%, 0.11% and 0.18% for treatments A, B, C and D, respectively. The effects of treatment, period and animal were evaluated by ortogonal polynomials and the contrasts by F test. Negative P balances were produced in treatments A, B and C (-13.05, -9.36 and -8.26mg/kg LW/day, respectively which were not significantly different from each other. Positive P balance of 8.14mg/kg LW/day was produced in treatment D, which was significantly higher (P<0.05 than treatments A, B and C. Endogenous losses

THE LEVELS OF SELENIUM IN CERRADOS PASTURES AND THE EFFECTS OF ITS SUPPLEMENTATION IN PERFORMANCE OF LAMBS NÍVEIS DE SELÊNIO EM PASTAGENS DE CERRADO E EFEITOS DA SUPLEMENTAÇÃO SOBRE O DESEMPENHO DE CORDEIROS

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José Henrique Stringhini

2007-09-01

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This experiment was carried out in the Água Limpa Farm, of the University of Brasília, aiming to estimate the level of selenium and its variation during the year in some cultivated pastures of the cerrados region (Andropogon gayanus var. bisquamulatus, Brachiaria decumbens and Brachiaria ruziziensis. On the other hand, it was determined the effects of the supplementation, through intramuscular applications, in 24 Bergamacia weaned lambs. Pastures samples were collected trying to simulate the animal grazing, at intervals of 84 days, and different chemical methods of determination of selenium were evaluated. The fluorometric method has the best response and the levels of the samples varied from 0.025 to 0.075 ppm. In relation to the lambs, difference in weight gains were not statistically significant (P>0.05.

KEY-WORDS: Brazilian savannas (“cerrados”; sheep; selenium supplementation.

O presente experimento foi conduzido na Fazenda Água Limpa, da Universidade de Brasília, e teve como objetivos verificar os níveis estacionais de selênio encontrados nas pastagens de Andropogon gayanus var. bisquamulatus, Brachiaria decunbens e Brachiaria ruziziensis e avaliar os efeitos da suplementação de selênio por via intramuscular em 24 ovinos desmamados da raça Bergamácia. Foram efetuadas quatro coletas de forragem procurando imitar o pastejo dos animais e testados os métodos químicos para análise de selênio. O método fluorométrico foi o mais adequado e determinaram-se os níveis que variaram entre 0,025 e 0,075 ppm para as pastagens estudadas. Com relação aos cordeiros, não se observou efeito significativo para o ganho de peso dos cordeiros (P>0

QUALIDADE FISIOLÓGICA DE SEMENTES DE Brachiaria E AVALIAÇÃO DA PRODUTIVIDADE DE MASSA SECA, EM DIFERENTES SISTEMAS DE INTEGRAÇÃO LAVOURA-PECUÁRIA SOB IRRIGAÇÃO PHYSIOLOGICAL QUALITY OF Brachiaria SEEDS AND DRY MASS YIELD ESTIMATE UNDER DIFFERENT IRRIGATED CROP-LIVESTOCK INTEGRATION SYSTEMS

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Carlos Alessandro Chioderoli

2010-08-01

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A velocidade e a amplitude da expansão de pastagens tropicais, no Brasil, estão associadas à disponibilidade de sementes de qualidade. Assim, objetivou-se avaliar, neste estudo, a qualidade fisiológica de sementes de duas espécies de braquiária, submetendo-as a testes de germinação e viabilidade, e, ainda, estimar, para ambas as espécies, a produtividade de massa verde e seca, em diferentes sistemas de integração lavoura-pecuária (ILP, sob irrigação. Na avaliação a campo, o arranjo experimental foi o de blocos completos casualizados, em parcelas subdivididas, alocando quatro consórcios nas parcelas (Brachiaria brizantha cv. Marandu e Brachiaria ruziziensis estabelecidas, simultaneamente, ao milho e por ocasião da adubação nitrogenada de cobertura e quatro épocas de corte da forragem, no inverno/primavera, nas subparcelas, com quatro repetições. Em laboratório, o delineamento foi inteiramente casualizado, com quatro repetições por tratamento/teste. Os testes de germinação e viabilidade indicaram que as sementes de B. brizantha apresentaram qualidade fisiológica superior às de B. ruziziensis, enquanto o teste de tetrazólio e as características das plântulas germinadas foram semelhantes. A B. ruziziensis, consorciada simultaneamente ao milho, foi o consórcio que se mostrou menos viável, em função da menor produtividade de massa verde, massa seca e deposição de resíduos vegetais na superfície do solo. No geral, a formação de pastagem para a entressafra, por intermédio do consórcio com o milho, se mostrou excelente alternativa na integração lavoura-pecuária, sob irrigação, em sistema plantio direto.

Avaliação de métodos para recuperação de pastagens de braquiária no agreste de Pernambuco: 1. aspectos quantitativos Evaluation of methods to recovery degraded pastures of Brachiaria in the agreste region of Pernambuco State: 1. quantitative aspects

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Maria da Conceição Silva; Mércia Virgínia Ferreira dos Santos; José Carlos Batista Dubeux Jr.; Mário de Andrade Lira; Daniel Fernando Ydoyaga Santana; Iderval Farias; Venézio Felipe dos Santos

2004-01-01

O experimento foi realizado com o objetivo de avaliar a resposta produtiva de uma pastagem degradada de Brachiaria humidicola (Rendle) Schweickt sob diferentes métodos de recuperação. O delineamento experimental foi blocos ao acaso com confundimento e em parcelas subdivididas, sendo a parcela principal representada pela combinação dos manejos com os níveis de adubação e as subparcelas pelos períodos de diferimento. Os tratamentos experimentais foram constituídos de quatro manejos de recuperaç...

Capim-braquiária sob lotação contínua e com altura única ou variável durante as estações do ano: dinâmica do perfilhamento Signalgrass under continuous stocking with fixed or variable height during the seasons: tillering dynamics

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Manoel Eduardo Rozalino Santos

2011-11-01

Full Text Available Objetivou-se estabelecer estratégias de manejo do pastejo, sob lotação contínua, que otimizem o padrão natural de perfilhamento da Brachiaria decumbens cv. Basilisk. Duas estratégias de manejo do pastejo foram estudadas: em uma, o pasto foi mantido com 25 cm de altura média durante todo o período experimental; e na outra foi mantido em 15 cm de altura média durante o inverno, com aumento para 25 cm a partir do início da primavera. Adotou-se o esquema de parcelas subdivididas em delineamento em blocos casualizados com quatro repetições. Consideraram-se como fator primário as estratégias de manejo do pastejo, caracterizadas pelas alturas médias em que os pastos foram mantidos durante as estações do ano (inverno, primavera e verão e, como fator secundário, as medidas ao longo do período experimental. A taxa de aparecimento de perfilho (4,7%, a taxa de mortalidade (4,7% e o índice de estabilidade (0,998 foram menores no inverno. Nesta estação, contudo, a taxa de sobrevivência de perfilho foi maior (95,3%. Em comparação aos pastos mantidos com 25 cm, aqueles manejados com 15 cm de altura média no inverno apresentaram maiores taxas de aparecimento de perfilho (34,2% e índice de estabilidade (1,065. O florescimento do capim-braquiária ocorreu apenas no verão e com pouca intensidade (0,5%. A otimização da renovação de perfilhos no pasto de B. decumbens cv. Basilisk sob lotação contínua ocorre com seu rebaixamento para 15 cm no início do inverno e seu posterior aumento para 25 cm no início da primavera.The experiment was conducted to establish management strategies of grazing under continuous stocking that optimize the natural pattern of tillering of Brachiaria decumbens cv. Basilisk. Two strategies of grazing management were studied: in one, the grass was maintained with 25-cm mean height throughout the experimental period, and in the other, 15-cm mean height during the winter, rising to 25 cm from beginning of

Ingestive Behavior of Heifers Supplemented with Glycerin in Substitution of Corn on Brachiaria brizantha Pasture.

Science.gov (United States)

Facuri, L M A M; Silva, R R; da Silva, F F; de Carvalho, G G P; Sampaio, C B; Mendes, F B L; Lisboa, M M; Barroso, D S; Carvalho, V M; Pereira, M M S

2014-11-01

The objective was to evaluate the ingestive behavior of crossbred heifers finished on a Brachiaria brizantha cv. Marandu pasture receiving four levels of glycerin in their supplementation. Thirty-six crossbred heifers with average initial weight of 264.83±3.83 kg and 20 months of age were distributed into a completely randomized design with four treatments and nine replications: control (0%), 4.82%, 10.12%, and 15.56% glycerin in the dry matter. The grazing time reduced linearly (p0.05). The number of rumination periods reduced linearly (p0.05) whereas the feed efficiency of neutral detergent fiber reduced linearly (p<0.05). Addition of glycerin in substitution of corn in supplements for animals managed on pastures does not influenced feed intake, but reduces the grazing time and increases the idle time. The supplementation also improves feed and rumination efficiencies.

Manejo da Planta Daninha Brachiaria plantaginea Resistente aos herbicidas Inibidores da ACCase Management of the Weed Brachiaria plantaginea Resistant to ACCase Inhibitor Herbicides

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P.J. Christoffoleti

2001-04-01

Full Text Available O objetivo deste trabalho foi estudar o manejo de uma população da planta daninha capim-marmelada (Brachiaria plantaginea resistente aos herbicidas inibidores da ACCase (ariloxifenoxipropionatos e ciclohexanodionas, utilizados na cultura da soja no sistema de plantio direto. Para isso, foram realizados dois experimentos: um utilizando herbicidas de manejo, com mecanismos de ação alternativos, comparando a eficácia destes com os inibidores da ACCase; e outro apenas com herbicidas inibidores da ACCase e aditivos misturados à calda. As sementes resistentes foram produzidas a partir de plantas comprovadamente resistentes; para comparação de resultados, foi utilizada uma população de capim-marmelada que nunca tinha sido pulverizada com inibidores da ACCase, portanto uma população suscetível. O experimento com os herbicidas de manejo foi realizado em condições de campo, porém as plantas ficaram em caixas com capacidade de 50 L, evitando-se a disseminação destas para áreas adjacentes. Concluiu-se que as plantas resistentes não apresentam resistência múltipla com herbicidas de manejo com mecanismos de ação alternativos, podendo os herbicidas glyphosate, paraquat, sulfosate, paraquat + diuron, MSMA e glufosinate ser utilizados no período entressafra das áreas com sistema de plantio direto, para manejo de populações resistentes de capim-marmelada aos herbicidas inibidores da ACCase. O experimento com aditivos foi realizado em casa de vegetação, com plantas em vasos individuais, utilizando sementes das populações suscetíveis e resistentes. Os herbicidas utilizados foram inibidores da ACCase, em cuja calda foram adicionados aditivos nitrogenados, do tipo uréia e sulfato de amônio, além de um tratamento sem aditivos. Concluiu-se que os aditivos não alteraram a eficácia dos herbicidas inibidores da ACCase nas plantas provenientes tanto da população suscetível quanto da resistente.The objective of this research was to

Photosynthetic light response of the C4 grasses Brachiaria brizantha and B. humidicola under shade

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Dias-Filho Moacyr Bernardino

2002-01-01

Full Text Available Forage grasses in tropical pastures can be subjected to considerable diurnal and seasonal reductions in available light. To evaluate the physiological behavior of the tropical forage grasses Brachiaria brizantha cv. Marandu and B. humidicola to low light, the photosynthetic light response and chlorophyll contents of these species were compared for plants grown outdoors, on natural soil, in pots, in full sunlight and those shaded to 30 % of full sunlight, over a 30-day period. Both species showed the ability to adjust their photosynthetic behavior in response to shade. Photosynthetic capacity and light compensation point were lower for shade plants of both species, while apparent quantum yield was unaffected by the light regime. Dark respiration and chlorophyll a:b ratio were significantly reduced by shading only in B. humidicola. B. humidicola could be relatively more adapted to succeed, at least temporarily, in light-limited environments.

Implementation of the Sulfur Hexafluoride Technique in Costa Rica to Quantify Enteric Methane in Cattle

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Johnny Montenegro Ballestero

2016-12-01

Full Text Available In order to implement, for the first time in Costa Rica, the sulfur hexafluoride (SF6 tracer technique to determine the enteric methane (CH4released by cattle consuming tropical forages, this study was carried out at the Universidad Tecnica Nacional, Atenas, from May to July 2013. This technique allows capturing and storing a sample of methane in a device placed over the animal. The implementation was done in two phases: confinement and grazing. In both phases, Jersey heifers were used. They were subjected to an adaptation phase prior to the collection of gas samples. Confinement diet consisted of transvala silopaca (Digitaria decumbens and Brachiaria brizantha. In the second phase B. decumbens was grazed. The three species had 35 days of regrowth without fertilization. The daily emission of methane per heifer in confinement was 147±7 g, and 17.3±1.1 g kg-1 DM consumed. During the grazing phase, heifers released 141±16 g of CH4 d-1, and 16.1±1.1 g of CH4 kg-1 DM of consumed grass was estimated. The emission factor (Ym: 4.9 ± 0.3% for the grazing phase was lower than that suggested by IPCC. It is concluded that this technique is suitable for use under similar conditions to those used in this research, and with the calculation of Ym it is possible to estimate with low uncertainty, the emission of enteric methane in cattle that should be used in the National Inventories Greenhouse Gases for the livestock sector in Costa Rica.

Biomass production and heavy metal absorption by four plants grown at the Moravia dump, Medellin, Colombia

International Nuclear Information System (INIS)

Solange Sanchez, Maria; Torrenegra, Ruben Dario; Martinez, Hernan; Salazar, Claudia Eugenia; Barahona, Rolando

2010-01-01

Dumps are sites where the presence of high heavy metal (HM) concentration is a common occurrence, creating the need for implementing restoration processes immediately after their closure. In the 7.6 ha and 45 m high Morro de Moravia dump, arose from the disposal of Medellin solid wastes from 1974 to 1984, previous studies have demonstrated high contents of contaminants, including HM, prompting the need to identify effective mechanisms to implement its restoration. The objective of this study was to evaluate the adaptation, growth and phytoremediation capacity of Bidens pilosa, Lepidium virginicum, Brachiaria decumbens and Arachis pintoi. Content of HM (mg/kg) in Moravia residue matrix went from 17 to 8193 for Pb, 44 to 564 for Cr, 0.2 to 339 for Cd and 77 to 1679 for Ni. Measurements of plant cover, plant height and dry matter production at all plant species studied suggested adequate growth and adaptation to the Moravia dump conditions. Plant absorption of HM showed the pattern Cr > Cd > Ni > Pb. Estimated bioconcentration factors were generally low, and maximum values were 0.36 in A. pintoi (Cr), 2.96 in B. pilosa (Cd) and 0.26 in B. decumbens (Ni). However, our estimations of the phytoremediation potential of the assayed species, suggested they possess low remediation efficiency. Further investigation should be carried out in order to identify more efficient HM accumulators, and to test the use of technologies such as modification of pH, rhizoremediation or the use of genetically enhanced accumulators to increase HM availability to plants

BIOMASS PRODUCTION AND HEAVY METAL ABSORPTION BY FOUR PLANTS GROWN AT THE MORAVIA DUMP, MEDELLIN, COLOMBIA

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Maria Solange Sanchez Pinzon

2010-05-01

Full Text Available Dumps are sites where the presence of high heavy metal (HM concentration is a common occurrence, creating the need for implementing restoration processes immediately after their closure. In the 7.6 ha and 45 m high Morro de Moravia dump, arose from the disposal of Medellín solid wastes from 1974 to 1984, previous studies have demonstrated high contents of contaminants, including HM, prompting the need to identify effective mechanisms to implement its restoration. The objective of this study was to evaluate the adaptation, growth and phytoremediation capacity of Bidens pilosa, Lepidium virginicum, Brachiaria decumbens and Arachis pintoi. Content of HM (mg/kg in Moravia residue matrix went from 17 to 8193 for Pb, 44 to 564 for Cr, 0.2 to 339 for Cd and 77 to 1679 for Ni. Measurements of plant cover, plant height and dry matter production at all plant species studied suggested adequate growth and adaptation to the Moravia dump conditions. Plant absorption of HM showed the pattern Cr > Cd > Ni > Pb. Estimated bioconcentration factors were generally low, and maximum values were 0.36 in A. pintoi (Cr, 2.96 in B. pilosa (Cd and 0.26 in B. decumbens (Ni. However, our estimations of the phytoremediation potential of the assayed species, suggested they possess low remediation efficiency. Further investigation should be carried out in order to identify more efficient HM accumulators, and to test the use of technologies such as modification of pH, rhizoremediation or the use of genetically enhanced accumulators to increase HM availability to plants

Influência da cobertura vegetal do solo na qualidade dos frutos de videira 'Niagara Rosada' Influence of soil cover with grass and leguminous plants on fruit characteristics of table grape variety Niagara Rosada

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Elaine Bahia Wutke

2005-12-01

Full Text Available Devido ao aumento no custo de produção com a utilização de cobertura morta com capim nas ruas da videira 'Niagara Rosada' e à dificuldade para sua aquisição, objetivou-se a possibilidade de substituí-la por plantas de cobertura intercalares. Em experimentos realizados em Indaiatuba e Jundiaí-SP, de 1999-2000 a 2003-2004, instalaram-se seis tratamentos nas entrelinhas, em blocos ao acaso e quatro repetições, constando de área no limpo; vegetação espontânea roçada; cobertura com capim seco de Brachiaria decumbens; cobertura verde de aveia preta (Avena strigosa; cobertura verde de chícharo (Lathyrus sativus; cobertura verde de tremoço (Lupinus albus, de março a outubro, seguidas de cobertura verde de mucuna anã (Mucuna deeringiana de outubro a março. Determinaram-se massa, comprimento e largura do cacho, engaço e bagas, número total de bagas por cacho e diâmetro do pedicelo de bagas, comparando-se os valores médios pelo teste de Duncan ao nível de 5%. Na média dos anos, os resultados com a cobertura verde foram similares ou mais favoráveis que os da cobertura com braquiária seca, podendo-se substituí-la por coberturas vegetais intercalares com gramínea e leguminosas, o ano todo, sem interferência negativa na qualidade comercial dos frutos.Grape vineyard in Southern Brazil utilize a large amount of mulch during autumn-winter season demanding extra efforts and costs, being its acquisition very difficult nowadays. In order to evaluate the possibility of replacing the tradicionally mulch by green cover species in the inter-row strip, two experiments were carried out in Indaiatuba and Jundiaí, SP, Brazil, from 1999/00 to 2003/04, with the table variety Niagara Rosada. The experimental design was a randomized block with four replications and six treatments: 1 no weeded area; 2 cut spontaneous local vegetation; 3 mulch of Brachiaria decumbens; 4 green cover of Avena strigosa from March to October followed by green cover of

ACUMULAÇÃO DE NUTRIENTES EM FOLHAS DE MILHETO E DOS CAPINS BRAQUIÁRIA E MOMBAÇA NUTRIENT ACCUMULATION IN LEAVES OF MILLET, BRACHIARIA AND GUINEAGRASS

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Antônio Joaquim Braga Pereira Braz

2007-09-01

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O milheto (Pennisetum glaucum e os capins braquiária (Brachiaria brizantha cv. Marandu e mombaça (Panicum maximum cv. Mombaça são importantes gramíneas cultivadas nos solos sob cerrados, da região Centro-Oeste do Brasil, utilizadas principalmente para pastoreio. O objetivo deste trabalho foi avaliar a acumulação dos nutrientes N, P, K, Ca, Mg, Zn, Cu, Mn e Fe nas folhas dessas gramíneas, em função dos dias após a emergência da planta. O experimento foi conduzido em Latossolo Vermelho distrófico, na Embrapa Arroz e Feijão, em Santo Antônio de Goiás, GO. Os tratamentos foram testados em blocos ao acaso, com quatro repetições, em parcelas de 6,0 m de largura e 20 m de comprimento. No plantio foram usados 400 kg/ha de adubo da fórmula comercial 5-30-15. O plantio foi feito em dezembro de 2001 e, durante o ciclo das culturas, foram feitas nove amostragens de folhas para análise química, em diferentes períodos, tomados em dias após emergência. De posse da massa seca e da concentração dos nutrientes calcularam-se as respectivas acumulações no limbo foliar das três gramíneas. Fez-se o ajuste dos dados de acumulação do nutriente (Y, em função de dias após a emergência, por um modelo exponencial quadrático: Y= a exp(bx + cx2. O milheto foi a gramínea que mais acumulou nutrientes no limbo foliar e em menor tempo, seguido pelos capins mombaça e braquiária. Entre os macronutrientes, as maiores acumulações foram as de N e as de K, e as menores, as de P. Entre os micronutrientes, o ferro foi o elemento que apresentou maior acúmulo no limbo foliar das três gramíneas.

PALAVRAS-CHAVE: Gramíneas; nutrição mineral; Brachiaria brizantha; Pennisetum glaucum; Panicum maximum.

Millet (

Intoxicações por plantas em ruminantes e equídeos no Sertão Paraibano Plant poisonings in ruminants and equidae in the Sertão of Paraiba, Brazil

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Tales S. Assis

2009-11-01

Full Text Available Foi realizado um levantamento das intoxicações por plantas em 20 municípios do Sertão Paraibano, onde foram entrevistados 50 produtores e 11 médicos veterinários. De acordo com o levantamento realizado, Ipomoea asarifolia e Mascagnia rigida são as intoxicações mais importantes. Indigofera suffruticosa, as plantas cianogênicas (Sorghum vulgare, Piptadenia macrocarpa e Manihot spp., Mimosa tenuiflora, Aspidosperma pyrifolium e Crotalaria retusa são plantas importantes como causa de intoxicações na região. Os entrevistados relataram casos esporádicos de intoxicação por Ricinus communis, Enterolobium contortisiliquum, Prosopis juliflorae Brachiaria decumbens. Ziziphus joazeiro, Passiflora sp., Caesalpina ferrea e Crescentia cujete foram mencionadas como causa de abortos em ruminantes. Frutos de Crescentia cujete foram administrados a duas cabras prenhes causando mortalidade perinatal e abortos. As cascas de feijão (Phaseolus vulgaris e Vigna unguiculata e as folhas de Licania rigida (oiticica são associadas à sobrecarga ruminal em bovinos. As frutas de Mangifera indica (mangae Anacardium occidentale (cajú são responsabilizadas por causarem intoxicação etílica. Dalechampia sp. e Croton sp. foram citadas pelos entrevistados como possíveis plantas tóxicas, que ainda não tiveram sua toxicidade comprovada.A survey of plant poisoning in ruminants and equidae was conducted in 20 municipalities of the semiarid region of the Sertão Paraibano. Fifty farmers and 11 veterinary practitioners were interviewed. Ipomoea asarifolia and Mascagnia rigida are the most important poisonous plants in the region. Indigofera suffruticosa, the cianogenic plants (Sorghum vulgare, Piptadenia macrocarpa, and Manihot spp., Mimosa tenuiflora, Aspidosperma pyrifolium and Crotalaria retusa cause also important intoxications in the area. Sporadic outbreaks of poisonings by Ricinus communis, Enterolobium contortisiliquum, Prosopis juliflora and Brachiaria

Efeito do cultivo da soja na dinâmica da população bacteriana, em solos de cerrado Effects of soybean cultivation on the bacterial population dynamics in cerrado soils

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JOÃO CARLOS PEREIRA

2000-06-01

Full Text Available Este trabalho teve por objetivo avaliar a influência do cultivo da soja sobre a dinâmica da população bacteriana, em dois solos de Cerrado do Estado de São Paulo, originalmente cobertos com Paspalum notatum (em Barretos e Brachiaria decumbens (em S��o Carlos. Nesses solos, a densidade da população de bactérias em geral variou de 398,1 x 10³ a 467,7 x 10³ e de 123 x 10³ a 218,8 x 10³ ufc (unidades formadoras de colônias/g de solo seco, respectivamente. O cultivo da soja, em ambos os solos, resultou em incrementos variados nos números de ufc/g de solo seco da população de bactérias em geral, das resistentes aos antibióticos estreptomicina e cloranfenicol, e de actinomicetos. A população de actinomicetos ocorreu no solo principalmente como esporos, e as variações das relações esporos/hifas entre os solos não-rizosférico e rizosférico não foram significativas. Os resultados evidenciam que o cultivo da soja influenciou de forma diferenciada a população desses solos.The effect of soybean cultivation on the population dynamics of the bacterial community was evaluated in two "Cerrado" soils of São Paulo State, Brazil. The experimental areas, in the vicinities of the cities of São Carlos and Barretos, were previously cultivated, respectively, with Paspalum notatum and Brachiaria decumbens. The bacterial population densities in these soils varied from 398.1 x 10³ to 467.7 x 10³ cfu (colony forming units and from 123 x 10³ to 218.8 x 10³ cfu/g of dried soil, respectively, in São Carlos and Barretos soils. Soybean cultivation in both soils resulted in increments in the total bacterial population density, in the actinomycetes population, and in the bacterial population resistant to the antibiotics streptomycin and chloramphenicol. Actinomycetes were present in these soils mainly as spores. Soybean cultivation did not alter the actinomycetes spores/hyphae ratio when comparing rhizospheric and non-rhizospheric soils

Crescimento inicial de espécies florestais na recomposição da mata ciliar em taludes submetidos à técnica da bioengenharia de solos.

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Francisco Sandro Rodrigues Holanda

2010-08-01

Full Text Available A Bacia Hidrográfica do rio São Francisco, vem sendo submetida a fortes impactos ambientais por meio de alterações do regime hidrológico e sedimentológico, além de avançada destruição da sua mata ciliar. A vegetação ciliar possui importante função na proteção das margens dos rios promovida pela cobertura vegetal e seu sistema radicular, melhorando a agregação de um solo pouco coeso, diminuindo o arraste de partículas e, consequentemente resultando em menor taxa de erosão e assoreamento do curso d'água. Este trabalho teve como objetivo avaliar o crescimento inicial de espécies florestais em talude marginal submetido à técnica de bioengenharia de solos no rio São Francisco. A bioengenharia de solos foi composta pela cobertura longitudinal do talude com o biotêxtil (Tela Fibrax® 400BF, e em razão das variações diárias de cota do rio foram também utilizados retentores de sedimentos (Bemalonga® D40 para redução ao impacto da água na base do talude, evitando o solapamento promovido pelo fluxo e refluxo das ondas. Antes da fixação do biotêxtil, foram semeadas a lanço sementes da espécie Brachiaria decumbens para promoção de uma rápida cobertura vegetal. Em seguida foram plantadas mudas de seis espécies florestais nativas da região: aroeira vermelha (Schinus terebinthifolius Raddi., pau-pombo (Tapirira guianensis Aubl., mulungu (Erythrina velutina Willd., tamboril (Enterolobium contortisiliquum (Vellozo Morong, canafístula (Cassia grandis L.f. e pau-ferro (Caesalpinia leiostachya (Bentham Ducke. O desenvolvimento das mudas foi analisado por meio da Taxa de Crescimento Relativo de Altura da parte aérea e Diâmetro do colo. Após 360 dias, ao final das avaliações, observou-se que o maior número de indivíduos vivos foi identificado no tratamento com bioengenharia de solos. A grande densidade e agressivo crescimento da espécie Brachiaria decumbens na área com biotêxtil, trouxe danos para o

Avaliação de fontes de amônia para o tratamento de fenos de gramíneas tropicais. 1. Constituintes da parede celular, poder tampão e atividade ureática Evaluation of ammonia sources to tropical grasses hays treatment. 1. Cell wall contents, buffer capacity and urease activity

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Ricardo Andrade Reis

2001-06-01

Full Text Available Avaliaram-se as alterações da fração fibrosa e as características químicas dos fenos de braquiária decumbens (Brachiaria decumbnes Stapf e jaraguá (Hyparrhenia rufa Ness Stapf não-tratados, tratados com uréia (U-5,4% da MS, uréia (UL-5,4% da MS mais labe-labe (Lablab purpureus L. Sweet, cv. Highworth-3,0% da MS ou amônia anidra (NH3 -3,0% da MS. O tratamento químico com uréia ou NH3 aumentou o pH e a digestibilidade in vitro verdadeira dos fenos. A amonização não alterou os teores de fibra em detergente ácido e celulose, mas diminuiu os de fibra em detergente neutro, hemicelulose e lignina. O uso do labe-labe como fonte adicional de urease não aumentou a eficiência da uréia no tratamento dos volumosos. As avaliações do conteúdo de umidade, do poder tampão e da atividade ureática são técnicas que podem auxiliar na previsão das respostas dos volumosos à amonização com o uso de uréia.The experiment was conducted to evaluate the changes on the chemical composition and the in vitro dry matter digestibility (IVDMD of the Brachiaria decumbens Stapf, jaraguá (Hyparrhenia rufa Ness Stapf hays, untreated, treated with urea (5.4% DM, urea (UL-5.4% DM and lab lab (Lablab purpureus L. Sweet, cv. Highworth-3.0% DM; and anhydrous ammonia (NH3 3.0% DM. The chemical treatment increased the pH and the in vitro digestibility of the hays Ammoniation did not affect ADF and cellulose contents. The NDF, hemicellulose and lignin contents decreased due to ammoniation with NH3. The urea utilization had the same efficiency that anhydrous ammonia on the hemicellulose content of the hays. The use of an external source of urease did not affect the urea treatment efficiency. The evaluation of the chemical characteristics of the forages, as the dry matter content, buffering capacity, and urease activity can be helpful on the prediction of their responses to the ammoniation.

Avaliação da produção de bezerros em confinamento ou em suplementação exclusiva Evaluation of production of calves in feed lot or in creep feeding systems

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L.C.V. Ítavo

2007-08-01

Full Text Available Avaliou-se o desempenho de vacas e bezerros desmamados aos 90 (D90 e aos 210 (D210 dias, utilizando-se 36 vacas Beefalo-Nelore, multíparas e seus bezerros, em delineamento experimental de blocos ao acaso, com 18 repetições, sendo nove machos e nove fêmeas. Aos 90 dias pós-parto os bezerros foram pesados e distribuídos em dois tratamentos, adotando-se para a formação do bloco o peso e o sexo do bezerro. Os dois tratamentos foram creep-feeding (D210 e confinamento (D90. Os bezerros (D210 foram criados em pastagem de Brachiaria decumbens e B. humidicula com 48 hectares Os bezerros (D90 foram confinados em 7,95m²/animal e receberam capim elefante picado e concentrado. As médias de consumo de matéria seca do concentrado, do peso ao desmame e do ganho de peso foram 0,56 e 1,69kg/dia; 208,68 e 185,67kg; 0,75 e 0,52kg/dia, respectivamente, para bezerros D210 e D90. Matrizes D90 apresentaram maior peso (448,86kg aos 210 dias pós-parto. Sugere-se a suplementação excluviva, ou creep-feeding, para desmame de bezerros mais pesados.Performances of cows and calves weaned at 90 (D90 and 210 days of age (D210 were evaluated, using 36 Beefalo-Nelore multiparus cows and their calves, in a randomized block experimental design, with 18 replicates of nine animals of each sex. Calves were allotted to treatments using as criteria to form blocks, the weight and sex of the animal. Calves (D210 were raised in 48ha pasture of Brachiaria decumbens e B. humidicula. Calves (D90 were raised in feedlot condition, in an area of 7.95m² /animal, and were fed chopped elephant grass and concentrate. The average concentrate dry matter intake, weaned body weight and weight gain were, respectively, 0.56 and 1.69kg/day; 208.68 and 185.67kg; 0.75 and 0.52kg/day respectively for D210 e D90 calves. Cows from D90 treatment showed higher body weight (448.86kg at 210 days post partum. Creep-feeding is suggested for weaning heavier calves.

Evaluation of new hybrid brachiaria lines in Thailand. 1. Forage production and quality

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Michael D. Hare

2015-05-01

Full Text Available Forty-three new hybrid bracharia lines were evaluated for forage accumulation and nutritive value in Northeast Thailand from 2006 to 2011 in experiments at 2 sites, using Mulato II hybrid brachiaria as a standard for comparison. The parameters evaluated were wet and dry season dry matter (DM accumulation, leaf:stem ratio, crude protein (CP concentration and fiber level [acid detergent fiber (ADF and neutral detergent fiber (NDF]. No lines consistently displayed superior dry season forage accumulation and leaf:stem ratio over Mulato II. In the wet seasons, 14 lines produced more DM than Mulato II but in only one wet season each. Mulato II produced forage with high leaf:stem ratio in all seasons. Many lines did have significantly higher CP concentrations and lower levels of ADF and NDF than Mulato II, but their forage accumulation and leaf:stem ratio were inferior. Four lines (BR02/1718, BR02/1752, BR02/1794 and BR02/0465 were granted Plant Variety Rights in 2011.Keywords: Cayman, Cobra, crude protein, dry matter yields, forage regrowth,  Mulato II.DOI: 10.17138/TGFT(383-93 

Características químicas de solo submetido ao tratamento com esterco líquido de suínos e cultivado com gramíneas forrageiras

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Queiroz Flávia Martins de

2004-01-01

Full Text Available Avaliou-se, neste trabalho, o efeito da aplicação intensiva de esterco líquido de suínos (ELS, pelo método do escoamento superficial, nas características químicas de um solo Podzólico Vermelho-Amarelo cultivado com quatro espécies forrageiras: quicuio da Amazônia (Brachiaria humidicola (Rendle Schweick, braquiária (Brachiaria decumbens Stapf, coastcross (Cynodon dactylon (L. Pers. e tifton 85 (Cynodon spp.. O ELS foi aplicado em parcelas de 4m² e com 5% de declividade, durante 4 meses, na taxa média equivalente a 800kg ha-1d-1 de demanda bioquímica de oxigênio (DBO5. Para caracterização química, amostras de solo foram coletadas à profundidade de 0-0,20m, antes de iniciar o experimento e após o término dele. A aplicação de ELS proporcionou acúmulo de P, K, Na e Zn no solo, enquanto as concentrações de Mg e Cu diminuíram e a de Ca se manteve inalterada. Houve aumento na acidez, na soma de bases, na CTC e redução na saturação por bases. Devido ao acúmulo de nutrientes, recomenda-se monitoramento das características químicas do solo, ao longo de seu perfil e das águas subterrâneas para que se avaliem riscos de contaminação ambiental.

Densidade e diversidade fenotípica de bactérias diazotróficas endofíticas em solos de mineração de bauxita, em reabilitação Density and phenotypic diversity of endophytic nitrogen fixing bacteria in soils under rehabilitation after bauxite mining

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R. Melloni

2004-02-01

diversidade fenotípica no ambiente estudado.Diazotrophic endophytic bacteria enhance plant growth through biological nitrogen fixation and production and release of plant growth regulating substances, which facilitate the revegetation of areas degraded by human activities. However, little is known about populations of such bacteria in soils or plants of mining areas. Aiming to study the effects of different vegetation types and rehabilitation periods on some endophytic diazotrophic bacteria species, soil samples were collected under two environmental conditions ("Campo" and "Serra" in bauxite mined areas undergoing different rehabilitation processes. Population densities were evaluated by the most probable number method in media (NFb, JNFb, and Fam for Azospirillum brasilense and A. lipoferum, Herbaspirillum spp. and A. amazonense, respectively and ranged from 0 to 2.0 x 10(4 bacteria g-1 soil. The vegetation types affected the diazotrophic populations. Highest densities were found in mined soils revegetated with the grass species brachiaria (Brachiaria decumbens, rye grass (Lolium multiflorum and capim-gordura (Melinis minutiflora. However, these densities are considered low compared to those found in agricultural soils. No relationship was found between the rehabilitation time and population density. Thirty-six cultural phenotypes were found on potato medium among 72 isolates out of all three culture media. At a similarity of at least 63 %, these isolates formed seven great groups, five of which (comprising 62.5 % of the total isolates contained the type strains of Burkholderia brasilensis, Herbaspirillum seropedicae, and Azospirillum spp. (A. brasilense, A. amazonense, A. lipoferum, A. irakense. In spite of its low density, this group of bacteria presented a high phenotypic diversity in the studied environment.

Consumo e digestibilidade aparente total dos nutrientes e ganho de peso de bovinos de corte alimentados com silagem de Brachiaria brizantha e concentrado em diferentes proporções Intake and apparent digestibility of the nutrients and weight gain of beef cattle fed diets with different proportions of Brachiaria brizantha silage and concentrate

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Bruno Ceolin da Silva

2005-06-01

Full Text Available Avaliaram-se o consumo e as digestibilidades aparentes totais dos nutrientes e o ganho de peso de bovinos de corte recebendo dietas contendo concentrado e silagem de Brachiaria brizantha cv. Marandu nas seguintes proporções: 20:80, 35:65, 50:50 e 65:35, com base na matéria seca. Foram utilizados vinte e quatro animais castrados Holandês x Zebu, com peso vivo inicial médio de 364 kg, distribuídos em um delineamento em blocos casualizados. Por ocasião da ensilagem, procedeu-se o tratamento do capim com o inoculante enzimo-bacteriano Nutroeste 50 t. Para o cálculo da matéria seca fecal, utilizou-se a fibra em detergente ácido indigestível (FDAI como indicador. Os animais foram alojados em baias individuais e alimentados ad libitum. O ensaio teve duração de 84 dias, divididos em três períodos de 28 dias após 15 dias de adaptação. Os consumos médios de matéria seca (MS, matéria orgânica (MO, proteína bruta (PB, extrato etéreo (EE e carboidratos totais (CHO e as digestibilidades aparentes totais de MS, MO, CHO e carboidratos não-fibrosos (CNF elevaram linearmente com o aumento dos níveis de concentrado nas dietas. Comportamento semelhante foi observado para o ganho de peso médio diário, estimando-se incrementos de 0,0184 kg/unidade de concentrado adicionado. Contudo, as digestibilidades aparentes de PB, EE e fibra em detergente neutro (FDN não foram influenciadas pelas dietas, registrando-se, respectivamente, valores médios de 77, 88 e 60%. Silagem de Brachiaria brizantha não-emurchecida, constituindo 50% da dieta de bovinos H x Z, promoveu ganhos de peso em torno de 1,0 kg/dia.Intake and total apparent digestibilities of the nutrients and average daily gains (ADG by beef cattle fed diets based on concentrate and Brachiaria brizantha cv. Marandu silage in the following proportions: 20:80, 35:65, 50:50 and 65:35, in dry matter basis were evaluated. Twenty-four crossbred (Holstein x Zebu steers, with initial live weight of

DESEMPENHOS TÉCNICOS E ECONÔMICOS DA CONSORCIAÇÃO DE MILHO COM FORRAGEIRAS DOS GÊNEROS Panicum E Brachiaria EM SISTEMA DE INTEGRAÇÃO LAVOURA-PECUÁRIA TECHNICAL AND ECONOMIC PERFORMANCE OF CORN INTERCROPPED WITH Panicum AND Brachiaria FORAGE IN CROP-LIVESTOCK INTEGRATION SYSTEM

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Carlos Alessandro Chioderoli

2009-10-01

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O trabalho teve como objetivo analisar a produtividade de grãos e os resultados econômicos de modalidades do cultivo de milho com forrageiras dos gêneros Panicum e Brachiaria, na integração lavoura-pecuária (ILP, sob sistema plantio direto (SPD. O experimento foi conduzido no ano agrícola de 2007/2008, no município de Selvíria, MS, em Latossolo Vermelho distroférrico. O delineamento experimental utilizado foi o de blocos casualizados, com quatro repetições, sendo os tratamentos constituídos por oito modalidades de cultivo do milho consorciado, simultaneamente e por ocasião da adubação nitrogenada de cobertura com os capins Tanzânia, Mombaça, Marandu e Ruziziensis, além do seu cultivo sem consórcio. A análise dos custos operacionais foi baseada nos preços de insumos e operações e a receita bruta no preço médio de venda do milho, no Estado de São Paulo. O decréscimo dos valores da relação custo/benefício e os melhores retornos econômicos, obtidos em função dos maiores índices de margem de contribuição, determinaram as modalidades de cultivo mais viáveis. Os capins Mombaça e Marandu, consorciados, simultaneamente, ao milho, reduziram a produtividade de grãos, em relação ao milho cultivado sem o consórcio. Com relação aos benefícios técnico-econômicos, visando à utilização em sistemas de ILP, o consórcio mais recomendado é o de milho com capim Tânzania, principalmente no cultivo simultâneo. No entanto, resultados técnico-econômicos a longo prazo, com diferentes preços e produtividades, devem ser avaliados

Cytogenetic evidence for genome elimination during microsporogenesis in interspecific hybrid between Brachiaria ruziziensis and B. brizantha (Poaceae

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Andréa Beatriz Mendes-Bonato

2006-01-01

Full Text Available Microsporogenesis was analyzed in an interspecific hybrid between an artificially tetraploidized sexual accession of Brachiaria ruziziensis (R genome and a natural apomictic tetraploid accession of B. brizantha (B genome. Chromosomes associated predominantly as bivalents. From this phase to the end of meiosis, chromosomes presented irregular segregation and abnormal arrangement in the metaphase plate. During metaphase I, in 27.8% of meiocytes, bivalents were distributed in two metaphase plates. In anaphase I, two distinct and typical bipolar spindles were formed. In 29.7% of pollen mother cells, one genome did not divide synchronically, with chromosomes lagging behind or not segregating at all. The second division was very irregular, resulting in polyads. Based on previous results from analysis of a triploid hybrid between these species, where the R genome was eliminated by asynchrony during meiosis, it is suggested that the laggard genome in this hybrid also belongs to B. ruziziensis.

Influência de esterco bovino e calcário sobre o efeito residual da adubação fosfatada para a Brachiaria brizantha cultivada após o feijoeiro Influence of cattle manure and limestone on residual effects of phosphorus fertilizer in Brachiaria brizantha grown after common bean

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Renato Ferreira de Souza

2010-02-01

to evaluate the influence of manure and lime applications on the residual effect of phosphorus applied to common bean on phosphorus nutrition and yield of Brachiaria brizantha grown in succession. Four experiments were conducted in a greenhouse, in a completely randomized design, in a 4 x 5 factorial layout with three replications. Each experimental unit consisted of a pot containing 4 dm³ of the following soil: clayey dystrophic Red Latosol (Oxisol, sandy clay loam dystrophic Red-Yellow Latosol (Oxisol, sandy loam dystrophic Red-Yellow Latosol (Oxisol, or sandy orthic Quartzarenic Neosol (Quartzpsament. Each soil represented an experiment and was treated with four liming levels (0.0; 0.5; 1.0 and 2.0 times the recommended dose to reach 60 % base saturation and five doses of cattle manure (0.0; 2.5; 5.0; 7.5 and 10.0 % of the soil volume. In each pot, bean plants were grown and harvested and followed by planting of three brachiaria plants, which were cut 70, 160 and 290 days after seedling emergency. Total dry matter productions and P accumulation in the above-ground part of the brachiaria plants were positively influenced by manuring and liming. These treatments influenced positively the residual effect of P fertilizer applied to the bean plants, in terms of P nutrition and production of the succession Brachiaria brizantha crop.

The seasonal variations of allelopathic activity and allelopathic substances in Brachiaria brizantha.

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Kobayashi, Ai; Kato-Noguchi, Hisashi

2015-12-01

Controlling weeds through allelopathy is one strategy to reduce dependency on synthetic herbicides. The plant shoots of the grass Brachiaria brizantha incorporated into the field soil were found to inhibit the growth of several plant species. We investigated the variations of allelopathic activity and allelopathic substances in B. brizantha harvested in June, October and January. All extracts of B. brizantha obtained from June, October and January inhibited the root and shoot growth of cress, lettuce, Phleum pretense and Lolium multiflorum in a concentration dependent manner. However, the inhibitory activity of B. brizantha of June and October was greater than that of B. brizantha of January. Concentrations of three potent allelopathic active substances, (6R,9S)-3-oxo-α-ionol, (6R,9R)-3-oxo-α-ionol and 4-ketopinoresinol were also greater in B. brizantha of June and October than those in B. brizantha of January. The results suggest that the allelopathic activity and the levels of those allelopathic active substances are greater in B. brizantha of June and October than those in B. brizantha of January. It is possible that B. brizantha could be useful for a weed suppressive residue or soil additive materials in the variety of agricultural settings to develop sustainable agriculture options. The effectiveness of B. brizantha of June and October as a weed suppressive agent may be greater than that of January.

Análise conjunta de atributos físicos e biológicos do solo sob sistema de integração lavoura-pecuária

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Rogério Ferreira da Silva

2011-10-01

Full Text Available O objetivo deste trabalho foi avaliar os efeitos do sistema integração lavoura-pecuária (ILP sobre os atributos morfológicos, físicos e biológicos do solo. O experimento foi realizado em Dourados, MS, em Latossolo Vermelho distroférrico típico. Foram avaliados os seguintes sistemas: monocultura com sistema convencional de preparo do solo, ILP com sistema plantio direto, pastagem contínua de Urochloa decumbens (Syn. Brachiaria decumbens e vegetação nativa. Em cada sistema, foi aberta uma trincheira com o intuito de detectar as modificações morfológicas provocadas pelos diferentes manejos com uso do método do perfil cultural. Os macroinvertebrados do solo foram avaliados conforme o método "Tropical Soil Biology and Fertility". Utilizaram-se, ainda, amostras de solo indeformadas para avaliação dos atributos físicos do solo (densidade do solo, porosidade total, macro e microporosidade. Entre os sistemas produtivos, a melhor estrutura do solo foi verificada no sistema ILP, nas camadas de 0-0,1 e 0,1-0,2 m. Os sistemas sob ILP e em pastagem cultivada continuamente favoreceram um ambiente edáfico biologicamente mais ativo em comparação aos outros sistemas cultivados. A visualização conjunta dos atributos do solo mostrou que a integração lavoura-pecuária é uma estratégia para desenvolver sistemas de produção sustentáveis e que o período de dois anos de manejo é adequado para a rotação lavoura-pecuária.

Soil chemical atributtes on brachiaria spp in integrated crop livestock system

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Valdinei Tadeu Paulino

2013-12-01

Full Text Available Integrated crop-livestock systems have attracted more interest in the last few years due to their capacity of improving stability and sustainability of agricultural systems when compared to more specialized production ones. The crop-livestock integration is an effective technique, but complex to maintain pasture productivity and its recovery, whose efficiency depends on soil physical management and its chemical fertility. Regarding the soil fertility, the corrective practices generally begin with the liming due to the high acidity of most Brazilian soils and low levels of Ca and Mg in the exchange complex and high Al saturation. In areas of crop-livestock systems, liming corrects the surface acidity potential. However, this practice can leave the subsoil with excess aluminum and lack of calcium, which inhibit root growth and affect the absorption of water and nutrients. The application of gypsum allows the improvement of the subsoil, reducing Al saturation and increasing levels of calcium and sulfur. The aim of this study was to investigate changes in the soil chemical properties of a Haplorthox soil in integrated crop-livestock system (ICL with Brachiaria brizantha cv. Marandu and Piatã, Brachiaria ruziziensis with gypsum and liming application. This study was conducted at the Instituto de Zootecnia, Nova Odessa/SP, a pasture established on a soil with medium texture (61.4% sand, silt 14.6% and 24.0% clay. The treatment plots consisted on integration crop-livestock (ICL cultivated - maize and B. Marandu,  ICL - maize and B. ruziziensis, ICL - maize and B. Piatã and an untreated control group (control - without liming and fertilization grazed pasture throughout the year, located immediately adjacent to the ICL evaluation, which was cultivated for 25 years with B. brizantha cv. Marandu. All pastures were desiccated in October with glyphosate-based herbicide (4 liters per hectare. Then gypsum (1.2 Mg ha-1 and liming (1.2 Mg ha-1 were applied

Competitivity of the common-bean plant relative to the weed alexandergrass [Brachiaria plantaginea (link hitch.] Competitividade do feijoeiro-comum com o capim-marmelada [Brachiaria plantaginea (link hitch.

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Telma Passini

2003-01-01

Full Text Available Methodologies of competitive interaction quantification between weeds and crops are not widely elucidated and compared in the literature. The competitive ability of common-bean (Phaseolus vulgaris relative to alexandergrass (Brachiaria plantaginea was assessed and two approaches of replacement series experiment analysis were compared. The response of the species to the presence of each other at different densities and proportion was evaluated. Replacement series at total densities of 625, 816 and 1,111 plants m-2 were performed at the proportions of common-bean:alexandergrass of 100:0 (pure stand of common-bean, 75:25, 50:50, 25:75 and 0:100% (pure stand of alexandergrass, at four replicates in a randomized block design. Data analyses were performed by the qualitative compared to the quantitative approach. The quantitative approach provided larger number of information than did the qualitative approach, and indicated that there was intraspecific competition among common-bean plants, and a minimum of interspecific competition from alexandergrass. There was no intraspecific competition among alexandergrass plants, being the crop effect on the weed larger than the effect among alexandergrass plants. The ecological niche differentiation was partial, since the crop intraspecific competition was larger than the interspecific, and the last one was negligible, at the same time that the weed interspecific competition was larger than the intraspecific. Common-bean, as a competitor species, is superior to alexandergrass.As metodologias de quantificação das interações competitivas entre plantas cultivadas e daninhas não estão amplamente elucidadas e comparadas na literatura. A competitividade da cultura de feijão-comum (Phaseolus vulgaris em relação ao capim-marmelada (Brachiaria plantaginea foi avaliada pela comparação entre o método qualitativo e um método quantitativo de análise de resultados. A resposta de cada espécie à presença da

Cattle production supplemented on signal grass pastures during the rainy season

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Manoel Eduardo Rozalino Santos

2016-01-01

Full Text Available The effects of four supplement doses (0, 1, 2 and 3 kg animal-1 day-1 on pasture characteristics and on cattle production on Brachiaria decumbens cv. Basilisk pastures in continuous stocking with variable stocking rate were assessed. Experimental design comprised completely randomized blocks with two replications. Concentrate supplementation did not influence mass (4141 kg ha-1 of DM and production rate of forage (97.6 kg ha-1 day-1 of DM, morphological components and nutrition value in hand-plucked forage. Similarly, the number of live (1.607 tillers m-² and dead (636 tillers m-² tillers was not affected by concentrate supplementation. There were linear increases in animal performance (from 0.70 to 1.13 kg animal-1 day-1, stocking rate (1.9 to 3.8 animal unit ha-1 and animal production per area (1.8 to 6.2 kg ha-1 body weight with supplementation doses. Concentrate supplementation does not change the structural characteristics of signal grass pastures managed in continuous stocking at 20 cm high, but increases animal production.

Redução da infestação de Brachiaria plantaginea em soja pela cobertura do solo com palha de aveia-preta Reduction of Brachiaria plantaginea infestation on soybean crop with black oat residues

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GIOVANI THEISEN

2000-04-01

Full Text Available Este trabalho foi conduzido em área da Universidade Federal do Rio Grande do Sul, em Eldorado do Sul, RS, em 1996/97, com o objetivo de avaliar os efeitos de resíduos de aveia-preta (Avena strigosa Schreb. sobre o solo na densidade de papuã (Brachiaria plantaginea (Link Hitch. e no rendimento da cultura da soja (Glycine max L. Merrill. O experimento foi conduzido em delineamento de blocos casualizados em parcelas subdivididas, com quatro repetições; os tratamentos método de controle de papuã (nas parcelas e cobertura do solo (nas subparcelas foram arranjados em esquema fatorial. A densidade da planta daninha diminuiu de forma exponencial com o aumento da cobertura de aveia sobre o solo, variando de 829 a 86 plantas/m² para níveis de cobertura 0,0 t/ha e 10,5 t/ha, respectivamente. Houve maior infestação de papuã nas linhas do que nas entrelinhas da cultura. Não houve efeito da cobertura vegetal no rendimento da soja quando a cultura foi mantida livre de papuã. Por sua vez, níveis crescentes de resíduos vegetais sobre o solo controlaram papuã e aumentaram linearmente o rendimento da cultura. Nas condições de alta infestação da área, a produção de grãos aumentou na razão de 158 kg/ha de grãos por tonelada de palha sobre o solo.This work was conducted at Universidade Federal do Rio Grande do Sul, in Eldorado do Sul, Rio Grande do Sul State, Brazil, during 1996/97, to evaluate the effect of black oats (Avena strigosa Schreb. residues on alexandergrass (Brachiaria plantaginea (Link Hitch. density and on soybean (Glycine max L. Merrill yield. Treatments were arranged in split-plot in a randomized complete block design with four replicates, with weed control method as main plots and level of black oat residues as subplots. An exponential reduction of alexandergrass density was observed, with data varying from 829 to 86 plants/m² for levels of straw on the soil surface of 0 to 10.5 ton/ha, respectively. Higher weed

Manejo químico de Eichhornia crassipes e Brachiaria subquadripara com Diquat em condições de reservatório Chemical control of Eichhornia crassipes and Brachiaria subquadripara with Diquat under reservoir conditions

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D. Martins

2011-03-01

Full Text Available Este trabalho teve como objetivo avaliar a eficiência do herbicida diquat no controle de plantas de Eichhornia crassipes e Brachiaria subquadripara em condições de reservatório. As parcelas experimentais apresentavam 650 m² e foram delimitadas e posicionadas por redes de pesca nas margens do reservatório de Salto Grande, Americana-SP. Os tratamentos testados foram: herbicida diquat aplicado na formulação Reward, nas doses de 960 g i.a. ha-1 (duas aplicações de 480 g, com intervalo de 15 dias, 960 g i.a. ha-1 (aplicação única, 1.920 g i.a. ha-1 (duas aplicações de 960 g, com intervalo de 15 dias, além de uma testemunha sem aplicação do herbicida. Para monitoramento das concentrações de diquat, foram coletadas amostras de água antes da aplicação do herbicida e 1, 2, 4, 7, 14 e 28 dias após aplicação (DAA na área experimental e na montante e jusante da barragem. A análise da eficiência do diquat foi realizada através de avaliações visuais de controle no período (1, 2, 4, 7, 14, 21 e 28 DAA do herbicida e aos dois dias após a segunda aplicação. O herbicida diquat mostrou-se eficiente no controle das plantas de E. crassipes, independentemente da dose e do manejo de aplicação, e seu efeito sobre as plantas de B. subquadripara foi temporário.This study aimed to evaluate the efficacy of the herbicide diquat in controlling Eichhornia crassipes and Brachiaria subquadripara plants under reservoir conditions. The experimental plots were 650 m², delimited and positioned on the shores of the Salto Grande Reservoir in Americana-SP, Brazil, using fishing nets. The treatments consisted of herbicide diquat, applied as the REWARD commercial formulation at 960 g a.i. ha-1 (two applications at 480 g, at an interval of 15 days, 960 g a.i. ha-1 (single application, 1.920 g a.i. ha-1 (two applications at 960 g, at an interval of 15 days and a control without herbicide application. The concentrations of diquat in water were

Atividade de fosfatases em gramíneas forrageiras em resposta à disponibilidade de fósforo no solo e à altura de corte das plantas Phosphatase activity in forage grasses as influenced by soil phosphorus availability and plant cutting height

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Flancer Novais Nunes

2008-10-01

Full Text Available A eficiência de utilização de um nutriente, expressa pela relação entre a biomassa produzida e a quantidade absorvida, é uma importante característica adaptativa das plantas, particularmente daquelas cultivadas em solos com baixa disponibilidade desse nutriente. Maior eficiência de utilização de P (EUP é conferida pela maior taxa de remobilização de P, que consiste na translocação desse nutriente para regiões de maior demanda metabólica na planta. Maiores taxas de remobilização têm sido associadas a maiores atividades das enzimas: fosfatase ácida (APase e ribonuclease (RNase. Neste trabalho, avaliou-se a atividade dessas enzimas em plantas de Brachiaria decumbens, pouco exigente, e de Panicum maximum cv. Tanzânia, mais exigente em P, cultivadas em solos que receberam diferentes doses desse nutriente e submetidas a diferentes alturas de corte. O ensaio foi realizado em casa de vegetação, utilizando amostra do horizonte B de um Latossolo Vermelho-Amarelo argiloso. Os tratamentos resultaram da combinação fatorial das duas gramíneas, das doses de 100, 200 e 500 mg dm-3 de P e das três alturas de corte: sem corte e corte a 15 e 30 cm a partir da superfície do solo para Brachiaria; e sem corte e corte a 20 e 40 cm para Panicum. As unidades experimentais consistiram de vasos com 10 dm³ de solo, com 10 plantas. Os resultados indicaram que não houve diferença significativa na produção de biomassa das duas gramíneas, mas a adição de P propiciou maior produção e maior teor desse nutriente na parte aérea de ambas. As plantas submetidas a cortes mais severos apresentaram menor produção e maiores teores de P na parte aérea. Ocorreu efeito negativo das doses de P na atividade da APase e da RNase nas duas forrageiras. As plantas cultivadas com a menor dose de P apresentaram maior atividade dessas enzimas e maior EUP. A atividade de ambas as fosfatases decresceu com a idade das plantas. No tratamento com o corte mais

Evaluación de dos especies de Leucaena, asociadas a Brachiaria brizantha y Clitoria ternatea en un sistema silvopastoril de Nayarit, México: I. Comportamiento agronómico Evaluation of two Leucaena species, associated to Brachiaria brizantha and Clitoria ternatea in a silvopastoral system from Nayarit, Mexico: I. Agronomic performance

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J Bugarín

2009-12-01

Full Text Available Con el objetivo de evaluar el comportamiento agronómico de dos especies de Leucaena, asociadas a Brachiaria brizantha y Clitoria ternatea en un sistema silvopastoril en la llanura costera norte del estado de Nayarit, en México, se desarrolló la presente investigación. Se utilizó un diseño de bloques al azar con cuatro repeticiones por tratamiento (proporción de leguminosa:gramínea: 1 L. leucocephala-B. brizantha (30:70; 2 L. glauca-B. brizantha (30:70; 3 L. leucocephala-B. brizantha- C. ternatea (28:52:20; 4 L. glauca-B. brizantha-C. ternatea (28:52:20; 5 B. brizantha (100. Con una frecuencia mensual se midió el crecimiento de las especies arbóreas, además de la supervivencia y el comportamiento de la relación leguminosa:gramínea en el sistema. L. glauca mostró una mayor altura (66 cm y diámetro (0,98 cm cuando se combinó con brachiaria y clitoria, y L. leucocephala un mayor número de ramas (8,7 y altura (4,5 cm. En la sobrevivencia se observaron valores de 70 a 80% después de un año de implementado el sistema. De acuerdo con los resultados se concluye que la mezcla de las leguminosas arbóreas con C. ternatea y B. brizantha es una importante opción en las condiciones ecológicas del trópico seco mexicano.This study was conducted with the objective of evaluating the agronomic performance of two Leucaena species, associated to Brachiaria brizantha and Clitoria ternatea in a silvopastoral system in the northern coastal prairie of the Nayarit state, Mexico. A randomized block design was used with four repetitions per treatment (legume:grass proportion: 1 L. leucocephala-B. brizantha (30:70; 2 L. glauca-B. brizantha (30:70; 3 L. leucocephala-B. brizantha- C. ternatea (28:52:20; 4 L. glauca-B. brizantha-C. ternatea (28:52:20; 5 B. brizantha (100. Tree growth was measured on a monthly basis, in addition to survival and the performance of the legume:grass relationship in the system. L. glauca showed more height (66 cm and diameter

Eficiência fotossintética de cultivares de cana-de-açúcar e de diferentes espécies de plantas daninhas após a aplicação do diuron Photosynthetic efficiency of sugarcane cultivars and weed species after diuron application

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M. Girotto

2012-09-01

Full Text Available O objetivo deste trabalho foi avaliar a eficiência fotossintética, através da taxa de transporte de elétrons, de seis espécies de plantas daninhas e três cultivares de cana-de-açúcar após aplicação do herbicida diuron em pós-emergência inicial. Os cultivares utilizados (PO8862, SP80-3280 e RB83-5486 foram cortados em gemas e plantados em vasos com capacidade de 12 litros. A semeadura das seis espécies de plantas daninhas - Brachiaria decumbens, Digitaria horizontalis, Panicum maximum, Ipomoea grandifolia, Ipomoea hederifolia e Merremia cissoides - foi realizada para obter 25 plantas por vaso. A aplicação do herbicida diuron em pós-emergência inicial das plantas daninhas e dos cultivares de cana-de-açúcar foi realizada na dose de 3,0 kg ha-1, com adição de 0,2% de surfatante. As avaliações da taxa de transporte de elétrons no fotossistema (ETR das plantas após a aplicação foram realizadas com auxílio de um fluorômetro portátil. Para as espécies de plantas daninhas, a ETR foi avaliada após intervalos de 2, 4, 24, 48, 72, 96 e 144 horas após a aplicação. Quanto aos cultivares de cana-de-açúcar, os intervalos avaliados foram de 2, 24, 48, 72, 120, 168 e 240 horas após a aplicação. De maneira geral, as reduções dos valores da ETR indicaram o nível de sensibilidade dos diferentes cultivares de cana-de-açúcar e das diferentes plantas daninhas ao diuron, e a intoxicação foi detectada antes ou mesmo sem a presença dos sintomas. A classificação da sensibilidade dos cultivares de cana-de-açúcar foi em ordem decrescente: PO-8862, SP80-3280 e RB83-5486; para as plantas daninhas, as espécies mais sensíveis foram M. cissoides, I. grandifolia e I. hederifolia, seguidas das gramíneas D. horizontalis, P. maximum e B. decumbens.The aim of this study was to assess the photosynthetic efficiency through electron transport rate (ETR of six weed species and three sugarcane cultivars after application of the

Estrutura do pasto de capim-braquiária com variação de alturas Structure of signal grass pasture with height variation

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Manoel Eduardo Rozalino Santos

2010-10-01

Full Text Available Este trabalho foi conduzido com o objetivo de avaliar as características estruturais da Brachiaria decumbens cv. Basilisk. Foram avaliadas quatro alturas de plantas (10, 20, 30 e 40 cm dentro de uma mesma pastagem, em um delineamento experimental de blocos casualizados com duas repetições. A variação na altura inicial das plantas no pasto de capim-braquiária apresentou resposta linear e negativa. As massas de lâmina foliar verde, colmo verde, material morto, forragem verde e forragem total aumentaram linearmente com a altura das plantas no pasto. Contrariamente, houve redução linear na relação lâminas foliares verdes/colmos verdes com a altura das plantas no pasto (de 1,16 para 0,58. A altura das plantas no pasto teve efeito mais pronunciado sobre o aumento das massas de colmo verde e material morto que sobre a massa de lâmina foliar verde. A densidade volumétrica de lâminas foliares verdes decresceu (de 97,09 para 39,07 kg/cm.ha de MS com a altura das plantas no pasto. Mesma resposta ocorreu para as densidades volumétricas de forragem verde (de 181,62 para 107,85 kg/cm.ha de MS e forragem total (de 283,39 para 195,72 kg/cm.ha de MS. Por outro lado, não houve efeito da altura das plantas no pasto sobre as densidades volumétricas de colmos verdes e material morto, que apresentaram valores médios de 80,95 e 95,61 kg/cm.ha de MS, respectivamente. A altura das plantas no pasto teve efeito quadrático sobre a interceptação de luz pelo dossel. Áreas da pastagem com alturas de 10, 20, 30 e 40 cm apresentaram valores de interceptação luminosa de 56,15; 85,16; 93,39 e 96,57%, respectivamente. Ocorre variação espacial e temporal na estrutura do pasto de B. decumbens manejado sob lotação contínua.This study was carried out aiming to evaluate the structural characteristics of Brachiaria decumbens cv. Basilisk pasture. Four heights of plants (10, 20, 30 and 40 cm were evaluated within the same grazing area in a randomized block

Evaluación de pasturas de Brachiaria decumbens solas o asociadas con Centrosema acutifolium con ganado de doble propósito: II. Evaluación de la productividad animal

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Ramírez Náder Luis Miguel

1991-12-01

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En la segunda parte de esta investigación se evaluaron el cambio de peso de las vacas, y sus crías; la producción de leche; y los índices de preñez al finalizar el ensayo. Se utilizaron 4 praderas de 4 ha cada una, dos establecidas con B. decumbens solo, y dos con B. decumbens asociado, las cuales fueron pastoreados en forma alterna cada 21 días, asignándose una carga fija de 1.5 animales/ha. Se emplearon 24 vacas con sus crías (15 de tipo racial Hartón del Valle y 9 del tipo racial Mestizo, divididas aleatoriamente en 2 grupos en un ensayo de tipo "continuo", en el cual los animales pastorearon siempre en la misma pastura  (tratamiento. La producción total de leche, ajustada (incluyendo los días de no ordeño y corregida por covarianza de la producción acumulada durante los tres primeros días de ordeño, fue significativamente mayor (24% de mayor producción al 5.6% de probabilidad, en la pastura asociada (680 kg, lactancia media de 236 días, que en la pastura sola (550 kg, lactancia media de 241 días. El cambio de peso vivo posparto de las vacas, medido después de 210 días de lactancia y corregido por covarianza del peso inicial, indicó una diferencia altamente significativa (P < 0.003 a favor de la pastura asociada, (466 vs 429 kg. El cambio de peso vivo de las crías, no presentó diferencias

Aplicação de fosfato natural e reciclagem de fósforo por milheto, braquiária, milho e soja Rock phosphate fertilization and phosphorus recycling by pearl millet, Brachiaria sp., corn and soybean

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José Salvador Simoneti Foloni

2008-06-01

Full Text Available Este trabalho teve por objetivo avaliar, comparativamente, a capacidade extratora de P da soja (Glycine max, milho (Zea mays, braquiária brizantha (Brachiaria brizantha e milheto (Pennisetum glaucum, submetidos a diferentes doses do fertilizante fosfatado natural fosforita Alvorada, em condições controladas. Utilizou-se um Argissolo Vermelho distroférrico de textura média, corrigido e adubado com N, K e micronutrientes. As espécies foram cultivadas em vasos de 18 dm³ por 50 dias em casa de vegetação, com aplicação de 0, 100, 200 e 400 kg ha-1 de P2O5. As quantidades de fosfato natural foram calculadas com base na teor total de P2O5. O milho, ao contrário da soja, respondeu positivamente ao aumento da dose de P2O5 via fosforita Alvorada. A Brachiaria brizantha cv. Marandu, apesar da menor produção de matéria seca em relação ao milheto, apresentou alta eficiência na absorção de P, mesmo com o fornecido deste nutriente por meio de fonte pouco solúvel. O milheto apresentou-se como importante espécie de cobertura do solo, graças ao alto potencial para produção de fitomassa e reciclagem de P num intervalo de tempo relativamente curto (50 dias.The objective of this experiment was to compare the ability of soybean (Glycine max, corn (Zea mays, Brachiaria brizantha cv. Marandu and pearl millet (Pennisetum glaucum for P-uptake, at different levels of the Alvorada natural rock phosphate, under controlled conditions. The soil used was a dystrophic Hapludalf (180 g kg-1 clay, which was limed and fertilized with N, K and micronutrients. The crops were grown in 18 dm³ pots for 50 days in a greenhouse, at different P2O5 rates (0, 100, 200, and 400 kg ha-1. The amount of rock phosphate was calculated based on the total P2O5 content. Contrasting to soybean, there was a positive response of maize to higher P2O5 doses. The dry matter production by Brachiaria brizantha cv. Marandu was lower than that observed for pearl millet, but it still

Chlorophyll evaluation methods in Brachiaria brizantha brs Piatã added with poultry litter compost

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Alexandre Antonio Pasqualini

2013-12-01

Full Text Available One of the major limitations for pastures high production is the low fertility of tropical soils. In general, the nutrient reposition through chemical fertilizers increases the cost of production and can unbalance the plant besides the environment pollution. Recycling solid residues from agribusiness is a sustainable alternative for farmers. Among the residues, the poultry litter (PL aerobically fermented is a very good bio fertilizer for pastures. The Piatã Grass (Brachiaria brizantha is a new option for the pasture market and can be used for bovine, equine or ovine. The fast diagnosis of the nutritional stage of this plant, based upon portable methods as the Dualex, measuring leaf light reflectance is a practical alternative.  By this way,  it is possible to offer to the herd high nutritional food, correcting eventual shortage, mainly nitrogen. Nitrogen nutrition is directely related to chlorophyll content in the leaf blade. This study aimed to verify the effects of doses of PL over total chlorophyll, in comparison to two methods of evaluation: Dualex Scientific 4.0 and Spectrophotometer Analysis according to Lichtenthaler & Wellburn (1983. The experiment was conducted in greenhouse conditions, at IZ, Nova Odessa, with a Haplortox soil, between May and July, 2013. Treatments consisted of five compost doses (PL: 0, 20, 40, 60 and 120 Mg ha-1, with the following chemical composition (%: 2.88 of N, 3.85 of P2O5, 2.50 of K2O, 9.06 of Ca and 1.16 of Mg. The experimental design was on randomized blocks with five replications. Data were analyzed using the GLM procedure of the SAS program. Chlorophyll data were taken from the third medium of the leaf blade from a third of the expanded leaf from the apical using the Dualex. At the same time, samples were harvested for the Spectrophotometer analyses according to methodology described by Lichtenthaler & Wellburn (1983. Total Chlorophyll amounts were increased with the higher doses of PL, adjusting

Carbon stocks and dynamics under improved tropical pasture and silvopastoral

NARCIS (Netherlands)

Mosquera Vidal, O.; Buurman, P.; Ramirez, B.L.; Amezquita, M.C.

2012-01-01

To evaluate the effect of land use change on soil organic carbon, the carbon contents and stocks of primary forest, degraded pasture, and four improved pasture systems in Colombian Amazonia were compared in a flat and a sloping landscape. The improved pastures were Brachiaria humidicola, and

Effects of Grazing Management in Brachiaria grass-forage Peanut Pastures on Canopy Structure and Forage Intake.

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Gomes, F K; Oliveira, M D B L; Homem, B G C; Boddey, R M; Bernardes, T F; Gionbelli, M P; Lara, M A S; Casagrande, D R

2018-06-13

Maintenance of mixed grass-legume pastures for stand longevity and improved animal utilization is a challenge in warm-season climates. The goal of this study was to assess grazing management on stand persistence, forage intake, and N balance of beef heifers grazing mixed pastures of Brachiaria brizantha and Arachis pintoi. A two-year experiment was carried out in Brazil, where four grazing management were assessed: rest period interrupted at 90%, 95%, and 100% of light interception (LI) and a fixed rest period of 42 days (90LI, 95LI, 100LI, and 42D, respectively). The LI were taken at 50 points at ground level and at five points above the canopy for each paddock using a canopy analyzer. For all treatments, the post-grazing stubble height was 15 cm. Botanical composition and canopy structure characteristics such as canopy height, forage mass, and vertical distribution of the morphological composition were evaluated pre-and post-grazing. Forage chemical composition, intake, and microbial synthesis were also determined. A randomized complete block design was used, considering the season of the year as a repeated measure over time. Grazing management and season were considered fixed, while block and year were considered random effects. In the summer, legume mass accounted for 19% of the canopy at 100LI, which was less than other treatments (a mean of 30%). The 100LI treatment had a greater grass stem mass compared with other treatments. In terms of vertical distribution for 100LI, 38.6% of the stem mass was above the stubble height, greater than the 5.7% for other treatments. The canopy structure limited neutral detergent fiber intake (P = 0.007) at 100LI (1.02% of BW/d), whereas 42D, 90LI, and 95LI treatments had NDF intake close to 1.2% of BW/d. The intake of digestible organic matter (OM; P = 0.007) and the ratio of crude protein/digestible OM (P < 0.001) were less at 100LI in relation to the other treatments. The production of microbial N (P < 0.001) and efficiency

Eficácia do herbicida glifosato-potássico submetido à chuva simulada após a aplicação Effects of rainfall on efficacy the potassium glyphosate in weeds

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Gustavo Martini

2003-01-01

Full Text Available Apesar de possuir boa ação herbicida, alguns fatores afetam a eficácia do glifosato e, nesse contexto, realizaram-se estudos buscando formulações mais eficazes. O experimento foi instalado em área do Campus da FCAV-UNESP, Jaboticabal (SP. Testou-se a formulação potássica de glifosato comparada com solução aquosa e grânulos dispersíveis em água à mesma dosagem (0,36 kg.ha-1 e.a em cinco intervalos (1, 2, 4, 6 e > 48 horas sem chuva após a aplicação, comparados com uma testemunha sem uso de herbicidas. Foram aplicados em pós-emergência sobre Brachiaria plantaginea, B. decumbens e Digitaria horizontalis. A aplicação foi feita com pulverizador costal a CO2, à pressão de 2,5 kg.cm-2, munido de barra com seis bicos DG 110.02 e consumo de calda equivalente a 200 L.ha-1. Realizaram-se cinco avaliações de porcentagem de controle em relação à testemunha infestada, atribuídas visualmente, até 42 dias após aplicação. Notou-se que o controle da formulação potássica sobre as espécies avaliadas foi mais precoce, necessitando apenas quatro horas após sua aplicação para se igualar ao intervalo superior a 48 horas sem chuva. As demais necessitaram de, no mínimo, seis horas de intervalo.In spite of possessing good herbicidal action, some factors affect the effectiveness of the glyphosate and, in that context, studies were accomplished looking for more effective formulations. The experiment was installed in area of FCAV-UNESP Campus, in Jaboticabal, São Paulo State. The potassium glyphosate formulation was compared to CS and WG formulations, at the same rate (0.36 kg.ha-1 a.e, in five intervals (1, 2 ,4 6 and 48 hours without rain after the application, compared to a control without herbicides. They were applied in post emergence on Brachiaria plantaginea, B. decumbens and Digitaria horizontalis. The herbicides were applied with costal sprayer, at a constant pressure (35 lbf/pol², with four nozzles DG 11002. The

Pérdidas de suelo y nutrientes bajo diferentes coberturas vegetales en la zona Andina de Colombia Soil and nutrient loss under different vegetation covers in Colombia's Andean region

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J. Alexander Rodríguez

2009-07-01

Full Text Available El estudio se realizó en la reserva natural El Ciprés, ubicada en la vereda Bellavista, municipio de El Dovio (Valle del Cauca. La vereda se encuentra en la zona Andina de la cordillera occidental, en el departamento del Valle del Cauca, entre 1700 y 1800 m.s.n.m., con una temperatura promedio de 18 °C. Según la clasificación climática de Holdridge, corresponde a una zona de bosque húmedo Montano Bajo, con una precipitación promedio entre 2500 y 2700 mm/año, una humedad relativa de 90% y una pendiente del suelo de 62%. Las mediciones se hicieron en parcelas de escorrentía de 32 m² cada una y siete tipos de coberturas: guadua (Guadua angustifolia Kunth, bosque secundario, pastura (Brachiaria decumbens, café (Coffea arabica; banco de proteína (Trichanthera gigantea, caña forrajera (Saccharum officinarum y cultivo limpio conformado por yuca (Manihot esculenta, maíz (Zea mays y arracacha (Arracacia zanthorrhiza Brancroft. Para la evaluación se midieron las pérdidas de suelo y los nutrientes calcio, magnesio, potasio y fósforo en un periodo de 7 meses. Los resultados mostraron diferencias (P Soil and nutrient (calcium, magnesium, potassium, phosphorus losses were measured over a 7-month period in the El Ciprés Natural Reserve, located in the Bellavista rural community, municipality of El Dovio, in the western cordillera of the Andes of the department of Valle del Cauca, Colombia. At 1700-1800 meters above sea level, the area presents an average temperature of 18 °C, an average annual precipitation of 2500-2700 mm, 90% relative humidity, and a 62% slope. According to the Holdridge climate classification system, it corresponds to a lower montane rain forest. Measurements were taken in runoff plots, each 32 m², with seven types of vegetation cover: giant bamboo (Guadua angustifolia Kunth; secondary forest; pastures (Brachiaria decumbens; coffee (Coffea arabica; protein bank (Trichanthera gigantea; forage cane (Saccharum officinarum

Effect of plant and fungous metabolites on Meloidogyne exigua Efeito de metabólitos vegetais e fúngicos sobre Meloidogyne exigua

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Daniel Rufino Amaral

2009-01-01

Full Text Available As nematodes cause great damage to Brazilian coffee production, effective methods to control these parasites are necessary. In a previous work Allium cepa L., Cajanus cajan (L. Mill., Crotalaria juncea L., Ficus elastica Roxb., Ruta graveolens L., Stylosanthes guianensis Aubl., Leucaena leucocephala (Lam. Dewit., Brachiaria decumbens Stapf., Catharanthus roseus G. Don, Tagetes minuta L., Ricinus communis L. and Coffea arabica L. produced active substances against Meloidogyne exigua Goeldi, a nematode widely disseminated through Brazilian coffee fields. Thus, aqueous extracts of such plants, collected in a different season from that of the previous work, as well as crude metabolites produced in liquid medium by Fusarium moniliforme Shelden and Cylindrocarpon magnusianum (Sacc. Woll., were submitted to in vitro assays with M. exigua second-stage juveniles (J2. All plants and fungi produced active substances against J2. Therefore, their metabolites were applied to six-month-old coffee plants inoculated with M. exigua. After 90 days in a greenhouse, those samples obtained from A. cepa, L. leucocephala, R. graveolens and F. moniliforme inhibited the production of galls and eggs by M. exigua, demonstrating potential to control such parasite.Os nematóides acarretam grandes perdas aos produtores brasileiros de café, sendo necessário o desenvolvimento de métodos eficientes para o seu controle. Em trabalho anterior, Allium cepa L., Cajanus cajan (L. Mill., Crotalaria juncea L., Ficus elastica Roxb., Ruta graveolens L., Stylosanthes guianensis Aubl., Leucaena leucocephala (Lam. Dewit., Brachiaria decumbens Stapf., Catharanthus roseus G. Don, Tagetes minuta L., Ricinus communis L. e Coffea arabica L. produziram substâncias ativas contra o nematóide Meloidogyne exigua Goeldi, que é amplamente disseminado pelos cafezais brasileiros. Dando continuidade a esse trabalho, extratos aquosos das plantas mencionadas, coletadas em época diferente daquela

Período de interferência de plantas daninhas em mandioca (Manihot esculenta no noroeste do Paraná Period of weed interference in cassava (Manihot esculenta in northwestern Parana

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D.F. Biffe

2010-01-01

Full Text Available A mandioca é uma exploração agrícola importante no Estado do Paraná. No entanto, há limitadas informações relacionadas à interferência das plantas daninhas nessa cultura. Objetivou-se com este trabalho estimar o período crítico de prevenção à interferência (PCPI na cultura da mandioca (variedade Fécula Branca, nas condições edafoclimáticas do noroeste do Paraná. O experimento foi dividido em dois grupos de tratamentos: com períodos crescentes na presença de plantas daninhas (PAI; e com períodos crescentes na ausência de plantas daninhas (PTPI. Foram identificadas as espécies de plantas daninhas e densidades de infestação na área e calculada a importância relativa (IR, avaliando-se também o estande da cultura e a produtividade de raízes comerciais. As principais plantas daninhas presentes na área e que apresentaram os maiores valores de IR foram Cenchrus echinatus e Brachiaria decumbens. Aceitando-se uma tolerância de redução de produtividade de 5%, o PAI ajustado foi de 18 dias após o plantio da cultura, e o PTPI, de 100 dias. Concluiu-se que o PCPI da cultura para as condições edafoclimáticas do noroeste do Paraná situa-se entre 18 e 100 dias após o plantio.Although cassava is a major agribusiness crop in Paraná, technical information related to weed interference in this crop is limited. This work aimed to evaluate the critical period of weed interference (PCPI in cassava (var. Fécula Branca, for local climate and soil under northwestern Paraná conditions. The experiment was constituted of two groups: the first with increasing periods of weed interference (PAI and the second with increasing periods without weed interference (PTPI. Main weed species in the area were identified and accounted for densities and relative importance (RI during the cycle; crop stand and commercial root yield were also evaluated. The highest RI values were found for Cenchrus echinatus and Brachiaria decumbens. Considering a

Composição corporal e exigências líquidas de macrominerais para ganho de peso em bovinos 5/8 Holandês-Zebu em pastejo na zona da mata de Pernambuco Body composition and net requirements of macrominerals for gain of 5/8 crossbreed bulls under grazing in coastal area of Pernambuco state

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Dulciene Karla Bezerra de Andrade

2008-05-01

Full Text Available Avaliaram-se a composição corporal e as exigências líquidas dos macroelementos minerais cálcio (Ca, fósforo (P, magnésio (Mg e potássio (K para ganho de peso em bovinos mestiços 5/8 Holandês-Zebu criados em pastagem de Brachiaria decumbens Spaft. Foram utilizados 16 animais com 10 meses de idade e peso vivo de 180 ± 19,95 kg. Os tratamentos foram livre acesso ao pasto e pastejo restrito, todos com suplementação com mistura mineral comercial. Quatro animais foram abatidos no início do experimento e serviram como referência à estimativa de peso do corpo vazio (PCVZ e da composição corporal inicial dos animais remanescentes. Os outros animais foram abatidos aos 84 dias do período experimental. Ajustaram-se as equações do logaritmo dos conteúdos corporais de Ca, P, Mg e K em função do logaritmo do PCVZ, para cada tratamento. Derivando-se essas equações estimaram-se as exigências líquidas de Ca, P, Mg e K para ganho de peso. As exigências líquidas dos macrominerais estudados (Ca, P, Mg e K decresceram à medida que o peso aumentou. As exigências líquidas de Ca e P diferiram das preconizadas pelos comitês internacionais britânico e americano de exigências nutricionais.The objective was to evaluate the body composition and net requirements of the macro minerals calcium (Ca, phosphorus (P, magnesium (Mg and potassium (K for weight gain in 5/8 crossbreed Holstein-Zebu cattle maintained in pasture Brachiaria decumbens Stapf. Sixteen animals were used with 10 month of age and 180 ± 19.95 kg BW. The treatments were open access to pasture and restricted grazing, both supplemented with commercial mineral salt. Four animals slaughtered in the beginning of the experiment to serve as reference for the estimation of empty body weight (EBWi and initial body composition of the remaining animals. The others animals were slaughtered at 84 days of the experimental period. Regressions equation of the logarithm of Ca, P, Mg, and K of

Correção da acidez do solo e controle do capim-sapé Soil acidity correction and control of sapé-grass

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Margarida Mesquita Carvalho

2000-02-01

Full Text Available RESUMO - Um experimento de campo foi realizado para verificar o efeito da correção da acidez do solo sobre o controle do capim-sapé (Imperata brasiliensis, gramínea invasora de pastagens. Pastagem de capim-gordura (Melinis minutiflora em Latossolo Vermelho-Amarelo, com intensa infestação de capim-sapé foi usada. Os tratamentos consistiram de cinco doses de calcário dolomítico (0, 1, 2, 4 e 6 t/ha, incorporado ao solo manualmente com auxílio de enxada, à profundidade de 20 cm, após gradagem das parcelas. Um tratamento extra, sem calcário e gradagem foi adotado. O delineamento experimental foi em blocos ao acaso com quatro repetições. No período de 33 meses de duração do experimento, foram feitos três cortes da vegetação aérea e duas amostragens de solo. Não houve efeito das doses de calcário sobre a produção de matéria seca do capim-sapé e das outras espécies (capim-gordura, Brachiaria decumbens e invasoras de folhas largas, apesar de terem ocorrido alterações nas características químicas do solo. A correção da acidez do solo, quando associada às correções das principais deficiências nutricionais, pode controlar o capim-sapé, ao estimular o crescimento das forrageiras.ABSTRACT - A field experiment was conducted to determine the effect of acid soil correction, on the control of the sapé (Imperata brasiliensis, a grass type weed of pasture. A molasses grass (Melinis minutiflora pasture in a red-yellow latosol, having a high proportion of "sapé" was used. Treatments consisted of five levels of dolomite limestone (0, 1, 2, 4 and 6 t/ha incorporated by hand using a garden tool to the top 20 cm of soil following a mechanical tillage of the plots (disking. An additional treatment without disking and without lime was adopted. The experimental design was randomized blocks with four replications. During the 33 months of the experimental period, three harvests and two soil samplings were performed. There were no

Análise comparativa de fragmentos identificáveis de forrageiras, pela técnica micro-histológica Comparative analysis of identifiable fragments of forages, by the microhistological technique

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Maristela de Oliveira Bauer

2005-12-01

Full Text Available Objetivou-se, com este trabalho, verificar, pela técnica micro-histológica, diferenças entre espécies forrageiras quanto ao percentual de fragmentos identificáveis, em função do processo digestivo e da época do ano. Lâminas foliares frescas recém-expandidas, correspondentes à última e à penúltima posição no perfilho, das espécies Melinis minutiflora Pal. de Beauv (capim-gordura, Hyparrhenia rufa (Nees Stapf. (capim-jaraguá, Brachiaria decumbens Stapf. (capim-braquiária, Imperata brasiliensis Trin. (capim-sapé, de Medicago sativa L. (alfafa e de Schinus terebenthifolius Raddi (aroeira, amostradas nos períodos chuvoso e seco, foram digeridas in vitro e preparadas de acordo com a técnica micro-histológica. Observou-se que as espécies apresentaram diferenças marcantes na porcentagem de fragmentos identificáveis e que a digestão alterou estas porcentagens em torno de 10 %; que o período de amos­tragem não influenciou a porcentagem de fragmentos identificáveis para a maioria das espécies; que a presença de pigmentos e a adesão da epiderme às células dos tecidos internos da folha prejudicaram a identificação dos fragmentos; e que a digestão melhorou a visualização dos fragmentos dos capins sapé e jaraguá e da aroeira, mas prejudicou a do capim-braquiária e, principalmente, a da alfafa.The objetive of this study was to verify differences among forages species in relation to the percentage of identifiable fragment as affected by the digestion process and season. Fresh last expanded leaf lamina samples of the species Melinis minutiflora Pal. de Beauv (Molassesgrass, Hyparrhenia rufa (Nees Stapf. (Jaraguagrass, Brachiaria decumbens Stapf. (Signalgrass, Imperata brasilienses Trin. (Sapegrass, and foliar laminas of Medicago sativa L. (Alfalfa and Schinus terebenthifolius Raddi (Aroeira, sampled in the rainy and dry seasons, were digested in vitro and prepared according to the microhistological technique. The

Efecto de los métodos de cosecha y secado de la semilla de Brachiaria dictyoneura en su microflora y calidad (viabilidad y germinación

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Lenne Jilliam M.

1988-12-01

Full Text Available Se evaluó el efecto de los métodos de cosecha con sudado (cosecha manual pila horizontal sometida a 3 días de sudado, cosecha manual pila vertical a 3 días, 6 días y 9 días de sudado, cosecha manual pila apretada a 3 días de sudado, sin sudado (cosecha manual sin sudado, cosecha con combinada y de la mezcla fungicida (Benlate + Difolatan sobre microflora, viabilidad y germinación de las semillas de Brachiaria dictyoneura. Para la determinación de la viabilidad se utilizó el método topográfico del tetrazolio, en las pruebas de germinación se utilizaron cuatro técnicas para romper latencia de las semillas (H20, H2S04, KN03 Y H2S04 + KN03.In this work, the effect of harvesting methods with sweating (manual harvesting horizontal pile exposed to 3 days sweating, manual harvesting vertical pile at 3,6 and 9 days sweating, manual harvesting disturbed pile at 3 days sweating; without sweating (manual harvest without sweating, combine harvesting and of a mixture of fungicides (Benlate and Difolatan on the microflora, viability and germination of the seeds of Brachiaria dictyoneura was evaluated. In order to determine the viability the topographical method of tetrazolium was used, in the germination test four methods to break latency of seeds were used H20, H2S04, KN03 and H2S04 + KN03.

Interferência de plantas daninhas sobre o crescimento inicial de Coffea arabica Weed effect on the initial growth of Coffea arabica

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C.M.T. Fialho

2011-03-01

Full Text Available Objetivou-se com este trabalho avaliar os efeitos da interferência de plantas daninhas, em diferentes densidades de infestação, sobre o crescimento de plantas jovens de café arábica. Mudas de café, cultivar Mundo Novo, foram transplantadas, no estádio de quatro a cinco pares de folhas completamente expandidas, para vasos com capacidade de 25 dm³. O experimento foi conduzido em casa de vegetação em blocos casualizados, em esquema fatorial (4 x 4; o primeiro fator foi composto por espécies de plantas daninhas (Digitaria horizontalis, Brachiaria decumbens, Brachiaria plantaginea e Mucuna aterrima, e o segundo, por densidades dessas espécies (zero, dois, quatro e seis plantas por vaso, com quatro repetições. O plantio das espécies daninhas foi realizado 60 dias após o transplantio do café (0 DAT. Nesta data e no dia do encerramento do experimento, aos 90 DAT, determinaram-se a altura, a área foliar e o diâmetro do caule da planta de café, para cálculo do incremento dessas variáveis. Aos 90 DAT, determinou-se a matéria seca da parte aérea e radicular do café e das plantas daninhas e a densidade radicular do café. Utilizando esses resultados, estimou-se a razão de massa foliar, razão de massa caulinar, razão de massa radicular, razão de área foliar e a razão sistema radicular/parte aérea das plantas de café. A espécie M. aterrima foi a que mais reduziu a taxa de crescimento, a área foliar, a matéria seca do caule e das folhas e o diâmetro do caule do café. Entre as gramíneas, B. plantaginea foi a que mais reduziu a taxa de crescimento, área foliar, diâmetro do caule e densidade radicular do café. Ocorreu relação negativa entre a densidade de plantas daninhas e as variáveis de crescimento e com a razão de massa radicular e razão sistema radicular/parte aérea.The goal of this work was to evaluate the effects of weeds on the growth of young Arabica coffee plants, at different densities of infestation

Legumes and forage species sole or intercropped with corn in soybean-corn succession in midwestern Brazil Espécies leguminosas e forrageiras, solteiras ou consorciadas com milho, na sucessão soja-milho no centro-oeste do Brasil

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Gessí Ceccon

2013-02-01

Full Text Available The feasibility of no-tillage in the Cerrado (Savanna-like vegetation of Brazil depends on the production of sufficient above-ground crop residue, which can be increased by corn-forage intercropping. This study evaluated how above-ground crop residue production and yields of soybean and late-season corn in a soybean-corn rotation were influenced by the following crops in the year before soybean: corn (Zea mays L. intercropped with Brachiaria (Urochloa brizantha cv. Marandu, B. decumbens cv. Basilisk, B. ruziziensis, cv. comum., Panicummaximum cv. Tanzânia, sunn hemp (Crotalaria juncea L., pigeon pea [Cajanus cajan (L. Millsp]; sole corn, forage sorghum [Sorghum bicolor (L. Moench (cv. Santa Elisa], and ruzi grass. In March 2005, corn and forage species were planted in alternate rows spaced 0.90 m apart, and sole forage species were planted in rows spaced 0.45 m apart. In October 2005, the forages were killed with glyphosate and soybean was planted. After the soybean harvest in March 2006, sole late-season corn was planted in the entire experimental area. Corn grain and stover yields were unaffected by intercropping. Above-ground crop residue was greater when corn was intercropped with Tanzania grass (10.7 Mg ha-1, Marandu (10.1 Mg ha-1, and Ruzi Grass (9.8 Mg ha-1 than when corn was not intercropped (4.0 Mg ha-1. The intercropped treatments increased the percentage of soil surface covered with crop residue. Soybean and corn grain yields were higher after sole ruzi grass and intercropped ruzi grass than after other crops. The intercropping corn with Brachiaria spp. and corn with Panicum spp. increases above-ground crop residue production and maintains nutrients in the soil without reducing late-season corn yield and the viability of no-till in the midwestern region of Brazil.A viabilidade do plantio direto no Cerrado brasileiro depende da produção adequada de palha das culturas, que pode ser aumentada pela consorciação de milho (Zea mays L

Efeito do fósforo suplementar sobre o desempenho reprodutivo de vacas de corte em pastagem de Brachiaria humidicola Effect of phosphorus supplementation on the reproductive performance of beef cows grazing Brachiaria humidicola

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LUIZ ROBERTO LOPES S'THIAGO

2000-02-01

Full Text Available O objetivo deste experimento foi observar e quantificar o efeito de duas misturas minerais (ad libitum, uma sem (M e outra com fósforo suplementar (MP, sobre o desempenho produtivo e reprodutivo de vacas de cria neloradas em pastejo de Brachiaria humidicola. O trabalho foi realizado na Fazenda Modelo (Embrapa-Centro Nacional de Pesquisa de Gado de Corte, localizada em Terenos, MS, em duas fases, a primeira, em 1988/92, e a segunda, em 1992/94. Na segunda fase, reduziu-se a carga animal durante a seca e os dias de amamentação (de 1,0 para 0,5 vacas/ha e de 210 para 90 dias, respectivamente. Foram realizadas medidas de consumo da mistura mineral (M = 76 e MP = 112 g/cab./dia; teor médio de fósforo na forrageira (época das chuvas = 0,16%, época seca = 0,11%; peso vivo (primeira fase: M = 363±3,3 e MP = 371±3,8 kg; segunda fase: M = 407± 5,7 e MP = 417± 6,5 kg; taxa de natalidade (primeira fase: M = 67±3,3 e MP = 66± 3,5%; segunda fase: M = 74± 6,3 e MP = 80± 5,7% e bezerros desmamados (primeira fase: M = 86± 5,0 e MP = 91± 5,3; segunda fase: M = 55± 6,4 e MP = 67± 5,7. As vacas de cria não responderam ao fósforo suplementar.The objective of this experiment was to observe and quantify the effect of two mineral mixtures, as free-choice feeding, one without (M and other with phosphorus supplement (MP, on the productive and reproductive performance of Nellore beef cows grazing Brachiaria humidicola. This work was conducted at the Fazenda Modelo (Embrapa-Centro Nacional de Pesquisa de Gado de Corte, located in Terenos, MS, Brazil, in two phases, 1st from 1988/92 and 2nd from 1992/94. During the 2nd phase, stocking rate, for the dry period, and suckling days were reduced (from 1.0 to 0.5 cows/ha and 210 to 90 days, respectively. Mineral intake (M = 76 and MP = 112 g/had/day, forage phosphorus level (wet season = 0.16%; dry season = 0.11%, liveweight (1st phase: M = 363± 3.3 and MP = 371± 3.8 kg; 2nd phase: M = 407± 5.7 and MP

Tiller classes on signalgrass pasture according to the cattle droppings position

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Manoel Eduardo Rozalino Santos

2010-01-01

Full Text Available The experiment was carried out aiming to investigate the influence of natural deposition of cattle droppings on population density of several classes of tillers on the Brachiaria decumbens Stapf. cv. Basilisk pasture managed under continuous stocking. Two places on the same pasture were evaluated: one near (immediately adjacent and one far, about 1.0 m, from the cattle droppings. Randomized block design with three repetitions was used. Tillers were classified according to the developmental stage, growth origin, defoliation rate and length. The number of vegetative tillers was higher (P<0.05 at the place that was far from the droppings (1.851 perfilhos/ m2 than at the one near them (848 perfilhos/m2. The number of reproductive tillers was higher (P<0.05 at the place near the droppings. Being near or far from the droppings showed no impact on the population density of dead tillers (584 perfilhos/m2 mean. The number of basal tiller and aerial tillers were higher (P<0.05 at the place far from the droppings, when collated to the place near the droppings. The population densities of both defoliated tillers and tillers without shoot meristem, far from the droppings, were higher (P<0.05, while the population density of nondefoliated tillers was higher (P<0.05 at the place found near the droppings. The shortest tillers were common (P<0.05 at the place far from the droppings, while the highest were frequently found (P<0.05 near the droppings. In the B. decumbens pasture under continuous stocking, deposition of droppings by cattle changes the spatial distribution of tillers categories and thus constitutes a factor causing spatial heterogeneity of vegetation.

Consórcio sorgo e braquiária na entrelinha para produção de grãos, forragem e palhada na entressafra

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Alessandro Guerra da Silva

2014-10-01

Full Text Available O consórcio tem sido utilizado para produção de grãos e forragem, porém poucos estudos foram realizados com a cultura do sorgo granífero na região Centro-Oeste. Portanto, o objetivo deste trabalho foi o de identificar, na safrinha, o consórcio de sorgo e braquiária, implantadas em duas profundidades de semeadura, que proporcione maiores rendimentos de grãos, massa seca (palhada e proteína bruta (forragem com dois cortes nas plantas de braquiária na entressafra. O ensaio foi instalado a campo, em Rio Verde-GO em 05 de março de 2009. Utilizou-se o delineamento experimental de blocos casualizados em esquema fatorial 2x3+1+3, correspondendo a duas profundidades de semeadura da braquiária (2 e 10 cm e três espécies de braquiária (Brachiaria decumbens (Staf, B. brizantha (Hoschst cv. Marandu e B. ruziziensis Germain et Evrard semeadas na entrelinha do sorgo granífero DKB 599, além de quatro tratamentos adicionais sendo um para o monocultivo de sorgo e outros três para cada espécie de braquiária. Os resultados permitiram constatar que o consórcio do sorgo granífero com braquiária na entrelinha apresentou potencial para produção de grãos (exceto da associação com a B. decumbens, semeada a 10 cm de profundidade, e com a B. ruziziensis, semeada a 2 cm, massa seca e proteína bruta, demonstrando a viabilidade para o sistema de cultivo em plantio direto na região Central do Brasil.

Forage intake and botanical composition of feed for cattle fed Brachiaria/legume mixtures Consumo e composição da forragem ingerida por bovinos alimentados com Brachiaria e uma leguminosa

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Robert Macedo

2010-08-01

Full Text Available A key contribution to study the cycling of nutrients in soil/plant/animal systems is the evaluation of the consumption of forage and their nutrients by cattle. The objective of this study was to test techniques to evaluate faecal production, in vitro digestibility, forage consumption and the proportion of legume in the acquired diet. Five Zebu steer calves were confined and fed five diets of different combinations of Brachiaria dictyoneura and Desmodium ovalifolium. All quantities of faeces were collected per animal and these values were found to compare favourably with those derived from using the chromium oxide technique. In vitro digestibility ranged from 7 to 10% higher than the actual in vivo digestibility. Faecal samples from steers fed with diets with 25% or more of grass in the mixture were found to be depleted in δ13C between 1.7 and 2.1‰, but no depletion was observed when the diet was 100% D. ovalifolium. There was a positive linear regression (r² = 0.97*** of the δ13C of the diet with the δ13C of faeces, but if the acquired diet contained a very high proportion of legume, the legume content could be underestimated by as much as 10%. None of the internal indicators, such as lignin or ash content of the diets, were useful to predict feed intake, but the chromium oxide external indicator performed satisfactorily. The 13C analysis of the faeces was an effective predictor of the proportion of the legume in the consumed diet.Uma contribuição fundamental para o estudo da ciclagem de nutrientes no sistema solo/planta/ animal é a avaliação do consumo pelo gado de forragem e dos nutrientes nela contidos. Testaram-se, sob condições controladas, técnicas para avaliar a produção fecal, digestibilidade in vitro, consumo de forragem e a proporção de leguminosa ingerida na dieta. Cinco novilhos de Zebu foram confinados e alimentados com quantidades conhecidas de cinco rações com diferentes proporções de Brachiaria dictyoneura e

Respostas de Acacia mangium Willd e Sclerolobium paniculatum Vogel a fungos micorrízicos arbusculares nativos provenientes de áreas degradadas pela mineração de bauxita na Amazônia Responses of Acacia mangium Willd and Sclerolobium paniculatum Vogel to native arbuscular mycorrhizal fungi from remaining areas of bauxite mining in Amazon

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Ney Freitas Marinho

2004-03-01

were the number of spores in the soil, the mycorrhizal colonization, the total dry matter, accumulated P, the mycorrhizal dependence of the seedlings and the abundance and the frequency of species. The number of infective propagules (NIP was studied in a randomized block design, with eight dilutions of soil inoculum, five replicates and a trap plant (Brachiaria decumbens Stapf. Substratum of a Planosol, mixed with washed sand (1:1 v:v, and phosphate of rock Araxá (0.60 g/kg was used. The number of spores increased in function of time covering of legumes. The mycorrhizal colonization was more intense in tachi. The values of dry matter of that species were inferior to the mangium, that extracted six times larger P of substratum. In general, mangium, contrary to tachi, was facultative to presence of AMF, suggesting the use in degraded areas without previous inoculation. Among the 39 species of identified AMF, Glomus macrocarpum Tul. & Tul. showed higher index of abundance and frequency (IAF and higher NIP, standing among pioneering species, while others appeared only under more developed forest of the areas in reclamation.

Tóxidad de cadmio y plomo en pasto tanner Brachiaria arrecta

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Manuel Peláez

2014-12-01

Full Text Available Se evaluó fisiopatías en Brachiaria arrecta expuestas a contenidos tóxicos de cadmio y plomo en el invernadero de la Universidad Nacional de Colombia Sede Palmira, se doparon plántulas sanas de 20 días de edad bajo cultivo hidropónico. El objetivo fue describir síntomas crecientes por intoxicación con el diseño de una escala valorativa de daños crecientes, adicionalmente se evaluaron cambios histológicos de raíz tallo y hojas mediante microscopia de luz de alta resolución (MLAR. Las plantas fueron sometidas a estrés abiótico con los tratamientos de sales de CdCl2 en concentración de 10 ppm, y de Pb (NO32 500 ppm, respectivamente. Los resultados principales mostraron un mayor detrimento cuando las plantas fueron expuestas al metal plomo que al cadmio en las raíces, tallos y hojas. Se apreciaron deformaciones extremas en paredes celulares de las células del cortex y en la endodermis de la raíz; en las hojas los daños fueron notorios para ambos metales sobre todo en el parénquima clorofílico y en la deformación de paredes de la epidermis tanto en haz como envés; en los tallos aparecieron deformaciones de las células del parénquima de relleno cuando ocurre bioacumulación intensa de plomo. Estos resultados sugieren que la bioconcentración en los tejidos vegetales ocasiona trastornos histológicos, que pueden involucrar una red trófica y por consiguiente consecuencias en la Salud Pública.

Interferência e nível de dano econômico de Brachiaria plantaginea e Ipomoea nil na cultura do feijão comum Interference and economic threshold of Brachiaria plantaginea and Ipomoea nil in the common bean crop

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Ribas Antonio Vidal

2010-08-01

Full Text Available As pesquisas acerca do impacto da interferência das plantas daninhas sobre as culturas normalmente são realizadas com uma única espécie infestante, quando na realidade podem ocorrer diversas. Os objetivos deste trabalho foram avaliar a interferência de Brachiaria plantaginea e Ipomoea nil sobre o rendimento de grãos do feijoeiro (Phaseolus vulgaris e determinar o nível de dano econômico (NDE de cada espécie na cultura. Foram realizados dois experimentos a campo com as cultivares de feijão 'IPR Graúna' (Grupo Preto e 'UTF-06' (Grupo Carioca em convivência com infestações mistas em diferentes proporções aleatórias das espécies B. plantaginea e I. nil. Modelos de regressão múltiplos foram utilizados para determinar a capacidade de interferência de cada espécie daninha sobre a produtividade da cultura. O impacto de interferência de cada planta de I. nil correspondeu a 2,6 e 0,25 quando comparada a cada planta de B. plantaginea, dependente das proporções relativas na comunidade infestante e das condições de cada experimento. A cultivar 'IPR Graúna' apresentou maior habilidade competitiva do que 'UTF-06'. O NDE foi dependente da proporção relativa de cada espécie daninha na comunidade e foi obtido sob baixas infestações (The researches about the impact of weed interference on crops are usually performed with a single weed species, when in reality there are numerous. The objective of this study was to evaluate the interference of Brachiaria plantaginea and Ipomoea nil on the grain yield of French beans (Phaseolus vulgaris and to determine the economic weed threshold (EWT of each species on the crop. Two field experiments were conducted with bean cultivars 'IPR Graúna' (Black group and 'UTF-06' (Carioca group in coexistence with random proportions of mixed infestations of B. plantaginea and I. nil. Multiple regression models were used to determine the interference abi1lity of each weed species on crop productivity. The

Legumes and forage species sole or intercropped with corn in soybean-corn succession in midwestern Brazil

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Gessí Ceccon

2013-02-01

Full Text Available The feasibility of no-tillage in the Cerrado (Savanna-like vegetation of Brazil depends on the production of sufficient above-ground crop residue, which can be increased by corn-forage intercropping. This study evaluated how above-ground crop residue production and yields of soybean and late-season corn in a soybean-corn rotation were influenced by the following crops in the year before soybean: corn (Zea mays L. intercropped with Brachiaria (Urochloa brizantha cv. Marandu, B. decumbens cv. Basilisk, B. ruziziensis, cv. comum., Panicummaximum cv. Tanzânia, sunn hemp (Crotalaria juncea L., pigeon pea [Cajanus cajan (L. Millsp]; sole corn, forage sorghum [Sorghum bicolor (L. Moench (cv. Santa Elisa], and ruzi grass. In March 2005, corn and forage species were planted in alternate rows spaced 0.90 m apart, and sole forage species were planted in rows spaced 0.45 m apart. In October 2005, the forages were killed with glyphosate and soybean was planted. After the soybean harvest in March 2006, sole late-season corn was planted in the entire experimental area. Corn grain and stover yields were unaffected by intercropping. Above-ground crop residue was greater when corn was intercropped with Tanzania grass (10.7 Mg ha-1, Marandu (10.1 Mg ha-1, and Ruzi Grass (9.8 Mg ha-1 than when corn was not intercropped (4.0 Mg ha-1. The intercropped treatments increased the percentage of soil surface covered with crop residue. Soybean and corn grain yields were higher after sole ruzi grass and intercropped ruzi grass than after other crops. The intercropping corn with Brachiaria spp. and corn with Panicum spp. increases above-ground crop residue production and maintains nutrients in the soil without reducing late-season corn yield and the viability of no-till in the midwestern region of Brazil.

Growth and biomass allocation of the C4 grasses Brachiaria brizantha and B. humidicola under shade Crescimento e alocação de biomassa nas gramíneas C4 Brachiaria brizantha e B. humidicola sob sombreamento

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MOACYR BERNARDINO DIAS-FILHO

2000-12-01

Full Text Available The growth and biomass allocation responses of the tropical forage grasses Brachiaria brizantha cv. Marandu and B. humidicola were compared for plants grown outdoors, in pots, in full sunlight and those shaded to 30% of full sunlight over a 30day period. The objective was to evaluate the acclimation capacity of these species to low light. Both species were able to quickly develop phenotypic adjustments in response to low light. Specific leaf area and leaf area ratio were higher for low-light plants during the entire experimental period. Low-light plants allocated significantly less biomass to root and more to leaf tissue than high-light plants. However, the biomass allocation pattern to culms was different for the two species under low light: it increased in B. brizantha, but decreased in B. humidicola, probably as a reflection of the growth habits of these species. Relative growth rate and tillering were higher in high-light plants. Leaf elongation rate was significantly increased on both species under low light; however, the difference between treatments was higher in B. brizantha. These results are discussed in relation to the pasture management implications.O crescimento e a alocação de biomassa das gramíneas forrageiras tropicais Brachiaria brizantha cv. Marandu e B. humidicola foram comparados, em plantas cultivadas em vasos, a pleno sol e a 70% de interceptação da luz solar, durante um período de 30 dias. O objetivo foi avaliar a capacidade de aclimatação dessas espécies ao sombreamento. Ambas as espécies mostraram-se capazes de desenvolver rapidamente ajustes fenotípicos em resposta ao sombreamento. A área foliar específica e a razão de área foliar foram maiores durante todo o período experimental, nas plantas cultivadas à sombra. As plantas sombreadas alocaram significativamente menos biomassa nas raízes e mais nas folhas do que as plantas cultivadas à sombra. No entanto, a alocação de biomassa no colmo foi

Assessment of land use in protected areas of the state of Sao Paulo, Brazil

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Iori, P.; da Silva, R. B.; Dias Junior, M. S.; Paz González, A.

2012-04-01

It is of universal knowledge that the soil, a basic natural resource, is renewable only if conserved or used correctly(Primavesi, 2002). It is salient for Araújo et al. (2007) that the establishment of index of soil quality is an important tool in the functions of control, supervision and monitoring of areas for environmental protection. The objective of this study was to compare the quality of the soil by means of a comparative diagram in different soil uses in permanent preservation areas (APP). The study was conducted in areas near the Ribeira de Iguape river in the city of Registro - São Paulo - Brazil, belonging to the Atlantic Forest domain, a Haplic Cambisol. The following uses of the soil had been evaluated: a) banana culture (CBAN) without agricultural traffic of machines; b) degraded pasture (PDEG) with extensive system predominantly Brachiaria decumbens L. c) use silvopastoral (MPIs), consisted in a kills with a traffic free for the animals, and d) native vegetation (MNAT), proposed in this study as a reference area.The following physical indicators were analyzed: bulk density (BD), total soil porosity (TP), macroporosity (Ma), microporosity (Mi), water dispersible clay (ADA), flocculation index (FI), preconsolidation pressure (PP), soil shear strength (SS), soil resistance to penetration (RP). To construct the comparative diagram the values for each attribute of the soil in each land use were related to the values of the native forest. It was feasible to use the comparative model in the qualitative evaluation of soil use, allowing separate environments under different uses. According to the comparative diagram of banana culture is the use that most negatively impacts the physical and mechanical soil due to the smaller size of the lower polygon.

Morphophysiology and nutritive value of signalgrass in silvipastoral system with different tree arrangements

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Joysiene Sanguinete Coelho

2014-06-01

Full Text Available The study was carried out with the aim to evaluate the effect of different special arrangements in forage yield, nutritive value and structure of the understory of signalgrass (Brachiaria decumbens in silvipastoral system with different regrowth times. The design was in complete randomized block with tree replicates in a factorial scheme with split-plots 2 × 2 × 5 consisting two spatial arrangements [Double lines 9 × (2 × 2m and simple lines (9 × 2m] in two sampling places (in the middle of the intercropping and under the three canopy in the plot and five regrowth times (35, 42, 49, 56 e 63 days in the split-plot. It was used a silvipastoral system established since June, 2008 in degraded pasture with signalgrass predominance. The pasture was homogenized by grazing at 15 cm from the soil level. Were evaluated the dry matter yield leaf:stem ratio, light interception and leaf area index. In addition were evaluated the nutritive value characteristics dry matter content, neutral and acid detergent fiber, crude protein and lignin. The photosynthetic active radiation was monitored. The use of simple or double lines did not influence the leaf area index, light interception and dry mass yield. The leaf:stem ratio was influenced by the sampling place only in the double line arrangement. The neutral detergent fiber was substantially high in the double line arrangement. Therefore, the use of double lines reduces the photosynthetic active radiation amount incident in the understory, but does not reduce the forage yield in relation to simple line arrangements. These results indicate the use of double lines arrangement may allow the harvest of more threes without reduce the pasture production.

Adsorption of P and forms of iron in no-tillage areas in the ‘Cerrado’ biome

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Marcos Gervasio Pereira

2014-11-01

Full Text Available The objective of this study was to evaluate the forms of iron extracted as sodium dithionite-citrate-bicarbonate (Fed, acid ammonium oxalate (Feo and sodium pyrophosphate (Fep and the relationship between these variables and the total organic carbon content and maximum adsorption capacity of P (MACP. The areas selected for this study had been using a no-tillage system (NTS for varying periods of time: 3 years (NTS3, 15 years (NTS15 and 20 years (NTS20. These areas were compared with an area of native ‘Cerrado’ (CE and a pasture area planted with Brachiaria decumbens (PA. The soil of the areas studied was classified as dystrophic oxisol. In each area, samples were collected at 0–5 cm and 5–10 cm. A correlation was observed between the C content and the different forms of Fe in the areas studied. There was a significant positive correlation between the carbon content and the forms of iron (Feo, Feo/Fed and Fep and a negative correlation with the level of Fed. The areas of CE and PA had the highest MACP, which diminished as the amount of time of NTS use increased.

Defoliation patterns in signal grass tillers with varying heights in the same pasture - doi: 10.4025/actascianimsci.v35i3.14376

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Simone Pedro da Silva

2013-07-01

Full Text Available The experiment was carried out to evaluate the patterns of defoliation in plants of various heights in the same pasture of Brachiaria decumbens cv. Basilisk under continuous stocking with cattle. Four plant heights were evaluated (10, 20, 30 and 40 cm in the same managed sward, with mean height equal to 25 cm. A randomized blocks design was used, with two replications. Defoliation frequency increased linearly along with plant height in the same pasture. Defoliation intensity, number of defoliations in leaf blade and percentage of leaf blade grazed per tiller also increased linearly along with plant height. The defoliation interval decreased linearly according to plant height. The quadratic model was adequately fitted into grazing efficiency data, reaching the highest value (98% at the sward site with 35 cm plants. The percentage variation in signal grass height showed a negative linear response with initial plant height. The structure of the pasture, characterized by the diversity in plant heights, is simultaneously the cause and consequence of the variability in defoliation patterns in individual tillers, which occur on the horizontal plane of the pasture.  

Net requirements of energy, protein and macrominerals for weight gain of grazing beef cattle castrated at different ages, with and without supplementation

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Anilza Andréia da Rocha

2012-02-01

Full Text Available The objective of this experiment was to estimate the requirements of energy, protein and macrominerals of grazing crossbreds calves, in Brachiaria decumbens Stapf pasture, castrated at different ages, with and without supplementation. Forty-seven young calves at initial age of 120±30.1 days and 115.3±1.97 kg of live weight were used. To estimate net energy requirements for weight gain, a regression equation between energy retained in the gain and empty body weight gain and metabolic empty body weight was obtained. For estimation of net protein requirements for weight gain, a regression equation was adjusted between protein retained in gain and empty body weight gain and energy content of this gain. Net requirements of Ca, P, Mg and Na for weight gain were determined by the equation Y' = a.b. Xb-1, in which a and b represent the intercept and the coefficient of the alometric equation of macromineral body content prediction, respectively. Neither castration nor concentrate supplementation affects body weight gain net requirements, except the ones of Ca, which were higher for non-castrated animals.

Soil attributes of a silvopastoral system in Pernambuco Forest Zone

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Hugo N.B. Lima

2018-01-01

Full Text Available This research evaluated soil properties in a silvopastoral system using double rows of tree legumes. Treatments were signalgrass (Brachiaria decumbens in monoculture or in consortium with sabiá (Mimosa caesalpiniifolia or gliricidia (Gliricidia sepium. Treatments were arranged in a complete randomized block design, with 4 replications. Response variables included chemical characteristics and physical attributes of the soil. Silvopastoral systems had greater (P<0.001 soil exchangeable Ca (gliricidia = 3.2 and sabiá = 3.0 mmolc/dm3 than signalgrass monoculture (2.0 mmolc/dm3. Water infiltration rate was greater within the tree legume double rows (366 mm/h than in signalgrass (162 mm/h (P = 0.02. However, soil moisture was greater in signalgrass pastures (15.9% (P = 0.0020 than in silvopastures (14.9 and 14.8%, where soil moisture levels increased as distance from the tree rows increased. Conversely, the light fraction of soil organic matter was greater within the tree legume double rows than in the grassed area (P = 0.0019. Long-term studies are needed to determine if these benefits accumulate further and the productivity benefits which result.

Influencia de la fertilización, la época y la especie forrajera en la presencia Influence of fertilization, season, and forage species in presence of arbuscular mycorrhizae in a degraded Andisoil of Colombia

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Arnulfo Gómez-Carabalí

2011-01-01

Full Text Available Para determinar la influencia de la fertilización, época, y especies forrajeras en la producción de micorrizas arbusculares se realizó un experimento con una gramínea C4, (Brachiaria dictyoneura), dos leguminosas forrajeras C3 (Arachis pintoi y Centrosema macrocarpum) y la vegetación nativa; cultivadas en dos sistemas de siembra (monocultivo y asociación), dos niveles de fertilización (alto y bajo) y cuatro edades de cosecha. Se uso un diseño de parcelas sub-sub divididas, en el cual la parcela principal fue la especie, los niveles de fertilización como subparcelas y la edad de rebrote como la sub-sub parcela. El número de esporas de hongos micorrízicos en el suelo y el porcentaje de infección en las raíces se incrementó con la edad y varió con la especie y la época del muestreo (seca o húmeda). Se encontraron diferencias en la capacidad para formar simbiosis micorrízica entre las especies de gramíneas y leguminosas bajo condiciones de campo.In the Colombian coffee zone much of the land has infertile soils with an ongoing accelerated degradation. As vegetation has changed from forest to transitory base (cassava cropping) and overgrazed pastures, ground cover has decreased resulting in increasing runoff. These changes have contributed to severe erosion, decline in soil fertility, productivity, soil structure, and water quality as well as loss of biodiversity. A field study was conducted at the farm "La Esperanza" (Mondomo, Department of Cauca, Colombia, South-America). The main objective was to determine the influence of fertilization, season and forage species in Arbuscular Mycorrhyzae in a degraded Andisol. One C4 forage grass (Brachiaria dictyoneura) and two C3 forage legumes (Arachis pintoi and Centrosema macrocarpum) and native vegetation grown under two fertilization levels, cultivated either in monoculture or in association and harvested at four different ages were evaluated. The numbers of mycorrizal spores in the soil

Lixiviação de potássio da palha de espécies de cobertura de solo de acordo com a quantidade de chuva aplicada Potassium leaching from green cover crop residues as affected by rainfall amount

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C. A. Rosolem

2003-04-01

Full Text Available Os restos vegetais deixados na superfície do solo em sistemas de semeadura direta, além de proteger o solo da erosão, constituem considerável reserva de nutrientes que podem ser disponibilizados para a cultura principal, subseqüente. Avaliou-se a lixiviação de K da palha de seis espécies vegetais com potencial de uso como plantas para cobertura do solo de acordo com a quantidade de chuva recebida após o manejo. Milheto (Pennisetum americanum, var. BN-2, sorgo de guiné (Sorghum vulgare, aveia preta (Avena strigosa, triticale (Triticum secale, crotalária juncea (Crotalaria juncea e braquiária (Brachiaria decumbens foram cultivados em vasos com terra, em casa de vegetação, em Botucatu (SP. Aos 45 dias da emergência, as plantas foram cortadas na altura do colo, secas em estufa e submetidas a chuvas simuladas de 4,4, 8,7, 17,4, 34,9 e 69,8 mm, considerando uma quantidade de palha equivalente a 8,0 t ha-1. A máxima retenção de água pela palha corresponde a uma lâmina de até 3,0 mm, independentemente da espécie, praticamente não ocorrendo lixiviação do potássio com chuvas da ordem de 5 mm. A máxima liberação de K por unidade de chuva ocorre com lâminas de até 20 mm, decrescendo a partir deste ponto. A quantidade de K liberado da palha logo após o manejo depende da espécie vegetal, não ultrapassando, no entanto, 24 kg ha-1 com chuvas da ordem de 70 mm, apresentando correlação positiva com a concentração do nutriente no tecido vegetal. O triticale e a aveia são mais eficientes na ciclagem do potássio.Besides protecting soil from erosion, plant residues left on the soil surface by green cover crops in no-till cropping systems represent a considerable nutrient source of nutrients that can be made available for the following crop. Potassium leaching from the straw of six cover crop species was evaluated, in relation to the amount of rain on the residues. Pearl millet (Pennisetum americanum, guinea sorghum (Sorghum

Disponibilidade de macronutrientes em cultivares de cana-de-açúcar submetidas à competição com Brachiaria brizantha Macronutrients availability in sugarcane varieties grown under increasing densities of Brachiaria brizantha

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Leandro Galon

2012-08-01

Full Text Available Objetivou-se com o trabalho verificar os teores foliares dos macronutrientes e o desenvolvimento das cultivares de cana-açúcar 'RB72454', 'RB867515' e 'SP801816' em competição com populações de Brachiaria brizantha. Os tratamentos utilizados foram: 1 cultivar de cana-de-açúcar 'RB72454' e população de B. brizantha de 0, 1, 3, 7, 15, 32, 40, 32, 64, 92, 88 e 112; 2 'RB867515' e 0, 1, 4, 14, 10, 18, 28, 30, 36, 54, 52 e 72; 3 'SP801816' e 0, 1, 3, 6, 14, 20, 24, 26, 26, 32, 46 e 56 plantas m-2. Aos 120 dias após a emergência da cultura, foi quantificada a massa seca (MS da parte aérea da cana-de-açúcar e da B. brizantha. Aos 290 dias após a emergência (DAE, foram coletadas amostras das folhas +3 (terceira folha a partir do ápice das plantas, nas quais foram avaliadas as concentrações de nitrogênio total, fósforo, potássio, magnésio e cálcio. Com o aumento da população de B. brizantha, observou-se redução da MS somente na cultivar 'RB72454'. O aumento na população de B. brizantha reduziu a concentração de fósforo em todas as cultivares, nitrogênio em 'RB72454' e 'SP801816', potássio e magnésio para 'RB72454'. Nas populações mais elevadas de B. brizantha, houve maior competição pelos nutrientes disponíveis no meio, sendo o fósforo o mais limitante. A cultivar 'RB72454' foi a menos competitiva pelos nutrientes no solo. As cultivares apresentaram redução média de 76% na produtividade de colmos na densidade máxima de B. brizantha.This trial aimed to verify foliar levels of macronutrients and development of sugarcane cultivars 'RB72454', 'RB867515' and 'SP801816' under competition with populations of Brachiaria brizantha. The field trial was installed where treatments were: 1 Sugarcane 'RB72454' and B. brizantha population of 0, 1, 3, 7, 15, 32, 40, 32, 64, 92, 88 e 112; 2 'RB867515' e 0, 1, 4, 14, 10, 18, 28, 30, 36, 54, 52 e 72; 3 'SP801816' e 0, 1, 3, 6, 14, 20, 24, 26, 26, 32, 46 e 56 plants m-2. At 120

Change in dry matter and nutritive composition of Brachiaria humidicola grown in Ban Thon soil series

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Jeerasak Chobtang

2008-11-01

Full Text Available This experiment was conducted to determine the change in dry matter and nutritive composition of Humidicola grass (Brachiaria humidicola grown in Ban Thon soil series (infertility soil as a function of growth age. One rai (0.16 ha of two-year-old pasture of fertilised Humidicola grass was uniformly cut and the regrowth samples were collected every twenty days. The samples were subjected to analysis for dry matter content and nutritive composition, i.e. crude protein, ash, calcium, phosphorus, neutral detergent fibre, acid detergent fibre, and acid detergent lignin. The results showed that while the yields of available forage and leaves increased curvilinearly (quadratic, p<0.05, the stem yield increased linearly (p<0.05 over sampling dates. The highest biomass accumulation rate was numerically observed between 40-60 days of regrowth. The concentrations of crude protein, ash, calcium and phosphorus decreased curvilinearly (quadratic, p<0.05 with advancing maturity and reached the lowest flat after 60 days of regrowth. The cell wall components, i.e. NDF, ADF and ADL, increased over the experimental period and reached the highest plateau at 40 days of regrowth. It was concluded that Humidicola grass should be grazed or preserved at the regrowth age of not over 60 days to maximise the utilisation of the grass.

Cyathostomin larvae: presence on Brachiaria humidicola grass during the rainy and dry seasons of Brazil Larvas de ciatostomíneos: disponibilidade em gramínea Brachiaria humidicola nas estações chuvosa e seca do Brasil

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Claudia Navarro dos Santos

2012-03-01

Full Text Available The presence of cyathostomin larvae is directly associated to climatic conditions of each region. This study aimed to evaluate the ecology of infective larvae on Brachiaria humidicola during the dry and rainy seasons from October 2007 to September 2008 in a tropical region, Rio de Janeiro state, southeastern Brazil. Stools were collected from the rectum of horses naturally infected with cyathostomins at the beginning of the rainy season (October to March and dry season (April to September. They were divided into four samples of 500 g and deposited on a grass patch of B. humidicola. Seven days later and every 15 days thereafter samples of feces and grass were collected and processed by the Baermann technique. The mean number of larvae recovered from the grass varied according to the season, with greater recovery of larvae during the peak of the dry season (14,700 L3.kg-¹ DM. There was a statistically significant difference between L3 recovered from feces and grass, but not between L3 recovered from the grass base and apex. These results show that the region’s climate favors the development and survival of infective cyathostomin larvae throughout the year, with a greater number of larvae during the dry season.A disponibilidade de larvas de ciatostomíneos está diretamente relacionada com as condições climáticas de cada região. Para avaliar o comportamento das larvas infectantes nos períodos seco e chuvoso em gramínea Brachiaria humidicola, realizou-se um estudo, no período de outubro/2007 a setembro/2008, na região da Baixada Fluminense, RJ, de clima tropical. Amostras de fezes foram coletadas diretamente do reto de equinos naturalmente infectados por ciatostomíneos, no início do período chuvoso (outubro a março e seco (abril a setembro, divididas em quatro amostras de 500 g e depositadas em um canteiro formado por gramínea B. humidicola. Sete dias após o depósito e, posteriormente, a cada 15 dias, amostras de fezes e gram

Influência do Fósforo, Micorriza e Nitrogênio no Conteúdo de Minerais de Brachiaria brizantha e Arachis pintoi Consorciados Effect of Phosphorus, Mycorrhizal and Nitrogen on Mineral Content of Brachiaria brizantha - Arachis pintoi Mixture

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Ívina Paula Almeida dos Santos

2002-01-01

Full Text Available O experimento foi conduzido em casa de vegetação com o objetivo de avaliar a influência do fósforo (P, fungos micorrízicos arbusculares (FMA's e nitrogênio (N no acúmulo de minerais na MS da parte aérea de braquiária MG-4 (Brachiaria brizantha cv. MG-4 e amendoim forrageiro (Arachis pintoi cv. Amarillo consorciados, em solo de baixa fertilidade. O delineamento utilizado foi o inteiramente casualizado, num esquema fatorial 5x2x2, sendo cinco doses de P (25, 50, 75, 100 e 200 mg de P/kg de solo, dois tratamentos de inoculação do solo (inoculado e não com o FMA Glomus etunicatum e dois tratamentos de N (com e sem N em cobertura, com quatro repetições. Foi realizado o corte da parte aérea das plantas aos 60 dias após a germinação para a determinação das quantidades acumuladas de N, P, K, Ca, Mg e S na MS da parte aérea. As adubações fosfatada e, principalmente, a nitrogenada provocaram aumento no conteúdo de N, P, K, Ca, Mg e S na braquiária MG-4, não se verificando tal aumento com a micorrização. No amendoim forrageiro, observou-se redução destes minerais com a aplicação de N, ao passo que a micorrização resultou em aumento dos mesmos. Por outro lado, a adubação fosfatada provocou pequeno aumento no acúmulo de minerais na MS da parte aérea do amendoim forrageiro.This experiment was carried out in a greenhouse condition to study the effect of phosphorus, arbuscular mycorrhizal fungi and nitrogen on mineral accumulation in braquiaria MG-4 (Brachiaria brizantha cv. MG-4 above ground forage DM and peanut (Arachis pintoi cv. Amarillo mixture, in soil of low fertility. The experimental design was a completely randomized in a 5x2x2 factorial arrangement, with five P rates (25, 50, 75, 100 and 200 mg/kg of soil, two inoculations (inoculated and no inoculated and two levels of N (with and without N, with four replicates. The harvest of the above ground parts of plants was at 60 days after seed germination to determine

INCIDENCE OF Boophilus microplus AND BLOOD PARAMETERS IN CROSSBRED STEERS FED OF SUNFLOWER INCIDÊNCIA DE Boophilus microplus E AVALIAÇÃO DOS PARÂMETROS SANGÜÍNEOS EM BOVINOS MESTIÇOS (HOLANDÊS x ZEBU ALIMENTADOS COM GIRASSOL

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Sérgio Luíz S. Rezende

2007-07-01

Full Text Available This experiment aimed to evaluate the efficacy of sunflower meal and sunflower seeds to control Boophilus microplus in naturally infested steers. The experiment was developed in the Dairy Cattle Facilities of the Veterinary College - UFG. Two herds of steers (Holstein x zebu were allotted in a randomized block design in 2x10 factorial arrangement with six repetitions on Brachiaria decumbens pastures. After 14 days, weekly for two months, B. microplus females > 4 mm were counted, blood samples were collected and the animals were weighed. The B. microplus engorged females were collected to evaluate reproductive parameters. Blood samples were processed to determine: hematocrit, total protein, fibrinogen and leukocytes. The results had been submitted to the analysis of variance and the averages compared for the Scott-Knott test (5%. Tick counts, index (%, larval eclosion, hematocrit, total protein, fibrinogen and leukocytes were similar between treatments. The results do not corroborate the empirical reports concerning the effectiveness of the sunflower to control B. microplus in crossbred steers. KEY-WORDS: Blood values, oily seeds, parasites, tick count. Objetivou-se avaliar a ação do farelo ou das sementes de girassol no controle de Boophilus microplus em novilhos mestiços (holandês x zebu infestados naturalmente. O experimento foi desenvolvido no Setor de Bovinocultura do Departamento de Produção Animal da Escola de Veterinária (EV da UFG. Foram utilizados dois lotes de animais, distribuídos inteiramente ao acaso num fatorial 2 x 10 com seis repetições, em piquetes de Brachiaria decumbens, onde foram suplementados. Após quatorze dias de experimento e a cada sete dias, durante dois meses, num curral de manejo, efetuaram-se a contagem das fêmeas de B. microplus > 4 mm, as coletas de sangue e as pesagens dos bovinos. Colheram-se fêmeas ingurgitadas de B. microplus para avaliação de parâmetros reprodutivos. Amostras de sangue

EFEITOS DOS PERÍODOS DE COMPETIÇÃO DO MATO NA CULTURA DO AMENDOIM: I. SAFRA DA SECA DE 1988

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FRANCISCO SEIITI KASAI

1997-01-01

Full Text Available O presente trabalho foi realizado em 1988, na Estação Experimental de Agronomia da Alta Paulista, em Adamantina, na safra da seca, para estudar o efeito de diferentes períodos de competição do mato no amendoim. Os tratamentos foram vinte, a saber: com e sem presença do mato em todo o ciclo da cultura e, os resultantes da combinação fatorial entre a presença e a ausência de mato no início da cultura e as épocas de remoção da flora infestante - 20, 30, 40, 50, 60, 70, 80, 90 e 100 dias após a semeadura. Cada parcela foi constituída de quatro linhas, com bordadura comum entre as unidades experimentais, perfazendo, com a área útil, 6,0 m2. As espécies da flora infestante que ocorreram com maior freqüência foram Cyperus lanceolatus Poir., Digitaria horizontallis Willd., Brachiaria decumbens Stapf. e Portulaca oleracea L. A convivência do mato com o amendoim diminuiu a produção de vagens e de grãos e a biomassa seca da planta. Não se observou efeito do mato sobre o índice de colheita e o rendimento de grãos em nenhum dos períodos estudados. Uma capina aplicada oito dias ou aos 73 dias após a semeadura, respectivamente, para os tratamentos sem e com mato no início, foi suficiente para a produção de vagens de amendoim estatisticamente igual à obtida quando a cultura foi mantida sem competição durante todo o ciclo.A field experiment was carried out at Adamantina, State of São Paulo, Brazil, to study different periods of weed competition with peanut. The treatments were 20: with and without weed presence through the crop cycle and those resulting from factorial combinations among presence and ausence of weed in the beginning of crop and the time of weed removal - 20, 30, 40, 50, 60, 70, 80, 90 and 100 days after sowing. Each plot was constituted of four lines, with common border among experimental units, with useful area reading 6.0 m2. Weed species, occurring with higher frequencies were Cyperus lanceolatus Poir

Qualidade física de um Latossolo Vermelho em recuperação há dezessete anos Physical quality of oxisol under reclamation for 17 years

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Carolina S. B. Bonini

2012-04-01

Full Text Available Com o objetivo de avaliar a qualidade física de um Latossolo Vermelho em recuperação há 17 anos utilizando-se adubos verdes, gesso e pastagem, foram estudados a densidade do solo e resistência a penetração, como indicadores de sua recuperação. O delineamento experimental foi inteiramente casualizado com nove tratamentos e quatro repetições. Os tratamentos foram: Solo mobilizado; mucuna-preta (MP; guandu (G até 1994, após substituído por feijão-de-porco (FP; calcário + MP; Calcário + G até 1994, após substituído por FP; calcário + gesso + MP; calcário + gesso + G até 1994, após substituído por FP; os tratamentos foram instalados em 1992 e permaneceram por sete anos e em 1999 implantou-se a Brachiaria decumbens; também foram utilizadas duas testemunhas para comparação (vegetação nativa do cerrado e solo exposto. Foram avaliadas densidade do solo, resistência do solo à penetração e umidade do solo. Os resultados foram analisados efetuando-se a análise de variância e teste de Tukey a 5% de probabilidade. Os tratamentos de recuperação do solo estão sendo eficientes na melhoria da sua qualidade e o tratamento com guandu/feijão-de-porco, calcário e gesso, obteve condições físicas semelhantes às do solo de cerrado.The bulk density and resistance to penetration as indicators of recovery were studied with the objective to investigate the physical quality of a Red Latosol (Oxisol under restoration for 17 years using green manures, soil correction, gypsum and pasture. The experimental design was a completely randomized with nine treatments and four replications. The treatments were: control (tilled soil without crop; Stizolobium aterrium; Cajanus cajan until 1994 and then substituted by Canavalia ensiformis; lime+S. aterrimum; lime+C. cajan until 1994 and then substituted by C. ensiformis; lime+gypsum+S. aterrimum; lime+gypsum+C. cajan until 1994 and then substituted by C. ensiformis, the treatments were

Fitomassa e acúmulo de nitrogênio, em espécies vegetais de cobertura do solo para um Latossolo Vermelho distroférrico de Cerrado = Biomass and nitrogen accumulation in cover crops species used in Brazilian Cerrado

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Edicarlos Damacena de Souza

2008-10-01

Full Text Available Espécies vegetais com alta produção de fitomassa são de fundamentalimportância para o desenvolvimento sustentável do plantio direto no cerrado. Objetivou-se avaliar a produção de fitomassa e o acúmulo de nitrogênio em 17 espécies vegetais em um Latossolo Vermelho distroférrico da região do Cerrado. O trabalho foi realizado no campoexperimental da Universidade Federal de Goiás, localizado no Centro de Ciências Agrárias e Biológicas no Campus de Jataí – Estado de Goiás. O delineamento experimental adotado foi o de blocos ao acaso, com cinco repetições. Foram utilizadas as espécies: Aveia pretacomum, Aveia preta IAPAR61, Braquiaria brizantha, Braquiaria decumbens, Capim-pé-degalinha, Milheto BN2, Milheto BRS 1501, Milheto MT, Crotalaria spectabilis, Crotalaria juncea, Guandu normal, Guandu super N, Girassol selvagem, Kenaf 1, Kenaf 2, Nabo forrageiro e Niger. O milheto BRS 1501 obteve a maior fitomassa entre as gramíneas, a C. spectabilis, entre as leguminosas e o nabo forrageiro, entre as outras famílias. O milheto BRS1501, C. spectabilis e nabo forrageiro também obtiveram o maior acúmulo de N na parte aérea. As espécies nabo forrageiro, kenaf 1 e milheto BRS 1501 são as mais recomendadas como cobertura do solo para a região do cerrado goiano.Plant species that have high biomass production are of fundamentalimportance to the sustainable development of no-tillage systems in the cerrado region. This experiment had the objective of evaluating the biomass production and nitrogen accumulation in 17 plant species in a Oxisol of the cerrado region. This experiment was conducted in an experimental field of the Federal University of Goiás, located in the Agricultural and Biological Cientific Center of Jataí - State of Goiás. The experimental layout was a randomized block with 5 replicates. The following species were used: two species of Avena strigosa, Brachiaria brizantha, Brachiaria decumbens, Eleusine indica, three

Eficiência de nova formulação do herbicida oxyfluorfen no controle de plantas daninhas em área de Pinus caribea Morelet var. hondurensis Barr. et Golf Efficiency of new oxyfluorfen formulation to control weeds in area of Pinus caribea Morelet var. hondurensis Barr. et Golf

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Eduardo Antonio Drolhe da Costa

2002-11-01

Full Text Available Foi realizado um experimento para avaliar a seletividade e a eficiência do herbicida oxyfluorfen5 formulado a 480 e 240 g/l, em área com mudas de Pinus caribea Morelet var. hondurensis Barr. et Golf. recém-transplantadas (aplicação em pré-emergência das plantas daninhas e com 12 dias após o transplante (aplicação em pós-emergência inicial das plantas daninhas. O ensaio foi instalado no município de Paulínia, Estado de São Paulo, em um Latossolo Vermelho-Escuro, eutrófico, no ano agrícola 1999/2000. Foi adotado o delineamento em parcelas subsubdivididas no tempo, tendo como tratamento principal, disposto em blocos ao acaso com quatro repetições, o herbicida oxyfluorfen formulado a 480 g/l de ingrediente ativo (i.a., nas doses de 1,0, 1,5 e 2,0 l/ha, e a 240 g/l (i.a., nas doses de 2,0, 3,0 e 4,0 l/ha. Como tratamento secundário (subparcelas considerou-se o modo de aplicação do produto (pré ou pós-emergência das plantas daninhas e como sub-subparcelas, as diferentes épocas de avaliação da eficácia de controle. As mudas foram plantadas no espaçamento de 0,5 x 0,5 m e os tratamentos foram aplicados por meio de um pulverizador costal pressurizado a CO2, a uma pressão de 2,45 kg/cm², utilizando-se um volume de calda igual a 200 l/ha. Os resultados mostraram que o herbicida oxyfluorfen formulado a 480 g/l e 240 g/l mostrou-se eficiente no controle de Brachiaria decumbens, Panicum maximum, Ipomoea grandifolia e Sida rhombifolia em diferentes épocas de avaliação, tanto quando foi aplicado em pré como em pós-emergência, sem ocasionar danos às plantas de Pinus caribea var. hondurensis.A trial was carried out to evaluate Pinus caribea Morelet var. hondurensis Barr. et Golf. selectivity and weed control with oxyfluorfen formulated at 480 (SC and 240 g/l (EC of active ingredient (a.i.. Treatments were sprayed on seedlings at the moment of transplanting and 12 days after. Results showed that oxyfluorfen 480 (SC g/l was

Efeitos de períodos de permanência de clomazone + hexazinona no solo e na palha de cana-de-açúcar antes da ocorrência de chuvas na eficácia de controle de plantas daninhas Effects of different periods of clomazone + hexazinona permanence in soil and sugarcane mulch before the occurrence of rain on weed control efficacy

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C.A. Carbonari

2010-01-01

Full Text Available O presente trabalho teve por objetivo avaliar a eficácia da mistura formulada de clomazone e hexazinona aplicada sobre o solo e em associação com a palha de cana-de-açúcar, após diferentes períodos de permanência sem a ocorrência de chuvas. O experimento foi conduzido em vasos em casa de vegetação, no município de Botucatu-SP. Os vasos foram preenchidos com solo, e as sementes de plantas daninhas (Brachiaria decumbens, Ipomoea grandifolia, Ipomoea hederifolia e Euphorbia heterophylla foram semeadas superficialmente e, em seguida, cobertas ou não com palha de cana-de-açúcar, dependendo do tratamento utilizado. O delineamento experimental utilizado foi o inteiramente casualizado, com quatro repetições. Os tratamentos foram dispostos em um esquema fatorial 3 x 6, sendo os fatores seis períodos sem ocorrência de chuvas (0, 3, 7, 15, 30 e 60 dias e três posicionamentos do produto (sobre o solo sem palha, sobre e sob a palha de cana. Foram realizadas avaliações de controle aos 10, 21, 35 e 42 dias após a ocorrência da chuva. A mistura de clomazone + hexazinona promoveu excelentes resultados de controle para todas as espécies estudadas quando aplicada sobre, sob ou na ausência de palha de cana-de-açúcar. No entanto, observou-se tendência de redução nos níveis de controle para períodos superiores a 60 dias sem ocorrência de chuva.The objective of this work was to evaluate the efficacy of the formulated mixture clomazone and hexazinone applied in soil or combined with sugarcane mulch, after different periods of permanence without the occurrence of rain. The experiment was carried out in vases under greenhouse conditions in Botucatu, São Paulo, Brazil. The weeds Brachiaria decumbens, Ipomoea grandifolia, Ipomoea hederifolia and Euphorbia heterophylla were sown and covered or not with sugarcane mulch. The experiment was arranged in a complete randomized design with four repetitions. The treatments were displaced in a 3x6

Correlación de la productividad de un forraje con las propiedades físicas de un Ultisol en Aquidauana Correlação entre a produtividade de forragem com atributos físicos de um Argissolo em Aquidauana

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Rafael Montanari

2013-02-01

Full Text Available Los sistemas de producción de ganadería y de manejo de pastos alteran las propiedades físicas del suelo, reflejados en la productividad y la composición vegetal. El objetivo de este trabajo fue indicar las propiedades físicas del suelo con mejores correlaciones lineales y espaciales para obtener sitios específicos de manejo del suelo. Se analizaron las correlaciones lineales y espaciales entre la productividad de la materia seca del forraje de Brachiaria decumbens (Stapf y algunas propiedades físicas de un Ultisol en dos profundidades (0,00-0,10 m y 0,10-0,20 m. Para la colecta de los datos fue instalada una red geoestadística con 121 puntos de muestreo. La productividad del forraje varió aleatoriamente y no siguió patrones espaciales, presentando el efecto pepita puro. La resistencia mecánica del suelo a la penetración y la humedad del suelo en la capa de 0,10-0,20 m, son importantes indicadores de la calidad física del suelo. El aumento de estas propiedades en el cultivo del forraje, promovió la reducción de la materia seca del forraje. Por lo tanto, estos indicadores representan confiabilidad para estimar la productividad del forraje.O sistema de produção pecuária e os sistemas de manejo do pasto alteram os atributos físicos do solo, refletindo sobre a produtividade e a composição vegetal. O objetivo deste trabalho foi indicar os atributos do solo com melhores correlações lineares e espaciais para se obter zonas específicas de manejo do solo. Foram analisadas as correlações lineares e espaciais entre a produtividade de matéria seca da forragem de Brachiaria decumbens (Stapf e de alguns atributos físicos de um Argissolo em duas profundidades (0,00-0,10 m e 0,10-0,20 m. Para isso foi instalada uma malha geoestatística para a coleta dos dados contendo 121 pontos de amostragem. A produtividade da forragem variou aleatoriamente e não seguiu padrões espaciais, sendo assim efeito pepita puro. O aumento da resist

GERMINATION AND DEVELOPMENT OF BRACHIARIA SEEDLING IN TEXTURES OF SOIL AND SOWING DEPTH

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J. H. Castaldo

2016-09-01

Full Text Available The agriculture expansion at Brazil is turning to lower clay index soils and consequently, less organic matter content and cation exchange capacity. To overcome those deficiencies, an intense organic matter addition in these soils may be a solution, and this solution is positive when using a crop-livestock integration with corn-pasture dual crop planted on winter. However, to establish this dual-crop system, there is a need to study the behavior of seeds and seedlings of Brachiaria ruziziensis sown in greater depths than normally recommended. Thus, this work aimed to determine the best depth of sowing B. ruziziensis in sandy and loamy soils of Umuarama region, studying the germination and early development of seedlings. The work was held in pots of 12 cm diameter x 12 cm deep, filled with 2 types of soil, a sandy and clay ones with 30 B. ruziziensis seeds sown each pot in five sowing depths: 0, 2, 4, 6 and 8 cm. After 16 days, the number of emerged seedlings was evaluated to set up the germination rate of each treatment, after that, the plants where leveled to 4 each pot, those were cultivated for another 45 days to evaluate the fresh and dried masses of plants and roots, the height of the plants and average length of roots. The sowing depth with higher percentage of germination estimated was 2.65 cm to sandy and 3.02 cm to clay soil. At seedlings development, there was a standard, with better development seedling at lower sowing depths on clay soil and better developments at higher sowing depths in sandy soil.

High degree of genetic diversity among genotypes of the forage grass Brachiaria ruziziensis (Poaceae) detected with ISSR markers.

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Azevedo, A L S; Costa, P P; Machado, M A; de Paula, C M P; Sobrinho, F S

2011-11-17

The grasses of the genus Brachiaria account for 80% of the cultivated pastures in Brazil. Despite its importance for livestock production, little information is available for breeding purposes. Embrapa has a population of B. ruziziensis from different regions of Brazil, representing most of existing variability. This population was used to initiate an improvement program based on recurrent selection. In order to assist the genetic improvement program, we estimated the molecular variability among 93 genotypes of Embrapa's collection using ISSR (inter-simple sequence repeat) markers. DNA was extracted from the leaves. Twelve ISSR primers generated 89 polymorphic bands in the 93 genotypes. The number of bands identified by each primer ranged from two to 13, with a mean of 7.41. Cluster analysis revealed a clearly distinct group, containing most of the B. ruziziensis genotypes apart from the outgroup genotypes. Genetic similarity coefficients ranged from 0.0 to 0.95, with a mean of 0.50 and analysis of molecular variance indicated higher variation within (73.43%) than among species (26.57%). We conclude that there is a high genetic diversity among these B. ruziziensis genotypes, which could be explored by breeding programs.

Capim-braquiária sob lotação contínua e com altura única ou variável durante as estações do ano: morfogênese e dinâmica de tecidos Signalgrass under continuous stocking with fixed or variable height during the seasons: morphogenesis and dynamics of tissues

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Manoel Eduardo Rozalino Santos

2011-11-01

Full Text Available Este trabalho foi realizado com o objetivo de identificar estratégias eficazes de manejo do pastejo de Brachiaria decumbens cv. Basilisk, sob lotação contínua, com base em avaliações das suas características morfogênicas e estruturais. Duas estratégias de manejo do pastejo foram estudadas: em uma, o pasto foi mantido com 25 cm de altura média durante todo o período experimental e, na outra, foi mantido em 15 cm de altura média durante o inverno, com aumento para 25 cm a partir do início da primavera. Adotou-se o delineamento de blocos casualizados em esquema de parcelas subdivididas com quatro repetições. Consideraram-se, como fator primário, as estratégias de manejo do pastejo, caracterizadas pelas alturas médias dos pastos durante as estações do ano (inverno, primavera e verão, e, como fator secundário, as estações. O rebaixamento do pasto para 15 cm no inverno resultou em maior taxa de aparecimento foliar (0,02 folha/perfilho.dia e maior número de folhas vivas (4,5 folhas por perfilho no inverno, mas provocou redução, no inverno, da duração de vida da folha (66 dias, da taxa de senescência foliar (0,22 cm/perfilho.dia e dos comprimentos da lâmina foliar (11 cm e pseudocolmo (15,2 cm em relação ao pasto com 25 cm. Nesta estação, foram menores os valores observados para as taxas de aparecimento foliar (0,06 folha/perfilho.dia, alongamento foliar (0,110 cm/perfilho.dia e alongamento de pseudocolmo (0,008 cm/perfilho.dia, número de folha viva (2,9 folhas por perfilho e comprimentos da lâmina foliar (8,6 cm e do pseudocolmo (13,5 cm. Por outro lado, a duração de vida da folha (139 dias e o número de folhas mortas (2,0 folhas por perfilho foram maiores. O maior valor de taxa de senescência foliar ocorreu na primavera (0,40 cm/perfilho.dia. O pasto de B. decumbens cv. Basilisk sob lotação contínua pode ser manejado de forma sazonal, com rebaixamento para 15 cm no início do inverno e posterior aumento para

Phosphorus, carbon- and nitrogen interactions in productive and degraded tropical pastures

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Oberson, A.; Hegglin, D. D.; Nesper, M.; Rao, I.; Fonte, S.; Ramirez, B.; Velasquez, J.; Tamburini, F.; Bünemann, E. K.; Frossard, E.

2011-12-01

Pastures are the main land use in deforested areas of tropical South America. The highly weathered soils of these regions usually have low total and available phosphorus (P) contents. Low P availability can strongly limit plant and animal productivity and other soil ecosystem functions. Most introduced pastures of Brachiaria spp. are grass-alone (GA) while some are grass-legume (GL) pastures. The majority of the introduced pastures, particularly the grass-alone are at some state of degradation (GD). Pasture degradation induces severe loss of plant biomass production, with drastic ecological and economic implications. Although the importance of P deficiency in pasture degradation has been recognized, the knowledge generated on stoichiometry of carbon (C), nitrogen (N) and P along pathways of the nutrient cycles of pastures, with different botanical composition and productivity, has been very limited. We will present results of a case study realized during 2010 to 2011 in the forest margins agro-ecosystem of the department of Caquetá, Colombia. Our objectives were to determine: i) whether P availability is lower in degraded compared to productive pastures, and ii) whether the introduction of legumes in the pasture increases P availability through enhanced biological P cycling through plant growth, plant litter decomposition and the soil microbial biomass; and iii) whether pasture types (GA vs GL) and the state of pasture degradation affect the C:N:P ratios in nutrient pools of the soil-plant system. An on-farm study was conducted on nine farms in the department of Caquetá, Colombia. On every farm three different pasture types were studied: degraded grass alone pastures (GD), productive grass-alone pastures (GA) and productive grass-legume pastures (GL). Basic soil characteristics and indicators on soil P status, microbial P cycling, plant biomass production, plant litter deposition and nutrient concentrations in plant tissue were determined. Analysis of P, C and N

Brachiaria seeds germination under different concentration of gibberellinGerminação de sementes de braquiária sob diferentes concentrações de giberelina

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Adriano Bortolotti da Silva

2013-05-01

Full Text Available Dormancy in tropical grasses is associated with physiological or physical causes present in freshly harvested seeds. The aim of this study was to evaluate the effect of different concentrations of GA3 in the percentage of germination and suppuration of dormancy of Brachiaria brizantha. Seeds of B. brizantha ‘Marandu’ and ‘MG5’ were immersed in different concentrations of GA3 (0, 25, 50, 75 and 100 mg.L-1 for 2h. After this process, the germination and viability of seed were determinated. The design was completely randomized consisting of 5 treatments with 4 replications for both cultivars. Germination was affected by different concentrations of gibberellins and best results were obtained with the use of 62 and 57 mg.L-1 GA3 for ‘Marandu’ and ‘MG 5’, respectively. A dormência em gramíneas forrageiras está associada às causas fisiológicas ou físicas presentes em sementes recém-colhidas. Este trabalho teve o objetivo de avaliar o efeito de diferentes concentrações de giberelina (GA3 na germinação e superação da dormência das sementes de Brachiaria brizantha. As sementes de B. brizantha ‘Marandu’ e ‘MG 5’ foram imersas nas diferentes concentrações (0, 25, 50, 75 e 100 mg.L-1 do regulador de crescimento GA3 por um período de 2 horas. Após esse processo, foram determinadas a germinação e a viabilidade das sementes. O delineamento foi o inteiramente casualizado, constando de 5 tratamentos com 4 repetições, para ambas as cultivares. A germinação foi afetada pelas diferentes concentrações de giberelinas e os melhores resultados foram obtidos com emprego de 62 e 57 mg.L-1 de GA3, para as cultivares Marandu e MG 5, respectivamente.

Nível de dano econômico de Brachiaria plantaginea na cultura de milho irrigado Economic weed threshold (EWT of Brachiaria plantaginea in irrigated corn crop

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R.A. Vidal

2004-03-01

Full Text Available O nível de dano econômico (NDE consiste na quantidade de plantas daninhas que causa impacto no rendimento de grãos da cultura que justifique o custo de seu controle. Os objetivos deste trabalho foram avaliar a possibilidade de utilizar experimentos de eficácia de herbicidas residuais para determinar o NDE, a partir do rendimento de grãos em relação à densidade de plantas de Brachiaria plantaginea (BRAPL que emergem após o tratamento, e avaliar o impacto do preço da cultura e do custo do controle no NDE. A densidade de BRAPL foi determinada em um experimento no qual se realizaram tratamentos químicos que possibilitaram a emergência de diferentes quantidades de plantas e, em conseqüência, vários níveis de interferência sobre a cultura do milho. A avaliação da densidade foi feita aos 10, 20, 30, 40 e 50 dias após a emergência (DAE, de forma a abranger o período crítico de prevenção da interferência. Ao final do experimento foi avaliado o rendimento de grãos da cultura do milho. A resposta da regressão entre densidade de BRAPL e rendimento de grãos de milho ajustou curvas do tipo exponencial decrescente nas avaliações realizadas aos 10 e 20 DAE e curvas do tipo logístico (sigmoidal aos 30, 40 e 50 DAE. O NDE de BRAPL em milho, com base na densidade determinada no início do período crítico de prevenção da interferência (20 DAE, considerando nível de produtividade de 10 t ha-1, variou entre 0,2 e 2,0 plantas m-2, dependendo do preço do milho e do custo do controle. O NDE determinado ao término do período crítico de interferência (50 DAE correspondeu às densidades de BRAPL de 1,5 a 13 plantas m-2. Conclui-se que o NDE de BRAPL na cultura de milho pode ser estabelecido com dados de densidade desta espécie, determinados em experimentos para testes de herbicidas residuais. Assim, o NDE previsto será adequado para situações em que se deseja decidir por aplicações de herbicidas em pós-emergência em �

Efeito da suplementação sobre a digestibilidade dos nutrientes e desempenho de bezerros lactentes mantidos em pastagens de Brachiaria brizantha = Effect of supplementation on nutrient digestibility and performance of lactating calves fed with Brachiaria brizantha pastures

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Alexandre Amstalden Moraes Sampaio

2010-01-01

Full Text Available Foi avaliado o efeito da suplementação e do tipo do suplemento sobre adigestibilidade dos nutrientes e o desempenho de bezerros Canchim lactentes mantidos em pastagem de Brachiaria brizantha cv. Marandu durante os meses de fevereiro a maio. Os tratamentos foram: sem e com suplementação em creep-feeding com concentrado proteico, comconcentrado energético e com concentrado energético-proteico. Em quadrado latino, foi avaliada a digestibilidade dos nutrientes, utilizando-se quatro bezerros mantidos em baias individuais, recebendo feno da mesma forrageira e com mamadas controladas duas vezes ao dia. O desempenho foi avaliado em delineamento inteiramente casualizado, sendo os 23 bezerros mantidos junto com as matrizes. A suplementação com concentrado energético-proteico determinou melhor ingestão e aproveitamento dos nutrientes (65% de digestibilidade da matéria seca, desempenho dos bezerros (ganhos de peso de 0,98 kg dia-1 e manutenção do peso e das reservas corporais das matrizes. A utilização de suplemento proteico não mostrou bons resultados, sendo estes inferiores inclusive ao desempenho dos bezerros que não receberam suplementação, 0,56 e 0,77 kg dia-1, respectivamente. O desempenho dos bezerros no tratamento sem suplementação foi semelhante àqueles que receberam suplemento energético, porém asmatrizes tiveram redução mais acentuada do peso corporal e das reservas energéticas. A suplementação com concentrado energético-proteico para bezerros lactentes mantidos em pastagens de Brachiaria brizantha cv. Marandu no início da seca mostrou ser uma técnica quebeneficia o desempenho desses animais e das matrizes.This study evaluated the effect of supplementation and the type of supplement on nutrient digestibility and performance of lactating calves fed with Brachiara brizantha cv. Marandu pasture from February to May. The treatments were: supplementation in creep-feeding with protein concentrate, with energy concentrate

Komposisi Kimia, Degradasi Nutrien dan Produksi Gas Metana in Vitro Rumput Tropik yang Diawetkan dengan Metode Silase dan Hay

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B. Santoso

2008-08-01

Full Text Available Six grass species (Pennisetum purpureum, Pennisetum purpureophoides, Sorghum sudanense, Brachiaria brizantha, Imperata cylindrica, and Panicum maximum were harvested at 49 days and preserved as silage or as hay. Samples of silage and hay were evaluated by an in vitro gas production and in vitro nutrient degradability. Total gas production at 24 and 48 h as well as CH4 were higher (P<0.01 in silage than in hay. Brachiaria brizantha had the highest (P<0.01 gas production compared to other species, whereas P. purpureum had the highest CH4 production (mM/g organic matter degraded. Dry matter (DM and organic matter (OM degradations were higher (P<0.01 in silage than hay. When compared with hay, silage had higher (P<0.01 ammonia-N concentration (20.3 vs. 10.6 mg/100 ml and higher (P<0.05 butyric acid concentration (7.9 vs. 7.0 mM. Non-fiber carbohydrate (NFC and crude protein contents were positively correlated with gas production (r = 0.51; P<0.05 and CH4 production (r = 0.64; P<0.01 at 48 h of in vitro incubation. However total gas and CH4 productions were negatively correlated with neutral detergent fiber (NDF content. There were positive correlation between DM (r = 0.90; P<0.01, OM (r = 0.93; P<0.01, and NDF (r = 0.84; P<0.01 degradations and gas production.

RESPOSTA DE DUAS CULTIVARES DE ARROZ DE TERRAS ALTAS EM CONVIVÊNCIA COM Brachiaria brizantha

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Abdias Alves De Oliveira

2009-01-01

Full Text Available The objective of this work was to evaluate to the sowing time of the Brachiaria brizantha forage intercrop with two upland rice cultivars on the agronomics characteristics of both species. It was used randomized blocks in experimental design arranged in factorial scheme 2x2+4, with four replicates. The first factor was constituted by the upland rice cultivars (BRS Primavera e BRSMG Curinga and the second factor by two sowing times of B. brizantha forage (simultaneous sowing between rice and forage and sowing of the forage in the flowering of the rice. The additional treatments consisted of the sole crops upland rice cultivars and B. brizantha forage for each sowing time. In rice was evaluated the height of the plants, bedding, difficulty of the harvest, the number of panicles per area, grain per panicles, percentage of full and empty grains, 100-grain mass and grain yield. In the B. brizantha forage was evaluated the height of the tillers, the total dry mass and the rate of cultural growth. It was observed that the B. brizantha forage interfered in the productivity components of both upland rice cultivars and difficult significantly the harvest of the rice. The upland rice cultivars showed small competitive capacity with the B. brizantha forage when the establishment of the forage occurred simultaneously to the rice. However, to the measure that the sowing was occurred with the established rice already, the B. brizantha forage had his growth suppressed.

Produção e composição química da Brachiaria brizantha cv. MG-4 sob efeito de adubação com NPK = Yield and chemical composition of Brachiaria brizantha cv. MG-4 under the effect of NPK fertilization

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Thaisa Grazielle Radin Magalhães Teles

2011-04-01

Full Text Available O objetivo deste trabalho foi avaliar os efeitos de combinações de doses de nitrogênio, fósforo e potássio sobre a produção de matéria seca e composição química de Brachiaria brizantha cv. MG-4. O experimento foi composto por 16 tratamentos de NPK, conforme matriz experimental Plan Puebla II, distribuídos em delineamento inteiramentecasualizado com cinco repetições. Utilizou-se um Argissolo Vermelho-Amarelo Distrófico Arênico e, como fonte de N, P e K, foram utilizados sulfato de amônio e uréia, superfosfato triplo e cloreto de potássio, respectivamente. O material coletado foi separado em colmo e folha, e pré-seco para a determinação da produção matéria seca de folhas (MSF, colmos (MSC e total (MST, teor de proteína bruta (PB, N, P e K. A adubação promoveu incremento na produção da B. brizantha cv. MG-4, cujas doses de 360-370-360 g vaso-1 de NPK, respectivamente, proporcionaram 95% da maior produção de MST observada. As produtividades máximas foram nas doses de 373, 407 e 317 mg dm-3 de N de solo para MST, MSF e MSC, respectivamente. As doses de N proporcionaram incrementos nos teores de PB das folhas. As adubações fosfatada e nitrogenada proporcionaram aumento na quantidade acumulada de N, P e K na B. brizantha cv. MG-4.The objective of this work was to evaluate the effects of combinations of nitrogen (N, phosphorus (P and potassium (K on the dry matter yield and chemical composition of Brachiaria brizantha cv. MG-4. The experiment consisted of 16 combination levels of NPK, according to experimental matrix Plan Puebla II, in a completely randomized design with five replications. It used a dystrophic RedYellow Sand-Argisol; ammonium and urea sulfate, triple super phosphate and potassium chloride were used as sources of N, P and K, respectively. The harvested material was separated into leaves and stem and submitted to dry matter yield (DMY evaluations of the aerial part, crude protein (CP and determination of

Ingestive behavior of cattle kept in Brachiaria brizantha cv. Xaraés grass managed under different grazing heights

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Marco Aurélio Alves de Freitas Barbosa

2014-02-01

Full Text Available This experiment was conducted to evaluate the effect of grazing heights on daytime behavioral activities of Nellore beef cattle in the rainy season. The experimental area was 12 hectares divided into paddocks of one hectare each. The treatments consisted of four defoliation heights (15, 30, 45 and 60 cm in pastures of Brachiaria brizantha cv. Xaraés with three replicates each. It was used the continuos grazing method, with variable stocking rate. Forage samples collected on the plots were sent to the laboratory for separation of the botanical components, weighing and determination of dry matter, with the material collected by simulated grazing. The variables: grazing time, idle time and ruminating time were evaluated for 12 consecutive hours on days 15 and 16 February 2011, considering the morning and afternoon periods. It was used a completely randomized design. The height of the canopy significantly influenced the daily grazing time and ruminating time, with a quadratic response as a function of time of defoliation. The bite rate decreased as a function of heights studied. However the chemical composition of the material collected by simulated grazing did not differ between treatments. Xaraés grass swards grazed at around 45 cm height provide greater ease of apprehension by grazing cattle.

Replacement of soybean meal by soybean in multiple supplements for beef heifers grazing Urochloa decumbens during the dry season

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Daniel Mageste de Almeida

2015-12-01

Full Text Available This study aimed to evaluate the effect of replacing soybean meal with soybean in multiple supplements on nutritional parameters, microbial efficiency and productive and reproductive performance of heifers grazing in Urochloa decumbens during the drought period. Were used 39 crossbred heifers of initial age and initial weight of 21 months and 309.5±7 kg, respectively. The experimental design was completely randomized with four treatments with eight replicates, and a control treatment with seven replications. Two treatments had soybean meal as the protein source and two treatments had soybean as the protein source, containing 25% and 40% crude protein. The amount of supplement offered was 1.0 kg/animal/day. The animals of the control group received only mineral salt ad libitum. The supplemented animals had higher average daily gain (ADG than control animals (P<0.10, and there was no difference in ADG among the supplements (P>0.10. There was an effect of supplementation (P <0.10 on intake of dry matter (DM, organic matter (OM, crude protein (CP, ether extract (EE, non-fiber carbohydrates (NFC, total digestible nutrients (TDN and neutral detergent fiber corrected for ash and protein (NDF. There were no differences (P>0.10 on intake of OM and DM grazing between the supplemented and non-supplemented. Supplementation improved DM digestibility and all constituents of the diet (P<0.10. It was found that the provision of multiple supplements optimizes the performance of heifers grazing during the dry season, and that the substitution of soybean meal by soybean did not improve productive performance of animals.

Dynamics, production and quality of “Brachiaria brizantha” subjected to water diet and nitrogen fertilization Dinâmica, produção e qualidade da "Brachiaria brizantha" submetida a regime hídrico e adubação nitrogenada1

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Daniela Deitos Fries

2011-03-01

Full Text Available The experiment was conducted in vegetation house of the area of Forragicultura and Pasture of the State University of Southwest Bahia, from January to June 2009. The treatments were 4 diet water (20, 40, 60 and 80% of field capacity and 2 nitrogen levels (0 and 150kg N/ha with four replications. We used a completely randomized design in a factorial 4 x 2. The studied morphogenical characteristics were: leaf appearance rate, leaf elongation rate, phyllochron, leaf life span and rate of stem elongation; and the structural were: final leaf length, total number of leaves, number of leaves in senescence, number of dead leaves, maximum height of plant, number of tillers per plant and number of tillers per pot than the dry matter production of shoots and roots as well as the chemical components of air stop. The results had demonstrated that the interaction between diet water x doses of nitrogen was significant for the productions of natural matter, dry matter of the aerial part and roots. The results had evidenced that the practical of the nitrogen fertilization and the irrigation contributes positively in the forage production and development of the Brachiaria brizantha cv. MG-5.O experimento foi conduzido em casa de vegetação da Universidade Estadual do Sudoeste da Bahia, de janeiro a junho de 2009. Os tratamentos utilizados foram quatro regimes hídricos (20, 40, 60 e 80% da capacidade de campo e duas doses de nitrogênio (0 e 150kg de N/ha com quatro repetições. O delineamento utilizado foi o inteiramente casualizado, em esquema fatorial 4 x 2. As características morfogênicas avaliadas foram: taxa de aparecimento foliar, taxa de alongamento foliar, filocrono, duração de vida da folha e taxa de alongamento do colmo; e as estruturais: comprimento final da folha, número total de folhas, número de folhas em senescência, número de folhas mortas, altura máxima da planta, número de perfilhos por planta e número de perfilhos por vaso, al

Methods to quantify the impacts of water erosion on productivity of tropical soils

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Obando, Franco H

2000-01-01

A review on methods to quantify the impacts of water erosion on soil properties and crop yield is presented. On the basis of results of soil losses through plastic shading meshes on oxisols in the eastern plains of Colombia, the experimental design to quantify erosion induced losses in soil productivity suggested by Stocking (1985) for tropical soils is modified. With the purpose of producing contrasting levels of natural erosion, simple 33% and 45% shading rates meshes, and superposed 33% and 45% meshes were used. These were stretched out on stocking 5 m x 10 m run-off plots at 40 cm height from soil surface. Annual soil losses produced under the above mentioned shading meshes treatments did not present significant differences. It was demonstrated that 33%, 45% as well as superposed 33% and 45% produce an equivalent surface cover, CVE, greater than 90% comparable to that produced by zero grazing Brachiaria decumbens pasture. Such results allowed presenting modifications to the stocking design. It is recommended to use alternated stripes of bare soil and shading meshes of different width to produce contrasting levels of equivalent soil surface cover and consequently contrasting erosion rates. Design of the modified stocking run-off plots, including collecting channels, collecting tanks and a Geib multibox divisor are presented

Occurrence of adults and biological aspects of Geniates borelli Camerano (Coleoptera, Scarabaeidae, Rutelinae in Aquidauana, MS, Brazil

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Sergio Roberto Rodrigues

2012-09-01

Full Text Available Occurrence of adults and biological aspects of Geniates borelli Camerano (Coleoptera, Scarabaeidae, Rutelinae in Aquidauana, Mato Grosso do Sul, Brazil. Due to the importance of Geniates borelli Camerano as a pest in many crops, studies were developed at Universidade Estadual de Mato Grosso do Sul, Aquidauana campus, MS, Brazil. Adults were collected with a light trap from January 2006 to December 2007. 3,320 adults were collected, and the highest quantities were obtained in October 2006 and November 2007, with 1,548 and 802 adults recorded, respectively. Collected adults were kept in plastic containers with soil and Brachiaria decumbens seedlings for oviposition. 535 eggs measuring 2.30 × 1.60 mm were obtained. As the embryonic development progressed, eggs increased in size to 3.00 × 2.70 mm, and this change occurred between 6 and 10 days after oviposition. The embryonic period lasted 17.9 days. The first, second, and third instars lasted 37.6, 49.7, and 74 days, respectively. The prepupal stage lasted 65.9 days and the pupal stage lasted an average of 18.5 days. The biological cycle is completed in 315.8 days, which characterizes the species as univoltine. The average longevity of females was 35.4 days and 28.5 days for males.

Sowing depths of brachiaria in intercropping with corn in no tillage planting Profundidade de semeadura de braquiárias em consorciação com milho em plantio direto

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Rodolfo de N. Gazola

2013-02-01

Full Text Available The forage production in crop-livestock integration is critical both for formation of straw for no tillage planting and food for livestock farm. The experiment was conducted in the autumn/winter of 2009 and 2010, in the city of Selvíria -state of Mato Grosso do Sul -MS, Brazil, at Experimental Station of FEIS/UNESP. The objective was to evaluate the optimal depth for deposition of seeds of two Brachiaria species intercropped with corn with emphasis on grain yield and straw. The experimental design was a randomized block design in a factorial scheme 3 x 3, with four replications. The main treatments were two species of Brachiaria (Urochloa brizantha "Marandú" and Urochloa ruziziensis, which seeds were mixed with corn fertilizer and a control treatment (without intercropping. Secondary treatments consisted of three depths (8; 10 and 16 cm in the deposition of fertilizer (in the consortium and the control treatments. The intercropping corn with Brachiaria produced similar amounts of straw. The straw total production was higher when intercropped and decreased with depth. The consortium with U. ruziziensis provided higher grain yield of corn in relation to U. brizantha, in 2010. The sowing depth of forages did not affect corn yield.A produção de forragem na integração lavoura-pecuária é de suma importância, tanto para alimentação animal como para formação de palhada para plantio direto. O experimento foi conduzido no outono/inverno de 2009 e 2010, em Selvíria -MS, na Fazenda de Ensino, Pesquisa e Extensão da FEIS/UNESP. O objetivo foi avaliar a profundidade mais adequada para deposição das sementes de duas espécies de braquiárias em consórcio com milho, com ênfase para a produtividade do milho e formação de palha. O delineamento experimental foi em blocos ao acaso, em esquema fatorial 3 x 3, com quatro repetições. Os tratamentos principais foram duas espécies de braquiárias (Urochloa brizantha cv. Marandú e Urochloa

Priming and stress under high humidity and temperature on the physiological quality of Brachiaria brizantha cv. MG-5 seeds

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Thiago Barbosa Batista

2016-01-01

Full Text Available Palisade grass is a forage plant that is widely used in pasture cropping in the Brazilian savannah. The aim of this experiment was to evaluate palisade grass (Brachiaria brizantha cv. MG–5 seeds subjected to priming and stress at high humidity and temperature (before and after conditioning. The experimental design was completely randomized in a 2x5 factorial arrangement. Seeds were exposed to stress under high humidity and temperature (before and after conditioning and five priming treatments [Water (Control, potassium nitrate (KNO3 at 0.2%, calcium nitrate Ca(NO32 at 0.2%, gibberellin (GA3 at 0.2% and glucose at 10%] with four replications. Two experiments were performed: Experiment I - seed with chemical scarification using H2SO4 and Experiment II - without scarification. The stress on the seed was applied using artificial aging at 41°C for 96 hours. Seed priming was accomplished by immersion at 25°C for 2 hours. Thereafter, the seeds were oven-dried at 35°C until they regained hygroscopic equilibrium. Seed germination and vigor were evaluated. Priming using KNO3 and Ca(NO32 produced seeds with high tolerance to stress under high temperature, and this process is efficient to overcome dormancy.

Processamento da casca de mandioca na alimentação de ovinos: desempenho, características de carcaça, morfologia ruminal e eficiência econômica Processing of cassava peel in sheep feeding: performance, carcass characteristics, ruminal morphology and economic efficiency

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Peter Bitencourt Faria

2011-12-01

Full Text Available Avaliou-se o efeito de diferentes formas de processamento da casca de mandioca na alimentação sobre o desempenho e as características de carcaça, a morfologia ruminal e a viabilidade técnico-econômica da criação de ovinos. Foram utilizados 20 ovinos machos da raça Santa Inês, desmamados, com peso inicial de 19,02±0,21 kg e 90 dias de vida. O delineamento experimental foi inteiramente casualizado com cinco repetições por dieta. Durante o período experimental de 84 dias, incluindo 14 dias de adaptação, os animais foram mantidos em sistema de semiconfinamento em pastagem de Brachiaria decumbens. Foram avaliadas quatro formas de processamento da casca de mandioca: desidratada triturada em peneira de 12 ou de 5 mm; úmida triturada e ensilada; e úmida triturada e hidrolisada com 0,5% de cal virgem (óxido de cálcio - CaO. O peso médio ao abate foi 30,72±1,46 kg. Não houve influência do tipo de processamento da casca sobre as características de desempenho analisadas, as características quantitativas de carcaça e a morfologia ruminal, sendo influenciado somente o rendimento de paleta. A casca de mandioca hidrolisada foi a que promoveu melhor eficiência econômica. Os tipos de processamento da casca de mandioca não alteram o desempenho, as características de carcaça, os rendimentos de corte e a morfologia ruminal dos ovinos Santa Inês.The objective of this trial was to evaluate the effect of different forms of processing of cassava peel in sheep feeding on performance traits, carcass, morphology and rumen and economic technical feasibility. Twenty non-castrated male Santa Ines lambs of 19.02±0.21 kg of initial body weight and 90 days of age at the beginning of the study were used in this trial. The design was completely randomized design with five replications per treatment. During the experimental period of 84 days, including 14 days of adaptation, animals were kept in semi-confinement on Brachiaria decumbens. Four forms

Adubação nitrogenada do arroz de terras altas no Sistema Plantio Direto Nitrogen fertilization of upland rice under no-tillage system

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Cleber M. Guimarães

2003-08-01

Full Text Available Este trabalho objetivou determinar a dose e o modo de aplicação de nitrogênio (N mais adequados para o arroz cultivado após pastagem ou soja, sob Sistema Plantio Direto (SPD. Os experimentos foram conduzidos em 1999/2000, em Santo Antônio de Goiás, GO, depois da pastagem de Brachiaria decumbens, e em Campo Verde, MT, após soja. Foi utilizado o delineamento de blocos casualizados, em esquema fatorial 5 x 3. Os tratamentos consistiram de cinco doses de N (12 ou 7, 40, 80, 120 e 160 kg ha-1 combinadas com três modos de aplicação: totalmente na semeadura, metade na semeadura e metade na cobertura, e dois terços na semeadura e um terço na cobertura. A dose de 12 kg de N ha-1 foi aplicada no experimento após pastagem que a de 7 kg de N ha-1, em seguida à soja. O arroz apresentou maior resposta à adubação nitrogenada após pastagem e depois de soja. A resposta da produtividade do arroz ao N após pastagem, dependeu do modo de aplicação deste nutriente, sendo 100 kg ha-1 a dose econômica de N para a aplicação total na semeadura. Em seguida à soja, o modo de aplicação não afetou a produtividade do arroz, sendo 68 kg ha-1 a dose econômica de N.The objective of this work was to determine the most adequate nitrogen (N dose and the mode of its application for the upland rice grown after pasture or soybean, under no-tillage. The experiments were carried out during the 1999/2000 growing season, in Santo Antônio de Goiás, GO, after Brachiaria decumbens pasture, and in Campo Verde, MT, after soybean. A completely randomized block design was used, in a 5 x 3 factorial scheme. The treatments consisted of five doses of N (12 or 7, 40, 80, 120, and 160 kg ha-1 combined with three modes of application: total at sowing, half at sowing and half top dressing, and two third at sowing and one third top dressing. N dose of 12 kg ha-1 was applied in the first experiment and N dose of 7 kg ha-1 in the second one. Rice showed higher response to N

Levels of mineral mixture and urea in supplementation of crossbred heifers, with Gyr predominance, reared at pasture during the dry season Níveis de mistura mineral e ureia na suplementação de dietas para novilhas mestiças, com predominância de Gir, recriadas a pasto durante o período da seca

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Bruno Pietsch Cunha Mendonça

2010-10-01

Full Text Available It was evaluated several levels of mineral mixture and urea for crossbred heifers, with Gyr predominance, in the dry season period in Zona da Mata region in Minas Gerais. The experiment was carried out in a Brachiaria decumbens pasture area, divided in five paddocks of 3.5 hectares. It was used 35 heifers distributed in a 2 õ 2 + 1 factorial scheme, composed of two levels of urea (10 and 25%, two levels of mineral salt (10 and 25% and a control diet (only mineral salt, totaling five diets, each one evaluated with seven replicates. The supplements were based on ground corn, urea, ammonia sulfate and mineral mixture with 32 to 72% crude protein, and they composed the following diets: MM ( mineral mix, 10:10 (10% mineral mix, 10% urea and 80% corn; 10:25 (10% mineral mix, 25% urea and 65% corn; 25:10 (25% mineral mix, 10% urea and 65% corn, and 25:25 (25% mineral mix, 25% urea and 50% corn. Urea and mineral salt are effective in controlling supplement intake by bovines growing on pastures during dry season because the higher their levels, the lower the intake of supplements. Diets with 25% urea and 10% mineral salt provided higher daily weight gain and higher weight gain:supplemment intake ratio.Avaliaram-se diversos níveis de mistura mineral e ureia para novilhas mestiças, com predominância de Gir, no período da seca na região da Zona da Mata de Minas Gerais. O experimento foi realizado em uma área de pastagem formada de Brachiaria decumbens, dividida em cinco piquetes de 3,5 ha. Utilizaram-se 35 novilhas distribuídas em um esquema fatorial tipo 2 õ 2 + 1, composto de dois níveis de ureia (10 e 25%, dois níveis de sal mineral (10 e 25% e uma dieta controle (somente sal mineral, totalizando cinco dietas, cada uma avaliada com sete repetições. Os suplementos foram à base de milho moído, ureia, sulfato de amônia e mistura mineral, com 32 a 72% de proteína bruta, e compuseram as seguintes dietas: MM (mistura mineral; 10:10 (10% de

Efeito residual de herbicidas aplicados em pré-emergência em diferentes solos Residual effect of herbicides applied in pre-emergence in different soils

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M.H. Inoue

2011-06-01

Full Text Available O objetivo deste trabalho foi monitorar o efeito residual dos herbicidas ametryne, clomazone e diuron, aplicados em pré-emergência, utilizando amostras de um Neossolo Quartzarênico e de um Latossolo Vermelho, com texturas e composições contrastantes. Para isso, foram conduzidos seis bioensaios em casa de vegetação, com amostras de um Neossolo Quartzarênico (textura arenosa e de um Latossolo Vermelho (textura argilosa. Foi avaliado o efeito residual de ametryne (0, 1,60 e 2,40 kg ha-1, clomazone (0, 0,90 e 1,10 kg ha-1 e diuron (0, 1,60 e 3,20 kg ha-1, por meio de semeadura de bioindicador previamente selecionado (Cucumis sativus ou Brachiaria decumbens aos 0, 25, 50, 75 e 100 dias após a aplicação (DAA. Verificou-se que ametryne proporcionou 80% de controle até os 40 DAA, independentemente do solo e da dose. O clomazone apresentou efeito residual satisfatório quando aplicado na dose recomendada em solo argiloso, mantendo o controle acima de 80% até os 71 DAA. Em solo arenoso, o controle não foi satisfatório já aos 25 DAA, mesmo na dose recomendada para solo argiloso. Diuron apresentou alta estabilidade em solo argiloso, observando-se controle superior a 91% até os 100 DAA na dose recomendada e controle acima de 80% até os 54 DAA na dose recomendada para solo arenoso. No entanto, em solo arenoso não houve aumento do efeito residual, mesmo com a aplicação da dose recomendada para solo argiloso.The objective of this work was to monitor the residual effect of the herbicides ametryne, clomazone and diuron, applied in pre-emergence, using Psament and Red Latosol with contrasting texture and composition. Thus, six experiments were conducted under greenhouse conditions with samples of Psament (sandy texture and Red Latosol (clay texture. The residual effect of ametryne (0, 1.60 and 2.40 kg ha-1, clomazone (0, 0.90 and 1.10 kg ha-1 and diuron (0, 1.60 and 3.20 kg ha 1 was evaluated by sowing the test plant (Cucumis sativus or

Profundidade de semeadura e crescimento inicial de espécies forrageiras utilizadas para cobertura do solo Depth of sowing and initial growth of forage species used for soil coverage

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Leandro Pereira Pacheco

2010-10-01

Full Text Available O uso do consórcio entre plantas de cobertura e culturas anuais, no Cerrado, tem sido prática cada vez mais difundida, pela possibilidade de implantação das forrageiras durante o desenvolvimento das culturas anuais, através da diferença de profundidade e sistema de semeadura. Objetivou-se, neste trabalho avaliar a emergência e algumas características agronômicas de quatro espécies de plantas de cobertura, em diferentes profundidades, visando ao seu emprego na consorciação e sobressemeadura em culturas anuais. O experimento foi conduzido em casa-de-vegetação, no delineamento experimental de blocos ao acaso, em arranjo fatorial 4 x 7, composto pelas plantas de cobertura Brachiaria brizantha, B. decumbens, B. ruziziensis e Panicum maximum cv. Tanzânia, e por seis profundidades de semeadura e um sistema de cobertura de sementes (0 sem cobertura, 0 com cobertura, 1, 4, 8, 10 e 15 cm. As sementes foram semeadas em vasos e as plantas cultivadas por 40 dias. Avaliou-se o índice e o tempo de emergência, a altura de plantas, a fitomassa verde e seca da parte aérea, a área foliar, a fitomassa seca radicular e a densidade de comprimento radicular. O maior desenvolvimento das plantas estudadas foi detectado nas semeaduras até 1 cm de profundidade. O P. maximum não apresentou aptidão para uso em consórcio com culturas anuais.Não se recomenda a semeadura das plantas de cobertura a partir de 10 cm.The use of the consortium between cover crops and annual crops in the Cerrado, is an increasingly widespread practice, because of the possibility of deployment of cover crops during the development of annual crops by the difference in depth and seeding system. The objective was to evaluate the emergency and some agronomic characteristics of four species of cover crops at different seeding depths, to use them in consortium and oversown in annual crops. The experiment was conducted in a greenhouse, and the experimental design of randomized blocks

Occurrence of adults and biological aspects of Geniates borelli Camerano (Coleoptera, Scarabaeidae, Rutelinae in Aquidauana, MS, Brazil Ocorrência de adultos e aspectos biológicos de Geniates borelli Camerano (Coloptera, Scarabaeidae, Rutelinae em Aquidauana, Mato Grosso do Sul, Brasil

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Sergio Roberto Rodrigues

2012-09-01

Full Text Available Occurrence of adults and biological aspects of Geniates borelli Camerano (Coleoptera, Scarabaeidae, Rutelinae in Aquidauana, Mato Grosso do Sul, Brazil. Due to the importance of Geniates borelli Camerano as a pest in many crops, studies were developed at Universidade Estadual de Mato Grosso do Sul, Aquidauana campus, MS, Brazil. Adults were collected with a light trap from January 2006 to December 2007. 3,320 adults were collected, and the highest quantities were obtained in October 2006 and November 2007, with 1,548 and 802 adults recorded, respectively. Collected adults were kept in plastic containers with soil and Brachiaria decumbens seedlings for oviposition. 535 eggs measuring 2.30 × 1.60 mm were obtained. As the embryonic development progressed, eggs increased in size to 3.00 × 2.70 mm, and this change occurred between 6 and 10 days after oviposition. The embryonic period lasted 17.9 days. The first, second, and third instars lasted 37.6, 49.7, and 74 days, respectively. The prepupal stage lasted 65.9 days and the pupal stage lasted an average of 18.5 days. The biological cycle is completed in 315.8 days, which characterizes the species as univoltine. The average longevity of females was 35.4 days and 28.5 days for males.Ocorrência de adultos e aspectos biológicos de Geniates borelli Camerano (Coloptera, Scarabaeidae, Rutelinae em Aquidauana, Mato Grosso do Sul, Brasil. Devido a importância de Geniates borelli Camerano como praga de culturas, foram desenvolvidos estudos na Universidade Estadual de Mato Grosso do Sul, no campus de Aquidauana, MS. Com o uso de armadilha luminosa realizou-se a coleta de adultos de janeiro de 2006 a dezembro de 2007. Foram coletados 3.320 adultos, e as maiores quantidades foram obtidas em outubro de 2006 e novembro de 2007, onde se registraram, respectivamente 1.548 e 802 adultos. Os adultos coletados foram mantidos em recipientes de plástico, contendo solo e mudas de Brachiaria decumbens, para que

Evaluation of dairy cows intake behavior grazing Brachiaria brizantha fed different levels of concentrate at diet

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Fabrício Bacelar Lima Mendes

2013-12-01

Full Text Available The objective with this research was to evaluate the dairy cows intake behavior grazing Brachiaria brizantha submitted to different levels of concentrate supplementation in the diet. Used 16 lactating cows ½ Holstein x ½ Zebu, with an average of 80 ±10.14 days of lactation and body weight of 454.7 ± 54.51 kg. The animals were distributed in four treatments, using a 4x4 Latin square. The evaluation of behavior was done every ten minutes, during 24 hours on the 16th day of period. We used analysis of variance and regression probability of 0.05. The time spent grazing, ruminating and other activities, the numbers of grazing, ruminating, of bites per day and chews per cake, the grazing times, total power and total chewing, bit rate, time to swallow; time per bolus ruminated; chewing speed and power efficiency for NDF were not altered by increased levels of concentrate. The time of trough, the trough period, the bit size, the chews time for bolus, feeding efficiency for DM, NFC, and TDN and rumination efficiency linearly increased. Periods of rumination, deglutition bits, number of rumination chews per day, decreased linearly with increasing levels of concentrate. Significant quadratic effect of concentrate level on the number of periods in other activities and over time on other activities. Supplementation with 33.8% concentrate in the diet of cows grazing not promote changes in the activity of grazing, ruminating and other activities, but increases the time of trough. The increase in concentrate diet improves the efficiencies of feeding and rumination

Evaluación del establecimiento de una colección de accesiones de Brachiaria brizantha asociadas con Stylosanthes guianensis CIAT-184 Evaluation of the establishment of a collection of Brachiaria brizantha accessions associated to Stylosanthes guianensis CIAT-184

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Yuseika Olivera

2012-06-01

Full Text Available En un suelo ácido (pH ~ 4,9, de baja fertilidad, se estudió una colección de 20 accesiones de Brachiaria brizantha asociadas a Stylosanthes guianensis CIAT-184, con el objetivo de evaluar su comportamiento agronómico durante la etapa de establecimiento. Se utilizaron parcelas de 5 x 4 m, con tres réplicas. Los indicadores medidos y/o estimados fueron: el porcentaje de supervivencia (15, 30 y 45 días, la altura de la planta, la abundancia de hojas, el vigor, las afectaciones provocadas por las plagas y la infestación por enfermedades. Para la interpretación de los resultados se utilizó el análisis de componentes principales. En los primeros 45 días las accesiones CIAT-16317, CIAT-26032, CIAT-16485 y el cv. Mulato alcanzaron los mejores índices de supervivencia (por encima del 90%. Después de los 45 días se detectó una alta variabilidad (90,30% para las dos primeras componentes. Al agrupar las accesiones se identificó la formación de siete grupos, en algunos de los cuales predominaron individuos de porte alto, y en otros, plantas con buen vigor y hojosidad. De manera general, se puede concluir que hubo un comportamiento aceptable de la asociación entre las accesiones de B. brizantha y S. guianensis CIAT-184, ya que todas en mayor o menor medida cumplimentaron la etapa de establecimiento. Se destacaron las accesiones de los grupos IV, V y VII, ya que mostraron resultados positivos (por encima de la media en dos indicadores de los tres estimados. Se recomienda dar continuidad a la evaluación de la fase de explotación de este germoplasma con animales, de manera tal que sea posible, en el futuro mediato, seleccionar las accesiones más sobresalientes durante todo el periodo experimental.On a low-fertility, acid soil (pH ~ 4,9, a collection of 20 Brachiaria brizantha accessions associated to Stylosanthes guianensis CIAT-184 was studied, in order to evaluate its agronomic performance during the establishment stage. For such purpose

In vitro assay for the anti-Brucella activity of medicinal plants against tetracycline-resistant Brucella melitensis.

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Motamedi, Hossein; Darabpour, Esmaeil; Gholipour, Mahnaz; Seyyed Nejad, Seyyed Mansour

2010-07-01

Brucellosis, a zoonosis caused by four species of brucella, has a high morbidity. Brucella melitensis is the main causative agent of brucellosis in both human and small ruminants. As an alternative to conventional antibiotics, medicinal plants are valuable resources for new agents against antibiotic-resistant strains. The aim of this study was to investigate the usage of native plants for brucellosis treatment. For this purpose, the anti-brucella activities of ethanolic and methanolic extracts of Salvia sclarea, Oliveria decumbens, Ferulago angulata, Vitex pseudo-negundo, Teucrium polium, Plantago ovata, Cordia myxa, and Crocus sativus were assessed. The activity against a resistant Br. melitensis strain was determined by disc diffusion method at various concentrations from 50-400 mg/ml. Antibiotic discs were also used as a control. Among the evaluated herbs, six plant (Salvia sclarea, Oliveria decumbens, Ferulago angulata, Vitex pseudo-negundo, Teucrium polium, and Crocus sativus) showed anti-brucella activity. Oliveria decumbens was chosen as the most effective plant for further studies. A tested isolate exhibited resistance to tetracycline, nafcillin, oxacillin, methicillin, and colistin. Minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values for Oliveria decumbens against resistant Br. melitensis were the same (5 mg/ml), and for gentamicin they were both 2 mg/ml. Time-kill kinetics for a methanolic extract of Oliveria decumbens was 7 h whereas for an ethanolic extract it was 28 h. Also, Oliveria decumbens extracts showed a synergistic effect in combination with doxycycline and tetracycline. In general, the similar values of MIC and MBC for Oliveria decumbens suggest that these extracts could act as bactericidal agents against Br. melitensis. In addition to Oliveria decumbens, Crocus sativus and Salvia sclarea also had good anti-brucella activity and these should be considered for further study.

In vitro assay for the anti-brucella activity of medicinal plants against tetracycline-resistant Brucella melitensis *

Science.gov (United States)

Motamedi, Hossein; Darabpour, Esmaeil; Gholipour, Mahnaz; Seyyed Nejad, Seyyed Mansour

2010-01-01

Brucellosis, a zoonosis caused by four species of brucella, has a high morbidity. Brucella melitensis is the main causative agent of brucellosis in both human and small ruminants. As an alternative to conventional antibiotics, medicinal plants are valuable resources for new agents against antibiotic-resistant strains. The aim of this study was to investigate the usage of native plants for brucellosis treatment. For this purpose, the anti-brucella activities of ethanolic and methanolic extracts of Salvia sclarea, Oliveria decumbens, Ferulago angulata, Vitex pseudo-negundo, Teucrium polium, Plantago ovata, Cordia myxa, and Crocus sativus were assessed. The activity against a resistant Br. melitensis strain was determined by disc diffusion method at various concentrations from 50–400 mg/ml. Antibiotic discs were also used as a control. Among the evaluated herbs, six plant (Salvia sclarea, Oliveria decumbens, Ferulago angulata, Vitex pseudo-negundo, Teucrium polium, and Crocus sativus) showed anti-brucella activity. Oliveria decumbens was chosen as the most effective plant for further studies. A tested isolate exhibited resistance to tetracycline, nafcillin, oxacillin, methicillin, and colistin. Minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values for Oliveria decumbens against resistant Br. melitensis were the same (5 mg/ml), and for gentamicin they were both 2 mg/ml. Time-kill kinetics for a methanolic extract of Oliveria decumbens was 7 h whereas for an ethanolic extract it was 28 h. Also, Oliveria decumbens extracts showed a synergistic effect in combination with doxycycline and tetracycline. In general, the similar values of MIC and MBC for Oliveria decumbens suggest that these extracts could act as bactericidal agents against Br. melitensis. In addition to Oliveria decumbens, Crocus sativus and Salvia sclarea also had good anti-brucella activity and these should be considered for further study. PMID:20593515

Oxidizable carbon fractions in Red Latosol under different management systems Frações oxidáveis do carbono em Latossolo Vermelho sob diferentes sistemas de manejo

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Roni Fernandes Guareschi

2013-06-01

Full Text Available The aim of this study was to evaluate the oxidizable fractions of organic C in a Red Latosol in an area of cerrado under a no-tillage system (NT with different years of implantation, and to compare them to areas of native cerrado and pasture. The experimental design used was completely randomized with five replications. Treatments consisted of five areas: native cerrado (NC "stricto sensu"; pasture (PA planted with Brachiaria decumbens; NT with 3 (NT3; NT with 15 (NT15 and NT with 20 (NT20 years of implantation. There was an increase in the ground-surface mass of vegetable residue as a function of the time of implantation of the NT. An increase in C content and the carbon-management index (CMI can be seen as a function of the time of implantation of the NT. In the area of NT20 the greatest values of C were quantified, compared to the area of cerrado. In general, there are increased labile and stable MOS fractions as a function of the implantation time of the NT, while the areas SPD15 and SPD20 present a C content among fractions, respectively similar and/or superior to the area of NC. Regardless of the area evaluated, a predominance of the more stable MOS fractions (F3+F4 can be seen. The area of PA, due to inadequate management, shows a more advanced stage of degradation when compared to the other areas, as there is a large reduction in the levels of total C, of C in the more labile and stable MOS fractions, as well as lower CMI values.Objetivou-se com este trabalho avaliar as frações oxidáveis de C orgânico em um Latossolo Vermelho em área de cerrado sob sistema de plantio direto (SPD com diferentes anos de implantação, e compará-las a áreas de cerrado nativo e pastagem. O delineamento utilizado foi inteiramente casualizado, com cinco repetições. Os tratamentos consistiram de cinco áreas: cerrado nativo (CE "stricto sensu"; pastagem plantada (PA com Brachiaria decumbens; SPD com 3 (SPD3; SPD com 15 (SPD15 e SPD com 20 (SPD20 anos

Redução de inóculo de Aphelenchoides besseyi em sementes de Brachiaria brizantha tratadas com óleos essenciais

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Thalita Suelen Avelar Monteiro

2014-07-01

Full Text Available Óleos essenciais foram testados com o objetivo de controlar Aphelenchoides besseyi em sementes de Brachiaria brizantha cv. 'Marandu'. Sementes naturalmente infestadas por A. besseyi foram tratadas com óleos essenciais de mostarda (Brassica nigra, canela (Cinnamomum zeylanicum, verbena (Lippia citriodora e Bioprotector (r (produto comercial composto por extratos e óleos essenciais derivados de plantas, nas concentrações de 0,5% e 1,0%. Avaliou-se também o efeito dos tratamentos após aplicação direta nos juvenis (ensaio in vitro. Todos os óleos tiveram sua efetividade reduzida no ensaio em semente (in vivo em relação ao ensaio in vitro. Os tratamentos não erradicaram o nematoide das sementes, sendo que os óleos essenciais de canela e verbena, nas concentrações 0,5% e 1,0%, Bioprotector (r a 1,0% e óleo de mostarda a 1,0% reduziram o nível populacional do nematoide em sementes contaminadas. O óleo de mostarda a 1,0% destacou-se dos demais por ter apresentado ação nematicida sem alterar a germinação das sementes.

Influência de Brachiaria brizantha nas características fisiológicas relacionadas a fotossíntese e uso eficiente da água em cana-de-açúcar Influence of Brachiaria brizantha in physiological characteristics related to photosynthesis and efficient use of water in sugarcane

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L Galon

2011-01-01

Full Text Available O aumento da população das plantas daninhas eleva a habilidade competitiva dessas com as plantas cultivadas, podendo causar interferência nos aspectos fisiológicos das culturas. Objetivou-se com o trabalho avaliar a interferência de populações de Brachiaria brizantha nas características relacionadas a atividade fotossintética e o uso eficiente da água das cultivares de cana-de-açúcar RB72454, RB867515 e SP80-1816. Foi conduzido um experimento a campo, onde os tratamentos foram constituídos por 12 populações de plantas de B. brizantha que emergiram juntamente com a cultura. Aos 120 dias após a emergência da cana-de-açúcar foram realizadas as avaliações da concentração de CO2 subestomático (Ci - µmol mol-1, a atividade fotossintética (A - µmol m-2 s-1, a condutância estomática (Gs - mol m-1 s-1, a taxa de transpiração (E, a eficiência do uso da água (EUA e a massa seca da parte aérea (SDM - g por planta da cultura. Todas as variáveis fisiológicas e a massa seca da cultivar RB72454 foram afetadas pelo aumento da densidade das plantas de B. brizantha, bem como a transpiração da cultivar RB867515. A cultivar RB72454 apresenta menor habilidade competitiva com as plantas daninhas e a atividade fotossintética é limitada por fatores que reduzem o influxo de CO2 para o interior da folha.The increase in density of weeds increases also its competitive ability, which affects the physiological aspects of crops. This study aimed to evaluate the interference of increasing densities of Brachiaria brizantha over sugarcane varieties RB72454, RB867515 and SP80-1816 based on physiological variables related to the photosynthesis rate. For this, a field was installed, being treatments composed by 12 densities of the competitor, ranging from 0 to 112 plants m-2, emerged simultaneously to the crop. At 120 days after crop emergence the substomatal CO2 concentration (Ci - µmol mol-1, photosynthetic activity (A - µmol m-2 s-1

Structural characteristic of the Eastern Plains soils of Colombia, submitted to several handling systems

International Nuclear Information System (INIS)

Amezquita, E; Saenz J I; Thomas, R J; Vera, R R; Hoyos, P; Molina, D L; Chavez, L F

1997-01-01

Soil productivity and sustainability depends on the building and/or conservation of an adequate and dynamic equilibrium between physical, chemical and biological properties and processes in the volume of soil explored by roots, so that there is no constraints in the availability of water and nutrients to plants. Soil structure is one of the soil properties that are more vulnerable to the intensity of use in tropical soils. Aggregate size distribution, aggregate stability and pore size distribution are some of the attributes that are usually used to describe structural changes and can act as indicators of structural sustainability. This paper presents and discusses the behavior of these attributes under different soil management treatments (native savanna, Brachiaria alone; Brachiaria + legume and monocrop) in the Colombian Eastern plains soil classified as Typic haplustox Kaolinitic iso-hyperthermic. These results showed highly statistical significant differences between treatments in the parameters studied and allow concluding that aggregate size distribution and stability could be indicators of susceptibility to degradation

Genetic diversity and population structure analysis of the tropical pasture grass Brachiaria humidicola based on microsatellites, cytogenetics, morphological traits, and geographical origin.

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Jungmann, L; Vigna, B B Z; Boldrini, K R; Sousa, A C B; do Valle, C B; Resende, R M S; Pagliarini, M S; Zucchi, M I; de Souza, A P

2010-09-01

Brachiaria humidicola (Rendle) Schweick. is a warm-season grass commonly used as forage in the tropics. Accessions of this species were collected in eastern Africa and massively introduced into South America in the 1980s. Several of these accessions form a germplasm collection at the Brazilian Agricultural Research Corporation. However, apomixis, ploidy, and limited knowledge of the genetic basis of this germplasm collection have constrained breeding activities. The objectives of this work were to identify genetic variability in the Brazilian B. humidicola germplasm collection using microsatellite markers and to compare the results with information on the following: (1) collection sites of the accessions; (2) reproductive mode and ploidy levels; and (3) genetic diversity revealed by morphological traits. The evaluated germplasm population is highly structured into four major groups. The sole sexual accession did not group with any of the clusters. Genetic dissimilarities did not correlate with either geographic distances or genetic distances inferred from morphological descriptors. Additionally, the genetic structure identified in this collection did not correspond to differences in ploidy level. Alleles exclusive to either sexual or apomictic accessions were identified, suggesting that further evaluation of the association of these loci with apospory should be carried out.

Induced mutation studies with Brachiaria brizantha Stapf. and some indica rice varieties from Ceylon

Energy Technology Data Exchange (ETDEWEB)

Ganashan, P [Agricultural Research Station, Maha-Illuppallama, Ceylon (Sri Lanka)

1970-03-01

Non-imbibed seeds of Brachiaria brizantha were irradiated with doses of {sup 60}Co gamma rays ranging from 7.5 to 75 kR and fresh stem cuttings containing three nodes were irradiated with doses ranging from 7.5 to 45 kR. Chromosome counts were made using the Carnoy method. There was no germination at 75 kR, and 18% germination at 60 kR with no survival of the seedlings. At the other doses germination and seedling survival decreased from 56% and 100% respectively for the control to 42% and 46% respectively at 45 kR. There were no chlorophyll mutants at 7.5 kR, while a few were observed among seedlings at the higher doses. In the stem cuttings establishment was poor and morphological variations were observed at all doses above 15 kR. A mutant of desirable plant type was obtained from the 45-kR seed treatment with an erect growth habit, reduced pubescence, short internodes, profuse tillering and rapid regrowth compared with the parent. Four indica rice varieties, H-4, H-8, H-7 and Pachchaiperumal 2462/11 (PP 2462/11), were subjected to gamma rays, neutrons and ethyl methane sulphonate (EMS) treatments. The LD{sub 50} level for gamma rays was 50 to 60 kR, for neutrons 1600 R and for EMS 0.4%. Germination and final plant stand in the M{sub 1} generation were affected only slightly by the neutron treatments, but were greatly reduced by EMS, and gamma irradiation above 35 kR. The final plant stand of the variety PP 2462/11 was most reduced by all the mutagens. In the M{sub 2} generation there was segregation for chlorophyll mutants, of the albina, chlorina, xantha, virescens and zebrina types. Other macro-mutations observed were for grain size and shape, plant height, flowering date and sterility. Grass clump types were found occasionally. (author)

Reduction of phosphorus concentration in mineral supplement on fertility rate, maternal ability and costs of beef cows reared in pastures of Urochloa decumbens.

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Costa, Rogério Magnoli; Ponsano, Elisa Helena Giglio; de Souza, Vinícius Carneiro; Malafaia, Pedro

2016-02-01

Manufacturing and marketing of mineral mixtures with less than 40 g kg(-1) phosphorus (P) is prohibited under Brazilian regulations, although scientific evidence rejects this recommendation. Considering the hypothesis that P levels in commercial mineral supplements can be reduced without affecting animal performance and health, the objective of this experiment was to evaluate the effects of reducing the concentration of P in the mineral supplement (from 40 to 18 g kg(-1)) of a herd of beef cows grazing tropical pastures of signal grass (Urochloa decumbens). The experiment was carried out in the savanna region of Mato Grosso do Sul, Brazil, during the years 2011 to 2013. Variables analyzed included pregnancy rate, calving interval, weight of calves at weaning, and cost of mineral supplementation. There were no changes in the reproductive parameters of the herd and the weight at weaning of the calves. However, the cost of mineral supplementation was significantly lower when the herd was supplemented with the mineral mix containing only 18 g kg(-1) P. Phosphorus concentration of the forage was analyzed monthly during 1 year and averaged 1.9 ± 0.45 g kg(-1) DM. Thus, it appears possible to reduce P content and cost of mineral supplementation without any adverse effects on the health and productivity of beef cattle herds in the State of Mato Grosso do Sul. However, the final decision should be made based on the clinical-nutritional examination and by constant technical assistance to the farm.

Impacts of water erosion on soil physical properties of an Oxisol and an Inceptisol in the Eastern Plains of Colombia

International Nuclear Information System (INIS)

Obando, Franco H

1999-01-01

On the basis of soil losses records during 10 years, three levels of water erosion were established for two soil (Typical Hapludox and Oxic Dystropept) located on high and medium terraces of alluvial flat plain of piedmont in the Eastern Plains in La Libertad Research Center of CORPOICA. Eighteen 3 x 10 m 2 run-off plots were fitted out on a nonrandom arrangement of nine plots by landscape and three soil use and management treatments: zero grazing Brachiaria decumbens pasture for six years, up land rice, soybean and maize rotations for six years and bare soil for 10 years. Soil losses under these treatments allowed to define three degrees of erosion: slight (N 3 moderate (N 2 ) and severe (N 3 ) respectively. From each plot soil samples were taken at two depths for physical analyses. infiltration and resistance to cone penetration were measured in the field. Without exception water erosion produced a detrimental effect on soil physical properties and the hydrological function of both experimental soils. Water retention capacity for N 2 and N 3 erosion levels did not present significant differences. Weighed mean diameter, DPM, of water stable aggregates was significantly greater on in the slightly (N 1 ) erosion level. Bulk density presented values significantly higher at 0-1 cm depth on both a soils

Performance and nutritional evaluation of beef cattle raised on pasture, castrated at different ages, with and without supplementation

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Anilza Andréia da Rocha

2012-04-01

Full Text Available The objective of this study was to evaluate performance and nutritional traits of beef cattle raised on pastures, castrated at different ages, with and without supplementation. Forty-four crossbred young bulls with predominance of Zebu breed at initial average age of 120±30 days were used in the experiment. Animals were distributed in a completely randomized design in a factorial arrangement with four ages of castration and two supplementation systems. The animals were distributed into four groups and placed on Brachiaria decumbens Stapf pastures, where they were fed concentrate supplementation or mineral salt ad libtum (control. Animals were castrated at 120, 240 and 360 days of age with average body weight of 115, 175 and 276 kg, castrated or not, in each supplementation group. Concentrate supplement composition and the amount supplied to the animals varied according to the time of the year and development phase of the animals. Trials were carried out to evaluate nutritional variables in each of the following phases: suckling, growth in the dry season and growth in the dry/rainy transition season. Concentrate supplementation improved the use of pasture, although it may have caused substitutive effect in all seasons evaluated. Castration of the animals before the dry season impaired animal development until the following dry/rainy transition season, especially when carried out during weaning. Concentrate supply may reduce some effects of this stress.

Parámetros indicadores de valor nutritivo en cinco pastos tropicales en la época lluviosa en el trópico seco de Cota Rica

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Rafael Angel Arroyo

2016-03-01

Full Text Available This essay was carried out in Hojancha, Guanacaste to evaluate the nutritive values of the following grasses: jaragua (Hyparrhenia rufa (Nees, african star grass (Cynodon nlenfuensis (L(Pers, transvala (Digitaria decumbens veranero (Andropogon gayanus(Kunth y congo (Brachiaria ruziziensis(Germain et Everard, under three cut intervals (28, 35 and 42 days. The evaluated variables were: Dry Matter Production (DMP, kg/ha/cut, In vitro Dry Matter Digestibility (IVDMD, %, Digestible Dry Matter (DDM, kg/ha/cut, Crude Protein Content (CP, %, Crude protein production (CPP, kg/ha/cut, Digestible Crude Protein Production (DCPP, kg/ha/cut, Ruminal Dry Matter Disappeareance (RDMD, %/hour, Ruminal Dry Matter Disappeareance Mean Time (RDMDMT, hours. The largest DMP was found for the veranero grass at 28 and 35 day intervals (1527,5 and 2424,4 kg/ha/cut while at the 42 day interval the congo grass (2886,8 kg/ha/cut had the largest DMP, followed by veranero grass with 2705,0 kg/ha/cut. The veranero and transvala grasses showed the highest RDMD and RDMDMT as compared to the other grasses in the study, as a consequence of their better chemical composition. Between the jaragua and veranero grasses there were no differences with respect to their chemical composition and ruminal characteristics. The poorest DMP, chemical composition (excluding CP and RDMD was shown by the african star grass.

Correlación de la productividad de un forraje con las propiedades físicas de un Ultisol en Aquidauana

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Rafael Montanari

2013-02-01

Full Text Available Los sistemas de producción de ganadería y de manejo de pastos alteran las propiedades físicas del suelo, reflejados en la productividad y la composición vegetal. El objetivo de este trabajo fue indicar las propiedades físicas del suelo con mejores correlaciones lineales y espaciales para obtener sitios específicos de manejo del suelo. Se analizaron las correlaciones lineales y espaciales entre la productividad de la materia seca del forraje de Brachiaria decumbens (Stapf y algunas propiedades físicas de un Ultisol en dos profundidades (0,00-0,10 m y 0,10-0,20 m. Para la colecta de los datos fue instalada una red geoestadística con 121 puntos de muestreo. La productividad del forraje varió aleatoriamente y no siguió patrones espaciales, presentando el efecto pepita puro. La resistencia mecánica del suelo a la penetración y la humedad del suelo en la capa de 0,10-0,20 m, son importantes indicadores de la calidad física del suelo. El aumento de estas propiedades en el cultivo del forraje, promovió la reducción de la materia seca del forraje. Por lo tanto, estos indicadores representan confiabilidad para estimar la productividad del forraje.

Efeito de pontas de pulverização na deposição e na dessecação em plantas de Brachiaria brizantha Nozzle effect on deposition and desiccation on Brachiaria brizantha plants

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N.V. Costa

2008-01-01

Full Text Available Objetivou-se com este trabalho avaliar a eficiência de pontas de pulverização com diferentes vazões e tamanhos de gotas na deposição e na dessecação de plantas de Brachiaria brizantha cv. Marandu, além da quantificação das perdas da calda de pulverização para o solo. O delineamento experimental adotado foi o de blocos casualizados, com quatro repetições. Cada unidade experimental constituiu-se de três linhas de 5 m de comprimento, espaçadas de 1 m. A aplicação dos tratamentos foi realizada 16 meses após a semeadura da braquiária; 40 dias antes da aplicação foi realizada uma roçagem para uniformização da área. Foram avaliadas as pontas de pulverização de jato plano XR 11001 VS (100 L ha-1 e XR 11002 VS (200 L ha-1, jato cônico TX-4VS (100 L ha-1 e TX-8 VK (200 L ha-1, ponta com indução de ar AI 11002 VS (200 L ha-1 e jato plano duplo TJ60 11002 VS (200 L ha-1. A calda foi aplicada com o herbicida glyphosate na dose de 1.800 g ha-1, mais um traçador (FD&C nº1 2.000 ppm. Foram coletados imediatamente após a aplicação da calda 25 perfilhos por repetição, sendo lavadas separadamente as folhas e caules de cada perfilho em 150 ml de água destilada, para posterior quantificação do traçador em espectrofotômetro. Os dados foram ajustados à curva de regressão pelo modelo de Gompertz. Todas as pontas utilizadas foram eficientes na dessecação das plantas de B. brizantha, independentemente do volume utilizado, o que evidencia a possibilidade de redução do volume de aplicação e da dosagem do herbicida na dessecação de pastagens, considerando-se a utilização de herbicidas sistêmicos. Ressalta-se que houve diferença na quantidade e na uniformidade de distribuição da calda pulverizada nos alvos avaliados em função da ponta testada e, conseqüentemente, do volume utilizado.The objective of this work was to evaluate the effect of spray nozzles with different flows and droplet size on the deposition and

Degradable polyphosphazene/poly(alpha-hydroxyester) blends: degradation studies.

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Ambrosio, Archel M A; Allcock, Harry R; Katti, Dhirendra S; Laurencin, Cato T

2002-04-01

Biomaterials based on the polymers of lactic acid and glycolic acid and their copolymers are used or studied extensively as implantable devices for drug delivery, tissue engineering and other biomedical applications. Although these polymers have shown good biocompatibility, concerns have been raised regarding their acidic degradation products, which have important implications for long-term implantable systems. Therefore, we have designed a novel biodegradable polyphosphazene/poly(alpha-hydroxyester) blend whose degradation products are less acidic than those of the poly(alpha-hydroxyester) alone. In this study, the degradation characteristics of a blend of poly(lactide-co-glycolide) (50:50 PLAGA) and poly[(50% ethyl glycinato)(50% p-methylphenoxy) phosphazene] (PPHOS-EG50) were qualitatively and quantitatively determined with comparisons made to the parent polymers. Circular matrices (14mm diameter) of the PLAGA, PPHOS-EG50 and PLAGA-PPHOS-EG50 blend were degraded in non-buffered solutions (pH 7.4). The degraded polymers were characterized for percentage mass loss and molecular weight and the degradation medium was characterized for acid released in non-buffered solutions. The amounts of neutralizing base necessary to bring about neutral pH were measured for each polymer or polymer blend during degradation. The poly(phosphazene)/poly(lactide-co-glycolide) blend required significantly less neutralizing base in order to bring about neutral solution pH during the degradation period studied. The results indicated that the blend degraded at a rate intermediate to that of the parent polymers and that the degradation products of the polyphosphazene neutralized the acidic degradation products of PLAGA. Thus, results from these in vitro degradation studies suggest that the PLAGA-PPHOS-EG50 blend may provide a viable improvement to biomaterials based on acid-releasing organic polymers.

Fotossíntese foliar do capim-xaraés [Brachiaria brizantha (A. Rich.) Stapf. cv. Xaraés] e modelagem da assimilação potencial de dosséis sob estratégias de pastejo rotativo

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Pedreira,Bruno Carneiro e; Pedreira,Carlos Guilherme Silveira

2007-01-01

Objetivou-se com este trabalho quantificar a fotossíntese foliar ao longo do período de rebrotação e modelar a fotossíntese de dosséis vegetativos em função da arquitetura foliar e do ambiente luminoso em pastagens de capim-xaraés [Brachiaria brizantha (A. Rich.) Stapf.] submetidas a estratégias contrastantes de pastejo rotativo. Na fase inicial de rebrotação, o potencial fotossintético foi pequeno, em média 10,4 µmol CO2 m-2 s-1 e, no tratamento de maior intervalo de pastejo (100% IL), esse ...

Phytotoxic substances with allelopathic activity may be central to the strong invasive potential of Brachiaria brizantha.

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Kato-Noguchi, Hisashi; Kobayashi, Ai; Ohno, Osamu; Kimura, Fukiko; Fujii, Yoshiharu; Suenaga, Kiyotake

2014-04-15

The grass Brachiaria brizantha, native to eastern Africa, becomes naturalized and dominant quickly in the non-native areas. It was hypothesized that phytotoxic chemical interaction between this plant and native plants may play an important role in the invasion of B. brizantha. However, no potent phytotoxic substance has been reported in this species. Therefore, we investigated possible allelopathic activity and searched for phytotoxic substances with allelopathic activity in B. brizantha. An aqueous methanol extract of B. brizantha inhibited the growth of roots and shoots of garden cress (Lepidium sativum), lettuce (Lactuca sativa), timothy (Phleum pratense) and ryegrass (Lolium multiflorum) seedlings. The extract was purified by several chromatographic runs and three allelopathically active substances were isolated and identified by spectral analysis as (6R,9R)-3-oxo-α-ionol, (6R,9S)-3-oxo-α-ionol and 4-ketopinoresinol. (6R,9R)-3-Oxo-α-ionol and (6R,9S)-3-oxo-α-ionol inhibited root and shoot growth of garden cress at concentrations greater than 30 and 10 μM, respectively. The activity of (6R,9S)-3-oxo-α-ionol was 5.3- to 6.2-fold that of (6R,9R)-3-oxo-α-ionol. The stereochemistry of the hydroxyl group at position C-9 may be important for the inhibitory activities of those compounds. 4-Ketopinoresinol inhibited root and shoot growth of garden cress at concentrations greater than 30 μM. The growth inhibitory activity of (6R,9S)-3-oxo-α-ionol was the greatest and followed by 4-ketopinoresinol and (6R,9R)-3-oxo-α-ionol. These results suggest that those phytotoxic substances may contribute to the allelopathic effect caused by B. brizantha and may be involved in the invasion of B. brizantha. Copyright © 2013 Elsevier GmbH. All rights reserved.

Seleção de genótipos de Brachiaria Ruziziensis quanto ao alumínio em solução nutritiva: II: Avaliação da tolerância ao alumínio Brachiaria Ruziziensis genotypes selection: II: Evaluation of the aluminum tolerance

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Paulo Sérgio Balbino Miguel

2011-01-01

Full Text Available O alumínio, em solos ácidos, é um dos principais responsáveis pela baixa produtividade de culturas. O objetivo deste trabalho foi avaliar a variabilidade genética da Brachiaria ruziziensis para a tolerância ao alumínio. Foram utilizados 10 genótipos da espécie referida, crescidas em vasos com 0, 30 e 60 mg/L de alumínio em solução nutritiva. Foi utilizado o delineamento inteiramente casualizado em esquema fatorial, com seis repetições e parcelas de uma planta por vaso. Foram avaliados: a produção de massa verde da parte aérea e raízes (MVPA e MVR, a produção de matéria seca da parte aérea e raízes (MSPA e MSR, o incremento no crescimento da parte aérea e das raízes (IPA e IR, expresso pela diferença entre o crescimento final e o inicial, e o incremento no número de perfilhos (INP. O aumento nas concentrações de alumínio provocou decréscimos para as médias de todas as características avaliadas, excetuando o IR. A ausência de diferenças do genótipo 8 para seis das sete características analisadas, com exceção da MVPA, demonstra ser ela a mais promissora para estudos posteriores em melhoramento, visando maior produtividade em solos ácidos. Os resultados evidenciaram a existência de variabilidade genética entre os genótipos avaliados para a tolerância ao alumínio tóxico, sendo possível identificar materiais mais produtivos na presença desse metal.In acid soils, the aluminum is responsible for the low cultures productivity. The objective of this work was to evaluate the Brachiaria ruziziensis genetic variability for the aluminum tolerance.10 genotypes of that species were used, grown in vases with 0, 30 and 60 mg/L of aluminum in nutritious solution. A completely randomized design under 10 x 3 factorial, with six replicates. The following variables were evaluated: the green mass production of the aerial part and roots (MVPA and MVR, the dry matter production of the aerial part and roots (MSPA and MSR

Simulação e validação de parâmetros da cinética digestiva em novilhos mestiços suplementados a pasto, por intermédio do sistema in vitro de produção de gases Simulation and validation of digestive kinetic parameters using an in vitro gas production system in crossbred steers with pasture supplementation

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Edenio Detmann

2005-12-01

production technique. In vivo estimates were obtained from five Holstein x Zebu steers averaging 304 kg of body weight and 24 months of age that were grazing on five paddocks of Brachiaria decumbens (0.34 ha. The supplements fed to the steers (4 kg/animal/day contained: grounded corn, whole soybean, urea, ammonium sulfate, and mineral salt and the following crude protein levels: 12, 16, 20, or 24% on as-fed basis. Statistical analyses were performed as a 4 x 4 Latin square design with 21-days periods. The fifth animal was not supplemented and was used only for descriptive comparisons. Data were obtained by regression of values predicted in vitro on values observed in vivo. Use of digestion rates obtained in vitro resulted in under- and over-estimation of the ruminal degradation of fiber (FC and nonfiber (NFC carbohydrates with overall biases of -25.27% and +33.58%, respectively. No significant relationship was found between predicted versus observed values for microbial efficiency showing lack of relationship between predicted and observed values for the abomasum flow of microbial nitrogen. Results showed that the ruminal incubation of feeds separately underestimates the digestion rate of FC.

Effect of root extracts of Brachiaria humidicola on fertilizer nitrogen use efficiency in rice and wheat crops

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Meena, H.M.; Sachdev, M.S.; Sachdev, Pamila

2010-01-01

A pot experiment was conducted in 2009-2010 to study the effect of root extracts of Brachiaria humidicola on fertilizer nitrogen use efficiency in rice and wheat crops. The experiment was conducted with rice (var. Pusa Sugandh-5) as the test crop in kharif season and in rabi season wheat (var. HD-2894) was grown as the test crop with seven treatments. Three level of nitrogen were applied as 30, 60 and 90 mg N kg -1 soil through '1 5 N labelled (NH 4 ) 2 SO 4 as source of N. Recommended dose of P (30 mg P 2 O 5 kg -1 soil) and K (30 mg K 2 O kg -1 soil) through KH 2 PO 4 and KCI were applied. Nitrogen levels and inhibitors had significant effect on rice grain yield. It was maximum 20.37 g pot -1 in case of T 4 (buffer solution extract) and low 13.10 g pot -1 in T 7 (control). Nitrogen uptake in rice straw was found more in BNI treatments as compared to plant based (neem oil coating) and standard nitrification inhibitors. Nitrogen use efficiency in rice plant was highest in case of T 1 (70 % alcohol extract) 41.90 followed by T 4 (buffer solution extract) 41.30. Among the treatments T 5 (neem oil coating) performed better in wheat yield as compared to other treatments. Nitrogen uptake and NUE were maximum in T 3 (salt solution extract) followed by T 5 (neem oil coating) in wheat crop. The maximum nitrogen use efficiency was observed at 60 mg N kg -1 soil as compared to other levels. (author)

Digestibilidade dos compostos nitrogenados insolúveis em detergente ácido em bovinos manejados em pastagem de capim-braquiária Digestibility of acid detergent insoluble nitrogen in cattle grazing signalgrass

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Edenio Detmann

2006-08-01

Full Text Available Objetivou-se neste estudo avaliar as digestibilidades total e parcial dos compostos nitrogenados insolúveis em detergente ácido (NIDA em bovinos em pastejo. Foram utilizados cinco novilhos mestiços Holandês x Zebu (24 meses de idade e 304 kg de PV, canulados no esôfago, rúmen e abomaso, manejados em cinco piquetes de Brachiaria decumbens (0,34 ha, recebendo ou não suplementação com concentrado. O experimento foi realizado em quatro períodos experimentais de 21 dias, entre agosto e novembro de 2000. A avaliação da forragem selecionada pelos animais foi feita em amostras de extrusa esofágica e a estimativa do consumo e dos fluxos fecais e abomasais de MS e NIDA, foram estimados por intermédio de indicadores interno e externo. A avaliação estatística da digestibilidade do NIDA foi conduzida por ajustamento de equação de regressão linear, desconsiderando o parâmetro intercepto e utilizando-se como variáveis independente e dependente as estimativas de influxo e efluxo de NIDA, respectivamente. Os desvios do coeficiente de regressão a partir do valor paramétrico 1,0 foram considerados estimativas de digestibilidade. A comparação entre o consumo e os fluxos abomasal e fecal de NIDA indicou haver digestibilidade desta fração em nível total, atribuída exclusivamente a eventos intestinais (30,7%, uma vez que não foi observada digestibilidade no compartimento ruminal. Esse comportamento indica que o teor de NIDA de um alimento é somente indicador, e não preditor, da digestibilidade potencial dos compostos nitrogenados totais.The objective of this trial was to investigate ruminal, intestinal and total tract digestibility of acid detergent insoluble nitrogen (ADIN in grazing cattle. Five Holstein x Zebu steers averaging 304 kg of body weight and 24 months of age and fitted with esophageal, ruminal and abomasal cannulas were used in this study. Animals were maintained in five 0.34-ha paddocks of Brachiaria decumbens with or

Exigências nutricionais em macronutrientes minerais (Ca, P, Mg, Na e K para novilhos de diferentes grupos genéticos Macrominerals (Ca, P, Mg, Na, and K requirements for young bulls from different genetic groups

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Fernando de Paula Leonel

2006-04-01

Full Text Available Determinaram-se as exigências em macronutrientes minerais (Ca, P, Mg, Na e K utilizando-se 44 novilhos não-castrados, pertencentes a quatro grupos genéticos (Nelore; F1 Nelore x Aberdeen-Angus; F1 Nelore x Pardo-Suíço e F1 Nelore x Simental, com média de 10 e 11 meses de idade e peso vivo inicial de 362 ± 35 kg. A ração experimental foi composta de feno de capim-braquiária (Brachiaria decumbens, Stapf., farelo de soja, milho (grão moído, melaço em pó e suplementos de macro e micronutrientes inorgânicos. As exigências líquidas para ganho de peso, em cada macronutriente, foram obtidas por meio da derivada primeira de suas respectivas equações, estimadas a partir de regressão não-linear do conteúdo do nutriente (Ca, P, Mg, Na e K, em função do peso de corpo vazio do animal. Para conversão do peso vivo em peso de corpo vazio, utilizou-se a equação obtida a partir da regressão do peso corporal vazio dos animais experimentais em função de seus pesos imediatamente antes do abate. As exigências de mantença foram estimadas de acordo com as recomendações do NRC e ARC e os coeficientes de absorção adotados para os cinco macronutrientes foram aqueles propostos pelo ARC. O teste de identidade de modelos indicou não haver diferenças entre as equações de regressão para os minerais entre os quatro grupos genéticos estudados. Não foram verificadas, pela análise de variância, diferenças entre as exigências de macrominerais entre os diferentes grupos genéticos.The objective of this trial was to determine the macrominerals requirements (Ca, P, Mg, Na, and K for young bulls from different genetic groups. Forty-four young bulls from the following genetic groups were used: Nellore, F1 Nellore x Aberdeen-Angus, F1 Nellore x Brown Swiss, and F1 Nellore x Simmental. Animals averaged 362 ± 35 kg of initial body weight and between 10 to 11 months of age. Diet contained signal grass hay (Brachiaria decumbens, Stapf., soybean

Tropical terrestrial model ecosystems for evaluation of soil fauna and leaf litter quality effects on litter consumption, soil microbial biomass and plant growth Efeitos de fauna de solo e qualidade de liteira sobre o consumo, biomassa microbiana e crescimento de plantas em modelo de ecossistemas terrestres tropicais

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Bernhard Förster

2009-08-01

Full Text Available The aim of this work was to evaluate whether terrestrial model ecosystems (TMEs are a useful tool for the study of the effects of litter quality, soil invertebrates and mineral fertilizer on litter decomposition and plant growth under controlled conditions in the tropics. Forty-eight intact soil cores (17.5-cm diameter, 30-cm length were taken out from an abandoned rubber plantation on Ferralsol soil (Latossolo Amarelo in Central Amazonia, Brazil, and kept at 28ºC in the laboratory during four months. Leaf litter of either Hevea pauciflora (rubber tree, Flemingia macrophylla (a shrubby legume or Brachiaria decumbens (a pasture grass was put on top of each TME. Five specimens of either Pontoscolex corethrurus or Eisenia fetida (earthworms, Porcellionides pruinosus or Circoniscus ornatus (woodlice, and Trigoniulus corallinus (millipedes were then added to the TMEs. Leaf litter type significantly affected litter consumption, soil microbial biomass and nitrate concentration in the leachate of all TMEs, but had no measurable effect on the shoot biomass of rice seedlings planted in top soil taken from the TMEs. Feeding rates measured with bait lamina were significantly higher in TMEs with the earthworm P. corethrurus and the woodlouse C. ornatus. TMEs are an appropriate tool to assess trophic interactions in tropical soil ecossistems under controlled laboratory conditions.O objetivo deste trabalho foi avaliar o modelo de ecossistema terrestre (TME como ferramenta para o estudo dos efeitos da qualidade da liteira, de invertebrados do solo e da fertilização mineral na decomposição da liteira e no crescimento das plantas em condições controladas. Foram coletados quarenta e oito cilindros de solo intacto (Latossolo Amarelo de 17,5 cm de diâmetro e 30 cm de comprimento em um seringal abandonado na Amazônia Central brasileira e mantidos a 28ºC em laboratório, por quatro meses. Folhas da liteira de Hevea pauciflora (seringueira, ou de Flemingia

Diversidad y cuantía de la flora en un pastizal disturbado y pastoreado de forma racional Diversity and quantity of the flora in a disturbed and rationally grazed pastureland

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R Machado

2009-09-01

Full Text Available Con el fin de estudiar los cambios en la diversidad y cuantía de la flora en un pastizal manejado de forma racional y disturbado por la quema, se determinó la composición botánica durante cuatro años y medio, utilizando un marco cuadrado en 20 puntos de cada cuartón. Al concluir el período experimental existió una fuerte hegemonía de las gramíneas y las leguminosas perennes con relación a las especies de otras familias con igual ciclo, tanto en número (22 vs 1 como en área cubierta (92,7 vs 0,004%. Un patrón similar se detectó en las especies anuales, independientemente de la familia. El área cubierta por las gramíneas se incrementó después de la quema y en las leguminosas tendió a disminuir, así como su número (7 vs 4. Panicum maximum cv. Likoni fue la especie predominante, al aumentar de 27,3 a 68,0%; Brachiaria decumbens se incrementó ligeramente (1,0 a 4,6%; mientras que Andropogon gayanus disminuyó (21,4 a 6,0%. Especies adventicias como Dichanthium annulatum, Dichanthium aristatum e Indigofera mucronata incrementaron o mantuvieron poblaciones fluctuantes; otras como Dichanthium caricosum y Centrosema molle disminuyeron; mientras que Acacia farnesiana y Alysicarpus vaginalis tendieron a desaparecer. Se concluye que en estas condiciones se creó una cubierta muy diferente a la que se produjo con un manejo racional intensivo aplicado con anterioridad y se corroboró la importancia del índice de composición de especies para explicar las variaciones que se producen en pastoreo.With the objective of studying the changes in the diversity and quantity of the flora in a pastureland rationally managed and disturbed by burning, the botanical composition was determined during four years and a half, using a square frame in 20 spots of each paddock. By the end of the experimental period there was a strong hegemony of grasses and perennial legumes with regards to the species from other families with equal cycle, in number (22 vs

Nutritive value and in situ rumen degradability of Marandu palisade grass at different locations within the pasture in a silvopastoral system with different babassu palm densities

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Xerxes M. Tosta

2015-09-01

Full Text Available The objective of this study was to evaluate the nutritive value and in situ rumen degradability of grass collected from different locations within the pasture in a silvopastoral system with different densities of trees. The silvopastoral system consisted of Urochloa (syn. Brachiaria brizantha cv. Marandu and the babassu palm, Orbignya sp. (now: Attaleia speciosa. We used a completely randomized design with a 3 x 3 factorial arrangement for nutritional value (3 differently shaded locations and 3 palm tree densities and a 3 x 3 x 3 factorial arrangement for dry matter (DM disappearance (3 locations, 3 palm densities and 3 incubation times. There was no effect of location within the pasture nor of palm tree density on the concentrations of NDF, ADF, lignin, cellulose and hemicellulose. However, location influenced the concentrations of crude protein (CP and DM, with highest CP in material grown in full sunlight. At all densities, DM disappearance at 96 h for pasture grown in full sunlight exceeded that for pasture grown in full shade. These factors need to be compounded with the possible depressant effect of trees on DM production of pasture when considering the benefits of silvopastoral systems.Keywords: Digestibility, fiber, Northeast Brazil, protein, tree-grass associations, Urochloa  brizantha.DOI: 10.17138/TGFT(3187-193

Evaluation of ruminal fluid in buffaloes produced extensively in pastures of Brachiaria brizantha in the state of Pará, Northern Brazil

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V. Duarte Cerqueira

2010-02-01

Full Text Available The examination of the ruminal fluid has great importance in the diagnosis of microbial and biochemical alterations of reticulum and rumen. In the state of Pará buffaloes are produced extensively, mainly in pastures of Brachiaria brizantha. The physiologic parameters of the ruminal content in buffaloes in this condition had not been determined. The objective of this study was to establish normal values for reticulum-ruminal fluid examination in buffaloes in pastures of B. brizantha. Twenty buffaloes of the Murrah breed were used. Samples of ruminal fluid were obtained during 4 days, twice a day, at 7:00am and 5:00pm. The aspect, color, smell, and the sedimentation and fluctuation period (TSF of the fluid were analyzed macroscopically. Physico-chemical analysis included pH, glucose fermentation, methilene blue reduction (RAM and total acidity. All animal had a green-olive ruminal fluid with viscous consistency, and aromatic smell. The pH varied from 6.95 to 7.03. The RAM test varied from 126.74 to 291.83 seconds and the TSF from 266.7 to 298.89 seconds. Glucose fermentation produced 0.69 to 0.78 ml of gas per hour. Total acidity was 18.11 to 18.32 UC. In the microbiologic examination the number of protozoa was 551,377.31 to 518,860.72 with predominance of Gram negative bacteria.

Uso de N-alcanos na estimativa da composição botânica em amostras com diferentes proporções de Brachiaria brizantha e Arachis pintoi Use of N-alkanes for estimations of botanical composition in samples with different proportions of Brachiaria brizantha and Arachis pintoi

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Cristiano Côrtes

2005-10-01

Full Text Available Este trabalho foi conduzido para se determinar a composição de n-alcanos (C24 a C36 em diferentes proporções de dietas hipotéticas de Brachiaria brizantha Stapf. cv. Marandu e Arachis pintoi Koprov & Gregory. cv. Amarillo (0; 15; 30; 45; 60 e 100% de Arachis pintoi e identificar a combinação de alcanos que permite calcular a composição botânica de dietas com o menor valor residual (real menos o estimado. As forragens foram amostradas no verão e os n-alcanos extraídos pelo método de saponificação direta, sendo identificados e quantificados por meio de análise de cromatografia gasosa. O alcano C34 foi utilizado como padrão interno. As proporções de A. pintoi nas dietas foram estimadas pela minimização do z (soma dos quadrados dos desvios entre a proporção real dos alcanos analisados e as proporções pré-estabelecidas (tratamentos, utilizando-se a equação de Duncan et al. (1999. Observou-se que houve predomínio das cadeias carbônicas ímpares e que a concentração total de n-alcanos decresceu à medida que se aumentou a proporção de A. pintoi nos tratamentos. Estimativas acuradas da composição botânica de misturas de A. pintoi com B. brizantha foram obtidas utilizando-se os alcanos C29, C31, C33 e C35. O alcano C35 foi fundamental para a qualidade das estimativas. Os resultados indicaram o grande potencial da técnica para estudos com animais em pastejo.This trial was carried out to determine the composition of n-alkanes (C24 to C36 in hypothetical diets comprising of pure Brachiaria brizantha Stapf. cv. Marandu and Arachis pintoi Koprov & Gregory. cv. Amarillo and mixtures of these two spececies with 15%, 30%, 45%, or 60% of Arachis pintoi; it also intended to identify the combination of alkanes that allows to calculate the botanical composition of diets with the smallest residual value (real less estimated values. The forages were sampled in the summer. The n-alkanes were extracted for the direct saponification

Soil microbial biomass in an agroforestry system of Northeast Brazil

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Rosane C. Rodrigues

2015-01-01

Full Text Available Agroforestry systems (AFS are considered alternative land use options to help prevent soil degradation and improve soil microbial biomass and organic C status. However, it is unclear how different densities of babassu palm [Attalea speciosa (syn. Orbignya phalerata], which is an important tree in Northeast Brazil, affect the soil microbial biomass. We investigated the soil microbial biomass C and activity under AFS with different densities of babassu palm associated with Brachiaria brizantha grass. Soil microbial biomass C (MBC, soil microbial biomass N (MBN, MBC:total organic C ratio, fluorescein diacetate hydrolysis and dehydrogenase activity showed highest values in plots with high density of babassu palm. On the other hand, the respiratory quotient (qCO2 was significantly greater in plots without babassu palm. Brachiaria brizantha in monoculture may promote C losses from the soil, but AFS with high density of babassu palm may increase the potential of soils to accumulate C.Keywords: Enzyme activity, tropical soil, babassu palm, silvopastoral system, soil quality.DOI: 10.17138/TGFT(341-48

Consumo e digestibilidade de novilhos Nelore sob pastagem suplementados com misturas múltiplas Intake and digestibility of Nelore steers grazing pasture and supplemented with multiple mixture

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L.O.F. Oliveira

2004-02-01

Full Text Available Estudou-se o efeito da suplementação com misturas múltiplas sobre o consumo, digestibilidade e desempenho de novilhos Nelore, em pastagens de Brachiaria brizantha Cv. Marandu, submetidos a quatro tratamentos. No tratamento um (T1, cada animal recebeu 800g/dia de suplemento contendo uréia como fonte de nitrogênio não protéico (NNP; no tratamento dois (T2, recebeu 800g/dia de mistura na qual a uréia foi substituída por amiréia como fonte de NNP; no tratamento três (T3, recebeu 1500g/dia de uma mistura com amiréia; e no tratamento quatro (T4= controle, recebeu sal mineral. Seis animais por tratamento foram utilizados para se medir o consumo pela técnica de indicador externo (óxido crômico, e 10 animais foram usados na avaliação de ganho de peso. Foram utilizados dois animais canulados no esôfago para coleta de amostra de extrusa. Os animais suplementados obtiveram ganhos de peso superiores (PThe effect of three multiple mixtures supplementation on intake, digestibility and performance of Nelore steers grazing pasture of Brachiaria decumbens CV Marandu was studied. The multiple mixtures (treatments - T were defined as: T1 - 800g of supplement with urea as crude protein source, T2 - 800g of mixture in which urea was replaced by starea, T3 - 1500g of starea, and T4 - mineral salt fed ad libitum as a control group. Six animals per treatment were given chromic oxide as a marker to measure intake and 10 animals per treatment were used to evaluate their performance. Two esophageal fistulated steers were used to collect samples of extruse. The animals fed on supplement diets showed higher weight gains (335, 419, 467g/animal than those from the control group (271g/animal. Dry matter digestibility were 56.7, 49.8, 48.9 and 45.5%, respectively, for T1, T2, T3 and T4. A positive correlation between dry matter digestibility and in vitro dry matter digestibility (P<0.05 was observed. Supplementation with multiple mixtures increased dry matter

Caracterización morfológica de 19 accesiones de Brachiaria brizantha en un suelo ácido

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Yuseika Olivera

Full Text Available El objetivo de esta investigación fue caracterizar una colección de 19 accesiones de Brachiaria brizantha, procedentes del Centro Internacional de Agricultura Tropical (CIAT, Colombia, que se conserva en el banco de germoplasma de la Estación Experimental de Pastos y Forrajes de Cascajal, Cuba. Se utilizaron descriptores internacionales para gramíneas forrajeras y otros de interés (17 en total, 13 cuantitativos y 4 cualitativos. Las mediciones y observaciones se realizaron en la fase vegetativa y en la reproductiva. El análisis de componentes principales permitió comprobar la existencia de una variabilidad relativamente alta, ya que el acumulado alcanzó 81,22 % en las cinco primeras componentes. En la componente uno, los indicadores con mayor influencia fueron: el número de espículas y de raquis, y el ancho de la inflorescencia. Con la utilización del análisis de conglomerados se diferenciaron seis grupos; en el grupo V, formado por dos accesiones (CIAT-16317 y CIAT-26290, se detectó que estas maximizaron los valores en varios indicadores. Esa variabilidad fenotípica es importante, ya que permite aseverar que se cuenta con un germoplasma de B. brizantha diferenciado, con una riqueza morfológica aceptable, la que se debe conocer para evitar duplicaciones. La caracterización de esta colección permitió comprobar que el mayor grado de diferenciación se encontró en los caracteres cuantitativos. Se sugiere realizar esta actividad como etapa inicial del proceso de evaluación, así como ensayos en los que se evalúen sus potencialidades para indicadores agroproductivos de interés, con fines selectivos.

PRODUCTION AND CHEMICAL-BROMATOLOGICAL COMPOSITION OF Brachiaria Brizantha CV. MARANDU FERTILIZED wITH SUINE LIQUID wASTE PRODUÇÃO E COMPOSIÇÃO QUÍMICO- BROMATOLÓGICA DA Brachiaria brizantha CV. MARANDU ADUBADA COM DEJETOS LÍQUIDOS DE SUÍNOS

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Eurídice de Paula Pinheiro

2007-09-01

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The present work evaluated the effects of the ap-plication of different amounts of liquid pig waste (LPw in the manuring of Brachiaria brizantha cv. Marandu in relation to the chemical manuring usually recommended, as the production and composition chemist - bromatológica during the period from January at April/00. The treatments consisted of T1 = it controls, T2 = chemical manuring (60 kg/ha of N in form of sulfate of ammonium, 30 kg/ha of P in form of simple superfosfato and 37,5 kg/ha of K in form of potassium chloride, T3 = 50 m³/ha, T4 = 100 m³/ha and T5 = 150 m³/ha, being the  LPw,manurings divided in three applications. The used experimental deli-neament was it of blocks complete casualizados, with four repetitions. They were appraised: production of dry matter (PMS (kg/ha, medium tenors of rude protein (PB, fiber in neutral detergent (NDF, fiber in acid detergent (ADF and hemicelulose (HC, besides the medium tenors of the macrominerals: match (P, potassium (K, calcium (Ca and magnesium (Mg. The manuring with dejections and the chemical manuring provided significant increments in PMS of the grass Marandu. The application of LPW influenced the composition bromatologyc of the forage, as well as the chemical composition. For the found results the application of 150 m3 of DLS can be recommended to substitute the recommended chemical manuring. 

KEY-WORDS: ADF, cruden protein, mineral macroelements, NDF, production of dry mater.

O presente trabalho avaliou os efeitos da aplicação de diferentes quantidades de dejetos líquidos de suínos (DLS na adubação da Brachiaria brizantha cv. Marandu em relação à adubação química normalmente recomendada, quanto à produção e à composição químico-bromatológica durante o período de janeiro a abril de 2000. Os tratamentos consistiram em T1= controle, T2= adubação química (60 kg/ha de N na forma de sulfato de amônio, 30 kg/ha de P2O5 na forma de superfosfato simples

Intrinsic immunogenicity of rapidly-degradable polymers evolves during degradation.

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Andorko, James I; Hess, Krystina L; Pineault, Kevin G; Jewell, Christopher M

2016-03-01

Recent studies reveal many biomaterial vaccine carriers are able to activate immunostimulatory pathways, even in the absence of other immune signals. How the changing properties of polymers during biodegradation impact this intrinsic immunogenicity is not well studied, yet this information could contribute to rational design of degradable vaccine carriers that help direct immune response. We use degradable poly(beta-amino esters) (PBAEs) to explore intrinsic immunogenicity as a function of the degree of polymer degradation and polymer form (e.g., soluble, particles). PBAE particles condensed by electrostatic interaction to mimic a common vaccine approach strongly activate dendritic cells, drive antigen presentation, and enhance T cell proliferation in the presence of antigen. Polymer molecular weight strongly influences these effects, with maximum stimulation at short degradation times--corresponding to high molecular weight--and waning levels as degradation continues. In contrast, free polymer is immunologically inert. In mice, PBAE particles increase the numbers and activation state of cells in lymph nodes. Mechanistic studies reveal that this evolving immunogenicity occurs as the physicochemical properties and concentration of particles change during polymer degradation. This work confirms the immunological profile of degradable, synthetic polymers can evolve over time and creates an opportunity to leverage this feature in new vaccines. Degradable polymers are increasingly important in vaccination, but how the inherent immunogenicity of polymers changes during degradation is poorly understood. Using common rapidly-degradable vaccine carriers, we show that the activation of immune cells--even in the absence of other adjuvants--depends on polymer form (e.g., free, particulate) and the extent of degradation. These changing characteristics alter the physicochemical properties (e.g., charge, size, molecular weight) of polymer particles, driving changes in

Bacterial rhizosphere and endosphere populations associated with grasses and trees to be used for phytoremediation of crude oil contaminated soil.

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Fatima, Kaneez; Afzal, Muhammad; Imran, Asma; Khan, Qaiser M

2015-03-01

Different grasses and trees were tested for their growth in a crude oil contaminated soil. Three grasses, Lolium perenne, Leptochloa fusca, Brachiaria mutica, and two trees, Lecucaena leucocephala and Acacia ampliceps, were selected to investigate the diversity of hydrocarbon-degrading rhizospheric and endophytic bacteria. We found a higher number of hydrocarbon degrading bacteria associated with grasses than trees and that the endophytic bacteria were taxonomically different from rhizosphere associated bacteria showing their spatial distribution with reference to plant compartment as well as genotype. The rhizospheric soil yielded 22 (59.45 %), root interior yielded 9 (24.32 %) and shoot interior yielded 6 (16.21 %) hydrocarbon-degrading bacteria. These bacteria possessed genes encoding alkane hydroxylase and showed multiple plant growth-promoting activities. Bacillus (48.64 %) and Acinetobacter (18.91 %) were dominant genera found in this study. At 2 % crude oil concentration, all bacterial isolates exhibited 25 %-78 % oil degradation and Acinetobacter sp. strain BRSI56 degraded maximum. Our study suggests that for practical application, support of potential bacteria combined with the grasses is more effective approach than trees to remediate oil contaminated soils.

Soil, water, and nutrient losses from management alternatives for degraded pasture in Brazilian Atlantic Rainforest biome.

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Rocha Junior, Paulo Roberto da; Andrade, Felipe Vaz; Mendonça, Eduardo de Sá; Donagemma, Guilherme Kangussú; Fernandes, Raphael Bragança Alves; Bhattharai, Rabin; Kalita, Prasanta Kumar

2017-04-01

The objective of this study was to evaluate sediment, water and nutrient losses from different pasture managements in the Atlantic Rainforest biome. A field study was carried out in Alegre Espiríto Santo, Brazil, on a Xanthic Ferralsol cultivated with braquiaria (Brachiaria brizantha). The six pasture managements studied were: control (CON), chisel (CHI), fertilizer (FER), burned (BUR), plowing and harrowing (PH), and integrated crop-livestock (iCL). Runoff and sediment samples were collected and analyzed for calcium (Ca), magnesium (Mg), potassium (K), phosphorus (P) and organic carbon contents. Soil physical attributes and above and below biomass were also evaluated. The results indicated that higher water loss was observed for iCL (129.90mm) and CON (123.25mm) managements, and the sediment losses were higher for CON (10.24tha -1 ) and BUR (5.20tha -1 ) managements when compared to the other managements. Majority of the nutrients losses occurred in dissolved fraction (99% of Ca, 99% of Mg, 96% of K, and 65% of P), whereas a significant fraction of organic carbon (80%) loss occurred in a particulate form. Except for P, other nutrients (Ca, Mg and K) and organic carbon losses were higher in coarse sediment compared to fine sediment. The greater losses of sediment, organic carbon, and nutrients were observed for CON followed by BUR management (plosses from various practices, to reduce pasture degradation, farmers should adopt edaphic practices by applying lime and fertilize to improve pasture growth and soil cover, and reducing soil erosion in the hilly Brazilian Atlantic Rainforest biome. Copyright © 2016. Published by Elsevier B.V.

Effects of inclusion levels of Indigofera sp. on feed intake, digestibility and body weight gain in kids fed Brachiaria ruziziensis.

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Andi Tarigan

2011-03-01

Full Text Available Twenty weaned male goats (F1 of Boer x Kacang with initial weight of 9 to 12 kg and ages ranging between 3.0 and 4.0 months were used in a study to evaluate the increasing inclusion of Indigofera sp foliage as a source of protein in diets based on chopped Brachiaria ruziziensis for growing goats. Five goats were allocated to one of four treatments in a randomised block design. The diet treatments were: T0 (control diets: B. ruziziensis (100%, T1 (85% B. ruziziensis + 15% Indigofera sp., T2 (70% B. ruziziensis + 30% Indigofera sp. T3 (55% B. ruziziensis + 45% Indigofera sp. all on DM basis. Feed (DM was offered daily at 3.5% BW. The content of CP in Indigofera sp is relatively high (258 g/kg DM, while the NDF (350.7 g/kg DM and ADF (232.2 g/ kg DM concentrations were low. The content of secondary compounds such as total phenol (8.9 g/kg DM, total tannin (0.8 g/kg DM and condensed tannin (0,5 g/kg DM were considerably low. The inclusion of Indigofera sp foliage in diets increased (P 0.05 among the T0,T1 and T2 diets and ranged from 0.08 to 0.09. It is concluded that the foliage of Indigofera sp could be used as feed supplement to supply proteins with low tannin contents. In a grass-based diets Indigofera sp colud be used at the level of 30 to 45% (DM for growing kids.

Quimio e termoterapia em sementes e aplicação de fungicidas em Brachiaria brizantha como estratégias no manejo do carvão Chemical and thermal therapy in seeds and application of fungicides in Brachiaria brizantha as strategies for managing smut

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Carlos Eduardo Marchi

2008-12-01

Full Text Available Objetivou-se estudar os potenciais dos tratamentos térmico e químico em sementes de Brachiaria brizantha cv. Piatã, preconizados como eficientes na superação da dormência física das mesmas, na redução do inóculo de carvão (Ustilago operta. Amostras de sementes foram expostas ao ácido sulfúrico por tempo variando de 0 a 10 min, ou imersas em água à temperatura variável (27 a 60 ºC por 5 ou 10 min. Avaliaram-se os efeitos dos tratamentos no número de teliósporos de U. operta remanescentes e na freqüência de germinação das sementes tratadas. À medida que se prolongou a escarificação química das sementes se evidenciou decréscimo do inóculo de carvão. Menor número de teliósporos foi observado nas sementes submetidas à quimioterapia por 10 min. Em geral, a exposição das sementes ao H2SO4 não levou ao decréscimo da capacidade germinativa das mesmas. Os resultados da termoterapia não foram tão evidentes como os observados para a quimioterapia, sejam na redução do número de teliósporos ou na superação da dormência. É provável que o tempo de exposição das sementes não tenha sido o suficiente. Paralelamente, verificou-se a eficiência da aplicação de fungicidas na parte aérea das plantas no controle da incidência do carvão. Foram testados os fungicidas: 1 - tiofanato metílico + chlorothalonil; 2 - mancozeb; 3 - tebuconazole; 4 - triadimenol; 5 - azoxystrobin + cyproconazole; 6 - pyraclostrobin + epoxyconazole; 7 - trifloxystrobin + cyproconazole; 8 - carboxin + thiram; 9 - tiofanato metílico + flutriafol; 10 - carbendazin, e 11 - difenoconazole. Mesmo com a ocorrência de baixa incidência de carvão na área experimental (máximo de 15%, observaram-se diferenças entre os fungicidas quanto ao controle da doença. O fungicida tebuconazole e as formulações pyraclostrobin + epoxyconazole e trifloxystrobin + cyproconazole foram os mais promissores.This work investigated the potentials of the thermal

Atividade microbiana e produção de milho (Zea mays e de Brachiaria brizantha sob diferentes métodos de controle de plantas daninhas Microbial activity and production of corn (Zea mays and Brachiaria brizantha under different methods of weed control

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A. Jakelaitis

2007-03-01

Full Text Available Avaliaram-se nesta pesquisa os efeitos dos herbicidas atrazine + nicosulfuron aplicados no consórcio entre milho a Brachiaria brizantha sobre a atividade microbiana do solo e a produtividade de ambas as espécies consorciadas. Os tratamentos constituíram-se do consórcio entre o milho e a forrageira B. brizantha, tratado com os herbicidas atrazine (1.500 g ha-1 ou a mistura deste com nicosulfuron (0, 4 e 32 g ha-1, e de duas testemunhas, representadas pelo consórcio capinado e sem capina. Os herbicidas foram aplicados 30 dias após a emergência (DAE do milho. Utilizou-se o delineamento em blocos casualizados, com quatro repetições. Foram avaliados a respiração, a biomassa microbiana (BM e o quociente metabólico (qCO2 de amostras de solo coletadas aos sete dias após a aplicação dos herbicidas (DAA, no florescimento e em pré-colheita do milho. Amostras de solo não tratadas foram coletadas a campo e tratadas com herbicidas atrazine (1.500 g ha-1 + nicosulfuron (0, 2, 4, 8, 16 e 32 g ha-1 em laboratório, onde se determinaram também a respiração, a BM e o qCO2. Em pré-colheita do milho, avaliaram-se as massas secas das plantas daninhas e da forrageira e o rendimento de grãos de milho. Observou-se que os métodos de controle não influenciaram a respiração, a BM e o qCO2 no solo nas três épocas avaliadas em campo e nas amostras de solo tratadas em laboratório. Todavia, em campo, verificou-se maior BM por ocasião do florescimento e maior qCO2 após a aplicação dos herbicidas, aos 7 DAA. Maior produção de massa seca de plantas daninhas foi observada nas parcelas não-capinadas e naquelas tratadas somente com atrazine. O rendimento forrageiro de B. brizantha foi superior no consórcio capinado, enquanto o rendimento de grãos de milho foi superior tanto no consórcio capinado quanto nas parcelas tratadas com nicosulfuron.This study aimed to evaluate the effects of atrazine + nicosulfuron on soil microbial activity and

ENHANCEMENT OF RESISTANCE TO OXIDATIVE DEGRADATION OF NATURAL RUBBER THROUGH LATEX DEGRADATION

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无

1998-01-01

A fully characterised natural rubber latex was subjected to mechanical degradation by stirring at intervals. The resistance to oxidative degradation of the different samples were studied by measuring the Plasticity retention indices (PRI).The results show that there is an enhancement of the PRI from 57% for the undegraded rubber to 79% for the one-hour degraded sample. Further degradation resulted in decrease of PRI as time of degradation increased. Therefore, the one-hour degraded sample is a special rubber with high oxidation resistance which is of great importance in engineering.

Banco de sementes como indicador de restauração de uma área degradada por mineração de caulim em Brás Pires, MG Seed bank as indicator of restoration of a kaolin mining - degraded area in Brás Pires, MG

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Sebastião Venâncio Martins

2008-12-01

Full Text Available Este estudo teve como objetivo caracterizar o banco de sementes sob vegetação secundária em uma área degradada por mineração de caulim em Brás Pires, MG. Foram coletadas 40 amostras de solo de 0,5 x 0,5 m até a profundidade de 5,0 cm. As amostras foram mantidas em viveiro por quatro meses, sendo metade em sombreamento de 11,5% (luz e metade em sombreamento de 60% (sombra. A germinação das sementes foi comparada nas duas condições de sombra (11,5% e 60%, utilizando-se o teste t para amostras independentes. Foram amostradas 36 espécies pertencentes a 17 famílias botânicas. As famílias com maior riqueza específica foram Asteraceae, com nove espécies, Rubiaceae com cinco e Poaceae com quatro. A maioria das espécies (66,7% e dos indivíduos (82,2% amostrados no banco foi de herbácea. As espécies com maior número de indivíduos germinados do banco foram as herbáceas Urochloa decumbens (Stapf R.D. Webster, Cenchrus sp. e Eragrostis sp. e a arbustiva Leandra niangaeformis Cogn. Entre as arbóreas, destacaram-se em número de indivíduos Luehea grandiflora Mart. e Trema micranta (L. Blume. A maior densidade de ervas daninhas oriundas de áreas antropizadas do entorno indicou baixa resiliência da vegetação presente na área degradada em caso de ocorrer alguma perturbação severa.This study aimed to characterize the soil seed bank under secondary vegetation in an area degraded by kaolin mining in Brás Pires, MG, Brazil. Forty soil samples of 0.5 x 0.5 m were collected to the depth of 5.0 cm. The soil samples were maintained in nursery for four months, half in shading of 11.5% (light, and half in shading of 60% (shade. Seed germination was compared under the two shade conditions (11.5% and 60%, utilizing the t test for independent samples. Thirty-six species belonging to 17 botanical families were sampled. The families with the largest number of species were Asteraceae with 9, Rubiaceae with 5, and Poaceae with 4. Most of the

Testing and validation of methods for the diagnosis and recomendation integrated system for Signal grass Calibração do modelo e validação do sistema integrado de diagnose e recomendação para o capim - branquiária

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Cristiane Prezotto Silveira

2005-12-01

Full Text Available The Diagnosis and Recommendation Integrated System (DRIS allows the interpretation of results of leaf analysis through relationships among nutrients, instead of the absolute and isolated concentration of each one, as it is used by the criterion of sufficiency range. The objective was to evaluate three procedures of calculation of DRIS indices, and to verify the efficiency of DRIS as interpretation method for the results of Brachiaria decumbens (Signal grass. The study was developed with the results of six experiments carried out in a greenhouse at Piracicaba, SP, with nutrient solution. Concentrations of N, P, K, Ca, Mg, S, Cu, Fe, Mn, and Zn were used in the samples of recently expanded leaf laminae of the grass. The validation of the DRIS method used results from an experiment with nitrogen and sulfur rates applied to the same grass from the Mundo Novo farm, Brotas, SP. DRIS indices were calculated according to two criteria to choose the ratio order of nutrients (F value and R value and three ways to calculate the nutrient functions (methods of Beaufils, Jones, and Elwali & Gascho. Nutritional Balance Index (NBI, calculated according to the generated norms, presented negative and significant correlation coefficients with the productivity in the combinations of methods tested and DRIS methods proposed by Beaufils, Jones and Elwali & Gascho were efficient in detecting concentrations that show nutrients deficiency or excess.O Sistema Integrado de Diagnose e Recomendação (DRIS permite a interpretação dos resultados de análise foliar, utilizando relações entre nutrientes, ao invés da concentração absoluta e isolada de cada um deles, utilizada pelo critério de faixa de suficiência. Objetivou-se avaliar três procedimentos de cálculo dos índices DRIS, bem como verificar a eficiência do DRIS como método de interpretação de resultados de análises de folhas da Brachiaria decumbens (capim-Braquiária. O estudo foi desenvolvido com os

Caracterização das fibras musculares do músculo Semitendinosus de bezerros mestiços Angus-Nelore recebendo somatotropina bovina recombinante (rbST até a desmama Characterization of Semitendinosus muscle fibers in pre-weaning Angus-Nellore crossbred calves receiving recombinant bovine somatotropin (rbST

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Rafael da Costa Cervieri

2005-06-01

Full Text Available Objetivando-se estudar o efeito da somatotropina bovina recombinante (rbST sobre a freqüência de distribuição e o diâmetro das fibras musculares do músculo Semitendinosus, 36 bezerros mestiços ½Angus-Nelore, com idade inicial de 63 ± 17 dias e pesando 76,8 ± 14,7 kg, criados em pastagem de Brachiaria decumbens e suplementados em creep feeding, foram submetidos a dois tratamentos até a desmama (217 dias: 18 bezerros receberam 1,4 mg/kg de rbST (Boostin® a cada 14 dias e 18 receberam solução salina (controle. As amostras de músculo foram coletadas aos 117 (biópsia e aos 217 dias de idade, quando foram abatidos cinco animais por tratamento. Os animais suplementados apresentaram maior diâmetro para as fibras do tipo glicolítica de contração rápida (FG aos 117 dias e tendência de aumento aos 217 dias e não diferiram em relação ao grupo controle quanto ao diâmetro das fibras oxidativas-glicolíticas de contração rápida (FOG e oxidativas de contração lenta (SO e à frequência de FG, FOG e SO aos 117 e 217 dias de idade. Independentemente da aplicação de rbST, houve significativo aumento do diâmetro das fibras SO e FOG, tendência de aumento de diâmetro das fibras FG, maior frequência de SO e redução da frequência de FG entre 117 e 217 dias de idade. A utilização de somatotropina exógena possibilitou maior hipertrofia das fibras musculares brancas de contração rápida em bezerros suplementados em creep feeding durante a fase de cria, sem interferir na frequência de distribuição dos tipos de fibras no músculo Semitendinosus.The objective of this experiment was to study the effect of the recombinant bovine somatotropin (rbST on the percentage distribution and diameter of semitendinosus muscle fibers. Thirty-six ½ Angus-Nellore crossbred bull calves, 63 ± 17 days old and weighting 76.8 ± 14.7 kg, raised in Brachiaria decumbens pastures and creep fed, were assigned to one of two treatments until weaning

Níveis de proteína em suplementos para terminação de bovinos em pastejo durante o período de transição seca/águas: consumo voluntário e trânsito de partículas Effects of feeding different protein levels of supplements to finishing cattle in pasture during the dry to rainy transition season on voluntary intake and passage of particles

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Edenio Detmann

2005-08-01

Full Text Available Avaliaram-se o consumo e os parâmetros da cinética de trânsito de partículas em bovinos suplementados durante a fase de transição entre os períodos seco e chuvoso. Foram utilizados cinco novilhos Holandês x Zebu com idade e peso médios iniciais de 24 meses e 304 kg, respectivamente, manejados em cinco piquetes de Brachiaria decumbens (0,34 ha. Foram fornecidos suplementos (4 kg/animal/dia, constituídos por fubá de milho, grão de soja integral, uréia, sulfato de amônia e mistura mineral, formulados para apresentarem níveis de 12, 16, 20 e 24% de proteína bruta (PB, com base na matéria natural. O experimento foi conduzido em quatro períodos experimentais de 21 dias e analisado por delineamento em quadrado latino 4 x 4. O quinto animal, mantido sem suplementação (controle, foi utilizado como medida de comparação descritiva. A forragem selecionada pelos animais apresentou teores médios de PB e fibra em detergente neutro (FDN de 109,9 e 564,4 g/kg de matéria seca (MS, respectivamente. A variação do nível de PB dos suplementos não alterou os consumos de MS, de matéria orgânica e de FDN. O fornecimento de suplementos reduziu o consumo de pastagem e ampliou o consumo de MS total em relação ao controle, com coeficiente médio de substituição de 0,41. O nível de PB dos suplementos não afetou a taxa de passagem ruminal das partículas, cujo valor médio (0,034 h-1, foi superior ao observado no controle (0,029 h-1.The objective of this trial was to evaluate the voluntary intake and ruminal passage of particles in supplemented finishing cattle during the drought to rainy transition season. Five Holstein x Zebu steers averaging 304 kg of live weight and 24 months of age located in five paddocks (0.34 ha each of Brachiaria decumbens were used in this trial. The supplements fed (4 kg/animal/day contained ground corn, whole soybean, urea, ammonium sulfate, and minerals and were formulated to yield, on as-fed basis, 12, 16, 20

Young calves production in native, mixed or cultivated pastures in the Pantanal, Mato Grosso do Sul, Brazil Produção de bezerros jovens em pastagens nativas, mistas ou cultivadas no Pantanal Sul Mato-Grossense

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Alexandre Menezes Dias

2008-09-01

Full Text Available The productive performance of 8, 9 and 10 month old calves raised, in pastures in the sub-area Nhecolândia.,was evaluated, in Pantanal, Mato Grosso do Sul, Brazil, for young calves slaughter. Fifty four calves were used, 27 males and 27 females in a randomized block, with a 3x3 factorial design (three pastures and three slaughter ages. The pastures were 1-native grass pasture, composed by Axonopus purpusii, Andropogon bicornis and Elyonurus muticus, 2-cultivated pasture, composed by Brachiaria decumbens and B. humidicula, and 3-mixed, composed by native grass and cultivated pasture. There was significant interaction (P<.05 between slaughter age and pasture type. The animals with 8 and 10 months old that grew on mixed pastures presented higher slaughter weight (SW, higher average daily gain (ADG and carcass weight (CW, compared to animals in native or cultivated pastures. Animals in mixed pasture and slaughtered with 8 months old presented ADG of 0.83 kg/day, while animals maintained in native and cultivated pastures presented 0.65 and 0.59kg/day, respectively. For animals slaughtered with 9 months old, ADG were 0.55; 0.61 and 0.64 kg/day; and, for those slaughtered with 10 months, the averages were 0.48; 0.73 and 0.51kg/day, respectively, for native, mixed and cultivated pastures. The carcass yield was not influenced by slaughter age, for native and mixed pastures. There was not significant sex effect for any of the evaluated variables. The slaughter of male or female calves, raised in mixed or cultivated pastures, between 8 and 10 months old, is recommended for veal production.Avaliou-se o desempenho produtivo de bezerros abatidos aos oito, nove e dez meses de idade, criados em pastagens no Pantanal Sul mato-grossense, visando o abate de bezerros jovens. Utilizaram-se 54 bezerros, sendo 27 machos e 27 fêmeas provenientes da sub-região pantaneira Nhecolândia. O delineamento experimental foi em blocos casualizados por sexo, em esquema

Macromineral requirements by beef cattle under pasture supplementation Exigências de macrominerais de bovinos de corte sob suplementação a pasto

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Maykel Franklin Lima Sales

2011-02-01

Full Text Available The objective of this work was to determine macromineral requirements by Zebu steers grazing Brachiaria decumbens supplemented with concentrate. It was used 24 non-castrated steers, at an average age of 7 months and at initial average weight 180 kg. Eight control animals were slaughtered for determining initial body composition. The 16 remaining animals were divided in four four-animal plots, in a complete random design. Each plot received mineral mixture or supplements at the levels 0.75; 1.50 or 2.25 kg/animal/day. The right half-carcass of eight animals, two per group, was dissected in muscle, fat and bones and all body constituents were weighted for determination of empty body weight and body composition. Net requirements of calcium and phosphorus for an animal at 400 kg body weight were 11.13 g and 5.40 g, respectively. To estimate dietary requirements of maintenance and after, sum them to dietary requirements for gain in order to obtain total dietary requirements, it was adopted endogenous losses and bioavailability present in literature for each mineral macroelement. Total dietary requirement for calcium, phosphorus, magnesium, sodium and potassium for a 400-kg BW animal with 1.0-kg daily weight gain were 34.59; 17.36; 7.82; 5.19 and 41.11 g/day, respectively. Macromineral requirements by beef cattle under pasture supplementation are similar to those recommended by BR-Corte for beef cattle in feedlots.Objetivou-se determinar as exigências de macrominerais de novilhos zebuínos em pastagem de Brachiaria decumbens suplementada com concentrado. Foram utilizados 24 novilhos, não-castrados, com idade e pesos médio iniciais de 7 meses e 180 kg. Foram abatidos oito animais-referência para determinação da composição corporal inicial. Os 16 animais restantes foram divididos em quatro lotes de quatro animais, em delineamento inteiramente casualizado. Cada lote recebeu mistura mineral ou suplementos nos níveis de 0,75; 1,50 ou 2,25 kg

Correlações entre componentes anatômicos, químicos e digestibilidade in vitro da matéria seca de gramíneas forrageiras Chemical and anatomical traits, and in vitro dry matter digestibility correlations in forage grasses

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Domingos Sávio Campos Paciullo

2001-06-01

Full Text Available Lâminas foliares e segmentos de colmo das gramíneas forrageiras capim-braquiária (Brachiaria decumbens, capim-gordura (Melinis minutiflora e capim-bermuda Tifton 85 (Cynodon sp foram amostradas em dois níveis de inserção no perfilho (inferior e superior, em duas idades (momento da exposição da lígula da folha e 20 dias após e em duas estações de crescimento (verão e outono. Amostras dos segmentos de colmo e lâminas foliares foram submetidas à determinação de sua composição química, composição anatômica e digestibilidade in vitro. Após obtenção dos dados, foram estabelecidas as correlações entre os componentes químicos e anatômicos e entre estes e a DIVMS, na lâmina, no colmo e no agrupamento dos dados das duas frações. A espessura da parede celular foi a característica anatômica a se correlacionar mais fortemente com todos os componentes químicos, independente da fração considerada. Suas correlações foram positivas com os teores de fibra em detergente neutro, fibra em detergente ácido e lignina e negativa com os de proteína bruta. A proporção de mesofilo se correlacionou positivamente com os teores de proteína bruta e negativamente com os de fibra em detergente ácido, enquanto a proporção de esclerênquima apresentou correlação positiva com os teores de fibra em detergente neutro. Os componentes químicos se correlacionaram fortemente entre si e com a DIVMS. Entre as características anatômicas, somente a espessura da parede celular mostrou correlação significativa com a DIVMS, independente da fração. O mesofilo se correlacionou positivamente e o xilema negativamente com a DIVMS, respectivamente, na lâmina e no colmo.Leaf blades and stem segments at two stages of development (day of leaf ligule exposure and 20 days thereafter and two insertion levels on tillers (lower and upper of signalgrass (Brachiaria decumbens, molassesgrass (Melinis minutiflora and tifton 85 bermudagrass (Cynodon sp

Desempenho de novilhos nelore suplementados em pasto durante época das águas Performance of crossbreed nelore bullock grazing supplemented during the raining seazon

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Wilker Dias Lima

2004-02-01

Full Text Available A procura por alimentos e derivados que não sejam utilizados na dieta humana ou na alimentação de animais monogástricos, juntamente com formas de suplementação, são aspectos importantes na busca de fontes alternativas para alimentação de ruminantes e redução no tempo de abate. Com este trabalho teve-se como objetivo avaliar o efeito de níveis crescentes de concentrado na engorda de novilhos nelore suplementados em pasto durante o período das águas. O experimento foi realizado na Fazenda Vitorinha, de propriedade da Fundação de Apoio ao Ensino, Pesquisa e Extensão/FAEPE, ligada à Universidade Federal de Lavras/UFLA, em Lavras, região sul do Estado de Minas Gerais, entre os meses de janeiro a maio de 2001. Foram utilizados 24 animais mestiços nelores, machos, inteiros, com idade média de 17 meses e peso vivo médio de 308,0 kg. Durante o período experimental, os animais foram alojados em uma pastagem de Brachiaria decumbens, com área de 11,2 ha, com disponibilidade média de 5400 kg MS/ha no início do período. Os tratamentos constituíram-se de níveis crescentes de concentrado, calculados como percentual do peso vivo: T1- 0%; T2- 0,15%; T3- 0,30%; T4- 0,45%. O experimento foi delineado em blocos casualizados, com peso vivo inicial como fator de blocagem, sendo 6 blocos e 4 tratamentos, totalizando 24 parcelas experimentais. Para análise dos dados, utilizou-se o software estatístico SISVAR (Sistema de Análise de Variância de Dados Balanceados. Não houve diferença significativa para ganho de peso diário (PThe demand for foods and its derivates that would not be used in the human diet or in the monogastric animals diet in addition with supplement forms are important aspects in the search for alternative sources for ruminant nutrition and reduction in the slaughtered time. This work had as objective to evaluate growing levels of concentrate in the fattening of nelore bullock gazing supplemented during the raining

Efeitos dos períodos de competição do mato na cultura do amendoim: II. Safra das águas Effects of weed competition periods on peanut: II. Wet season crop

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EDISON MARTINS PAULO

2001-01-01

Full Text Available O presente trabalho foi realizado na safra das águas de 1989, no Núcleo de Agronomia da Alta Paulista, em Adamantina (SP para estudar o efeito de diferentes períodos de competição do mato no amendoim. Adotou-se o delineamento estatístico de blocos ao acaso, com quatro repetições e 22 tratamentos. Os tratamentos resultaram da combinação da presença e da ausência do mato a partir do início da cultura, com as seguintes épocas de remoção da flora infestante: 0, 10, 20, 30, 40, 50, 60, 70, 80, 90 e 100 dias após a semeadura. As parcelas foram constituídas por quatro linhas de amendoim, perfazendo 6 m² de área útil. As principais plantas daninhas encontradas na área experimental foram: Cyperus lanceolatus Poir, Commelina benghalensis L., Brachiaria decumbens Stapf., Amaranthus viridis L., Eleusine indica (L. Gaertn., Portulaca oleracea L., Digitaria horizontalis Willd. e Solanum americanum Mill. A convivência do mato diminuiu a produção de vagens, de grãos e a população do amendoim na colheita. Não se observou efeito do mato sobre o rendimento de grãos e sobre a matéria seca acumulada pela parte aérea do amendoim. Capinas aplicadas aos 13 e 67 dias após a semeadura, respectivamente para os sistemas sem e com mato a partir da semeadura, foram suficientes para a obtenção de produção de vagens de amendoim estatisticamente igual à obtida pela cultura mantida sem competição, durante todo o ciclo. Os componentes da produção do amendoim foram favorecidos com a aplicação do sistema sem mato, a partir do início da cultura.The present research was carried out at the Núcleo de Agronomia da Alta Paulista, in Adamantina, State of Sao Paulo, Brazil, to study the effects of different periods of weed competition with peanut.The treatments were all possible combinations among the presence/absence of weeds (at the sowing time and the following periods of weed removal: 0, 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100 days

Seletividade e controle de plantas daninhas com oxyfluorfen e sulfentrazone na implantação de lavoura de café Weed selectivity and control with oxyfluorfen and sulfentrazone in young arabica coffee plantations

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C.E.O. Magalhães

2012-09-01

Full Text Available Este trabalho teve por objetivo avaliar a seletividade do oxyfluorfen e do sulfentrazone e o controle de plantas daninhas em diferentes épocas após o transplantio das mudas de café no campo. Foram realizados três ensaios no delineamento experimental de blocos casualizados com dez tratamentos e quatro repetições. No ensaio 1, aos 30 dias após o transplantio (DAT e, no ensaio 2, aos 90 DAT, testaram-se duas doses de oxyfluorfen (0,36 e 0,72 kg i.a. ha-1 e de sulfentrazone (0,4 e 0,6 kg i.a. ha-1, em jato dirigido ao solo (com proteção das mudas e em área total. No ensaio 3, os mesmos herbicidas e doses foram aplicados, porém aos 300 DAT e apenas em aplicação dirigida, testando-se duas pontas de pulverização de diferentes potenciais de deriva. Em todos os ensaios, acrescentaram-se as testemunhas capinada e sem capina. A entrelinha foi manejada com roçada. Foram identificadas as espécies de plantas daninhas e suas densidades. A eficácia dos herbicidas e suas seletividades também foram avaliadas. A principal planta daninha que ocorreu na área experimental foi Brachiaria decumbens. Sintomas visuais de toxicidade foram observados apenas quando os herbicidas foram aplicados em área total (ensaios 1 e 2, independentemente da dose e época de aplicação. No ensaio 3, independentemente do herbicida, da dose e da ponta utilizada, não houve sintomas visuais de toxicidade, nem redução no crescimento das plantas, em função da aplicação dirigida. Em todas as épocas o controle de plantas daninhas foi eficiente, porém a seletividade só foi alcançada na aplicação dirigida, para ambos os herbicidas.This study aimed to evaluate oxyfluorfen and sulfentrazone selectivity and weed control in young coffee plantations (Coffea arabica cv. Red Catuaí. Three trials were conducted in a randomized complete block design, with 10 treatments and four replicates. In the first and second trials, at 30 and 90 days after transplanting (DAT

Intervalo hídrico ótimo na avaliação de sistemas de pastejo contínuo e rotacionado Least limiting water range in the evaluation of continuous and short-duration grazing systems

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T. P. Leão

2004-06-01

Full Text Available A qualidade física do solo sob sistemas de pastejo contínuo e rotacionado foi avaliada pelo Intervalo Hídrico Ótimo (IHO. A amostragem foi realizada na área experimental da Embrapa Gado de Corte. Foi estudado um Latossolo Vermelho distrófico. Foram avaliados quatro piquetes, sendo dois no sistema de pastejo contínuo e dois no sistema de pastejo rotacionado. No sistema de pastejo contínuo, implementado com a espécie Brachiaria decumbens cv. Basilisk, foram retiradas 30 amostras por piquete, não tendo um dos piquetes recebido adubação de manutenção (Cs, enquanto o outro havia recebido adubação bianual de manutenção (Cc. No sistema de pastejo rotacionado, implementado com a espécie Panicum maximum cv. Tanzânia, foram retiradas 30 amostras por piquete; em um dos piquetes, o resíduo pós-pastejo era mantido entre 2,0 e 2,5 t ha-1 de matéria seca total (MST (R1, enquanto no outro era mantido entre 3,0 e 3,5 t ha-1 MST (R2. As amostras foram submetidas a um gradiente de tensão de água e, posteriormente, utilizadas nas determinações da densidade do solo (Ds, resistência do solo à penetração (RP, umidade volumétrica (tetav e do IHO. O sistema de pastejo rotacionado apresentou piores condições físicas do solo para o crescimento vegetal, avaliadas pelo critério do IHO. Os maiores valores de Ds e menor IHO foram observados no R1, o que foi atribuído às taxas de lotação mais elevadas aplicadas neste piquete.Soil physical quality in continuous and short-duration rotational cattle grazing systems was evaluated using the Least Limiting Water Range (LLWR approach. Soil samples were collected on an experimental site at the Embrapa - Beef Cattle Research Center (Campo Grande, MS, Brazil. The studied soil was a Typic Acrudox. Four sampling sites were selected: two under a short-duration continuous grazing system and two under intensive short-duration rotational grazing system. Thirty soil cores were collected in each site

Características anatômicas e valor nutritivo de quatro gramíneas predominantes em pastagem natural de Viçosa, MG Anatomical evaluation and nutritive value of four prevailing forage grasses in natural pasture of Viçosa-MG

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Maristela de Oliveira Bauer

2008-01-01

Full Text Available Avaliou-se a influência das características anatômicas e dos sítios de lignificação dos tecidos sobre o valor nutritivo de lâminas foliares de quatro gramíneas coletadas nas estações chuvosa e seca. Amostras frescas das duas últimas lâminas foliares recém-expandidas, correspondentes à última e à penúltima posição no perfilho de capim-gordura (Melinis minutiflora Pal. De Beauv, capim-braquiária (Brachiaria decumbens Staph., capim-sapé (Imperata brasiliensis Trin. e capim-jaraguá (Hyparrhenia rufa (Nees Staph. foram avaliadas quanto às características anatômicas, segundo técnicas de microscopia de luz e varredura. Nessas amostras analisou-se a proporção de tecidos e de sítios de lignificação. Também foram determinadas as concentrações de fibra em detergente neutro (FDN, fibra em detergente ácido (FDA, lignina e celulose da parede celular, assim como a digestibilidade in vitro da matéria seca (DIVMS. Os dados foram analisados segundo delineamento inteiramente casualizado, com os tratamentos no esquema fatorial, com três repetições. Determinaram-se as correlações entre DIVMS, componentes químicos da parede celular e proporção de tecidos. Observou-se o mesmo padrão de proporção de tecidos e DIVMS no capim-gordura e no capim-braquiária, assim como nos capins sapé e jaraguá. A digestibilidade in vitro da matéria seca e os componentes da parede celular sofreram influência da estação, enquanto as características anatômicas não foram significativamente influenciadas por esse fator. Os capins gordura e braquiária caracterizaram-se por maiores proporções de bainha parenquimática do feixe e os capins sapé e jaraguá por maiores proporções de xilema e esclerênquima. Altos coeficientes negativos de correlação foram estabelecidos entre os coeficientes de digestibilidade e as proporções de xilema e esclerênquima, assim como com os teores de FDN, FDA e lignina das lâminas foliares.It was

Estabilidade de agregados de um latossolo vermelho tratado com cama de peru Aggregate stability of a Red Latosol amended with turkey litter

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Adriana Monteiro da Costa

2008-02-01

Full Text Available Recentemente, tem ocorrido um grande aumento na produção de aves, com destaque para a carne de peru, motivado pelo aumento das exportações e a conquista de novos mercados. Como conseqüência, tem sido gerada uma grande quantidade de resíduos orgânicos com potencial impacto sobre o ambiente. A cama de peru constitui-se no principal resíduo dessa atividade avícola, e uma das formas de sua utilização é a sua disposição em solos como condicionador de suas características físicas e químicas. Assim, objetivou-se com este trabalho avaliar o efeito da aplicação da cama de peru na estabilidade de agregados de um Latossolo Vermelho Distrófico típico, sob pastagem de Brachiaria decumbens, localizado em Uberlândia, no Triângulo Mineiro, Minas Gerais. A cama de peru foi aplicada nas dosagens de: 0 (controle, 1.200, 2.400 e 4.800 kg ha-1 e 2.400 kg ha-1 + adubação mineral (36 kg ha-1 N, 60 kg ha-1 K2O e 60 kg ha-1de P2O5. As aplicações foram realizadas em janeiro de 2004 e o solo amostrado em duas épocas distintas (60 e 210 dias após aplicação nas camadas de 0-20 e 20-40 cm para análise da estabilidade de agregados, avaliada pela percentagem total de agregados, percentagem de agregados maiores que 2mm, menores que 0,25mm e diâmetro médio geométrico (DMG. Não houve efeito das dosagens de cama de peru aplicadas na agregação do solo, entretanto, independentemente da dose aplicada houve um aumento na estabilidade de agregados, ao longo do tempo, notadamente na camada de 0-20 cm.Recently, there has been occurring a great increase in poultry production, especially in turkey's meat, motivated by the increase of exports and conquest of new markets. As a consequence, a great amount of organic residues has been generated, providing potential impact on the environment. Turkey litter is the main residue from such activity, and has been used as soil conditioner, intended to improve physical and chemical characteristics. Therefore, the

Degradação in vitro de tecidos da lâmina foliar e do colmo de gramíneas forrageiras tropicais, em função do estádio de desenvolvimento In vitro digestion of leaf blade and stem tissues of tropical forage grasses according to stages of development

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Domingos Sávio Campos Paciullo

2002-04-01

Full Text Available O experimento foi realizado com o objetivo de avaliar o efeito da idade sobre o potencial de degradação dos diferentes tecidos da lâmina foliar e do colmo de capim-braquiária (Brachiaria decumbens, capim-gordura (Melinis minutiflora e capim-tifton 85 (Cynodon sp. Foram amostradas a 7ª (capim-braquiária e capim-gordura e a 11ª (capim-tifton 85 lâminas foliares, no dia da exposição da lígula e 20 dias após. Por meio de observações ao microscópio foram estimadas a extensão da digestão in vitro dos tecidos da lâmina e do colmo e a redução na espessura da parede de células do esclerênquima do colmo. Lâminas foliares e segmentos de colmos jovens apresentaram maiores áreas digeridas. Permaneceram intactos os tecidos com células de parede espessada e lignificada, a bainha parenquimática dos feixes, o esclerênquima, o xilema e a epiderme do colmo. Tecidos com células de parede delgada, normalmente não-lignificada, o mesofilo, o floema e o parênquima, desapareceram completamente. O avanço na idade reduziu a digestão do mesofilo, em lâminas de capim-braquiária e capim-gordura, e do parênquima em colmos, principalmente de capim-gordura. A epiderme na lâmina foliar foi parcialmente digerida, independentemente da idade e da espécie. Embora aparentemente intactas, células esclerenquimáticas do colmo sofreram redução da espessura da parede com a incubação em líquido ruminal. A porcentagem de redução variou de 7 a 37% e a taxa de redução da espessura de 0,007 a 0,018 µm/h.A trial was carried out to evaluate the change in digestion of tropical grasses leaf and stem tissues with age. The grasses were signalgrass (Brachiaria decumbens, molassesgrass (Melinis minutiflora and Tifton 85 bermudagrass (Cynodon sp. The 7th leaf of signalgrass and molassesgrass and the 11th leaf of bermudagrass were sampled by the time of their complete expansion (ligule exposure and 20 days later. Segment of stem just below the sampled

A retrospective serologic survey of hantavirus infections in the county of Cássia dos Coqueiros, State of São Paulo, Brazil Inquérito sorológico retrospectivo das infecções por hantavirus no município de Cássia dos Coqueiros, Estado de São Paulo, Brasil

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Soraya Jabur Badra

2012-08-01

Full Text Available INTRODUCTION: In recent years, hantavirus infections producing severe diseases have obtained an increased attention from public health authorities from the countries of Eurasia to the Americas. Brazil has reported 1,300 cases of hantavirus cardiopulmonary syndrome (HCPS from 1993 to 2010, with about 80 of them occurring in the northeast of the State of São Paulo, with 48% fatality rate. Araraquara virus was the causative agent of HCPS in the region. Considering that hantaviruses causing human disease in the Americas were unknown until 1993, we have looked for hantavirus infections in the population of Cássia dos Coqueiros county, northeast of the State of São Paulo, Brazil, before this time. This county has about 2,800 inhabitants and an economy based on agriculture, including cultivation of Brachiaria decumbens grass. The grass seeds are an important rodent attraction, facilitating transmission of hantavirus to man. Four HCPS cases were reported so far in the county. METHODS: In this study, 1,876 sera collected from 1987 to 1990 were tested for IgG to hantavirus by IgG-ELISA, using the N recombinant protein of Araraquara virus as antigen. RESULTS: Positive results were observed in 89 (4.7% samples, which were all collected in 1987. The positivity among urban inhabitants was 5.3%, compared with 4.3% among those living in rural areas. CONCLUSIONS: Our results showed that hantavirus infections occurred in Cássia dos Coqueiros, completely unrecognized, even before hantaviruses were described in the Americas.INTRODUÇÃO: Infecções graves por hantavírus têm obtido crescente atenção das autoridades da saúde pública da Eurásia e Américas. De 1993 a 2010, o Brasil reportou 1.300 casos de síndrome pulmonar cardiovascular por hantavírus (SPCVH com, aproximadamente, 80 deles no nordeste do Estado de São Paulo com taxa de fatalidade de 48%. O vírus Araraquara é o agente etiológico da SPCVH nessa região. Considerando que nas Am

Avaliação nutricional, durante a amamentação, de tourinhos em pastejo recebendo suplementação proteica da amamentação à terminação Nutritional evaluation, during the nursing phase, of grazing young bulls that received supplementation with different protein profiles from nursing to finishing

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Henrique Jorge Fernandes

2012-02-01

Full Text Available O objetivo neste estudo foi avaliar as condições nutricionais de tourinhos em aleitamento, a pasto, recebendo suplementação com concentrados proteicos durante a época de transição águas-seca. Foram utilizados 52 bezerros mestiços com idade média inicial de 130 dias. Os animais foram distribuídos em quatro lotes, alojados em piquetes de Brachiaria decumbens Stapf junto com suas mães, onde receberam uma das quatro estratégias de suplementação: três suplementos concentrados, ou sal mineral (controle. Os suplementos concentrados diferiram quanto ao nível de proteína. Após 45 dias, realizou-se a avaliação nutricional dos animais, que incluiu a estimação do consumo e da digestão de nutrientes e das características do metabolismo proteico. A estimação do consumo e da digestibilidade foi feita utilizando-se os indicadores: LIPE®, dióxido de titânio e fibra em detergente neutro indigestível. Realizou-se ainda coleta de amostras de urina e de sangue. O efeito de suplementação e os efeitos linear e quadrático do nível de proteína no concentrado foram avaliados pela decomposição da soma de quadrados em contrastes ortogonais, adotando-se α = 0,10. O consumo de concentrado substituiu parte do pasto ingerido pelos bezerros e aumentou a ingestão de proteína, a digestibilidade da matéria seca e matéria orgânica, o teor de nutrientes digestíveis totais e a excreção de nitrogênio na urina. O nível de proteína no suplemento tem efeito linear positivo sobre a ingestão diária de proteína, a digestibilidade de todos os nutrientes e o teor de nutrientes digestíveis totais e efeito quadrático sobre a excreção de nitrogênio na forma de ureia na urina.The objective of this study was to evaluate the nutritional status of grazing nursing young bulls supplemented with concentrates with different protein levels during the rainy-dry season transition. Fifty two crossbred Nellore calves with initial mean age of 130 days

A thermo-degradable hydrogel with light-tunable degradation and drug release.

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Hu, Jingjing; Chen, Yihua; Li, Yunqi; Zhou, Zhengjie; Cheng, Yiyun

2017-01-01

The development of thermo-degradable hydrogels is of great importance in drug delivery. However, it still remains a huge challenge to prepare thermo-degradable hydrogels with inherent degradation, reproducible, repeated and tunable dosing. Here, we reported a thermo-degradable hydrogel that is rapidly degraded above 44 °C by a facile chemistry. Besides thermo-degradability, the hydrogel also undergoes rapid photolysis with ultraviolet light. By embedding photothermal nanoparticles or upconversion nanoparticles into the gel, it can release the entrapped cargoes such as dyes, enzymes and anticancer drugs in an on-demand and dose-tunable fashion upon near-infrared light exposure. The smart hydrogel works well both in vitro and in vivo without involving sophisticated syntheses, and is well suited for clinical cancer therapy due to the high transparency and non-invasiveness features of near-infrared light. Copyright © 2016 Elsevier Ltd. All rights reserved.

Organic matter degradation in Chilean sediments - following nature's own degradation experiment

DEFF Research Database (Denmark)

Langerhuus, Alice Thoft; Niggemann, Jutta; Lomstein, Bente Aagaard

ORGANIC MATTER DEGRADATION IN CHILEAN SEDIMENTS – FOLLOWING NATURE’S OWN DEGRADATION EXPERIMENT Degradation of sedimentary organic matter was studied at two stations from the shelf of the Chilean upwelling region. Sediment cores were taken at 1200 m and 800 m water depth and were 4.5 m and 7.5 m...... in length, respectively. The objective of this study was to assess the degradability of the organic matter from the sediment surface to the deep sediments. This was done by analysing amino acids (both L- and D-isomers) and amino sugars in the sediment cores, covering a timescale of 15.000 years. Diagenetic...... indicators (percentage of carbon and nitrogen present as amino acid carbon and nitrogen, the ratio between a protein precursor and its non-protein degradation product and the percentage of D-amino acids) revealed ongoing degradation in these sediments, indicating that microorganisms were still active in 15...

Stapf colhidas por varredura manual ou mecanizada Components of seed production of two cultivars of Brachiaria Componentes da produção e qualidade de sementes dos cultivares marandu e xaraés de Brachiaria brizantha (Hochst. ex A. Rich.

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Danilo Gusmão de Quadros

2012-10-01

Full Text Available The objective of this study was to evaluate the seed production compounds and productivity of seeds of cvs. Marandu and Xaraés of Brachiaria brizantha (Hochst. ex A. Rich. Stapf harvest by manual or mechanical sweeping. There was used completely randomized design, with 20 replications, quantifying reproductive tillers density, number of racemes/tiller, the length of basal raceme, number of spikelets / raceme, and the pure seed productivety/ha, using squares of 1m2 in the seed production field with 320 and 80 ha sowing with cvs. Xaraés and Marandu, respectively, in the Sagrillo Farmer, Barreiras, western Bahia State-Brazil, with samples occurring from May to Jun of 2008. The seeds harvest manually handle were analyzed in pureness, germination, and seedling vigor under three depths in sand box (1, 2 and, 4 cm. The data were statistically analyzed by ASSISTAT program, assuming as significative differences between averages when F values were lower than 0.05 by the test Tukey. The cv. Xaraés showed more reproductive tiller density (206/m2, higher number of racemes (7.25 and more length per raceme (15.8 cm than the cv. Marandu (100 tillers/m2, 6.80 racemes/tiller e 14.9 cm/raceme, respectively. However, the number of spikelets by raceme was the same (50.8 units. The pure seed productivity was higher in the cv. Xaraés (188 kg/ha than the cv. Marandu (154 kg/ha. Germination in sand was not different between cultivars, harvest method, or depth of seed. However, seedling development decreased with increase of seed depth from 1 and 2 cm to 4 cm. The cv. Xaraés was superior considering the seed production compounds, resulting in higher seed productivity, while quality did not differ between cultivars or harvest method. Objetivou-se com este trabalho avaliar os componentes da produção e a qualidade de sementes dos cvs. Marandu e Xaraés de Brachiaria brizantha (Hochst. ex A. Rich. Stapf nos cerrados baianos, colhida por varredura manual ou mecanizada

Desempenho reprodutivo de ovelhas mestiças da raça Santa Inês em Brachiaria humidícula e efeito do sexo no ganho de peso de cordeiros

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P.A. Oliveira

2014-02-01

Full Text Available Objetivou-se avaliar o desempenho reprodutivo de ovelhas deslanadas em função do manejo alimentar das crias e idade de desmame, além de mensurar o efeito do sexo no ganho de peso de cordeiros. Sessenta e quatro ovelhas mestiças da raça Santa Inês foram distribuídas em delineamento inteiramente ao acaso, em esquema fatorial 4 x 2 x 2 - quatro idades de desmame (56, 70, 84 e 98 dias, sexo e manejo alimentar das crias, cada tratamento com quatro repetições. As ovelhas foram manejadas com a cria ao pé, em 14 piquetes de 1,5 ou 2,0 hectares, formados com pastagem de Brachiaria humidícola. As crias nascidas de partos simples, filhos de reprodutores Santa Inês puros de origem (PO. Após o desmame de todos os grupos, sessenta e quatro cordeiros (32 machos e 32 fêmeas foram distribuídos ao acaso em baias individuais e confinados por 30 dias. A comparação dos parâmetros foi realizada pelo ajuste do modelo de regressão linear simples. Verificou-se vício de tempo longo do manejo alimentar das crias de + 3,7% (P<0,05 para o intervalo entre partos e de + 1,4% (P<0,05 para o período de serviço. Houve efeito linear crescente (P<0,05 da idade de desmame sobre o intervalo entre partos e período de serviço. Verificou-se vício de tempo longo do sexo das crias de + 2,0% (P<0,05 para o intervalo entre partos e de + 0,8% (P<0,05 para o período de serviço das ovelhas. Constatou-se vício de tempo longo do sexo de + 35,2% e + 36,9% (P<0,05, respectivamente, para o ganho de peso diário de cordeiros do nascimento ao desmame e pós desmame em confinamento. A suplementação das crias em alimentador privativo e a antecipação da idade de desmame reduzem o intervalo entre partos e período de serviço de ovelhas deslanadas em pastagem de Brachiaria humidícula. O sexo da cria é fonte de variação na análise da eficiência reprodutiva de matrizes ovinas e no ganho de peso de cordeiros mestiços da raça Santa Inês do nascimento ao desmame e ap

Degradation of microbial polyesters.

Science.gov (United States)

Tokiwa, Yutaka; Calabia, Buenaventurada P

2004-08-01

Microbial polyhydroxyalkanoates (PHAs), one of the largest groups of thermoplastic polyesters are receiving much attention as biodegradable substitutes for non-degradable plastics. Poly(D-3-hydroxybutyrate) (PHB) is the most ubiquitous and most intensively studied PHA. Microorganisms degrading these polyesters are widely distributed in various environments. Although various PHB-degrading microorganisms and PHB depolymerases have been studied and characterized, there are still many groups of microorganisms and enzymes with varying properties awaiting various applications. Distributions of PHB-degrading microorganisms, factors affecting the biodegradability of PHB, and microbial and enzymatic degradation of PHB are discussed in this review. We also propose an application of a new isolated, thermophilic PHB-degrading microorganism, Streptomyces strain MG, for producing pure monomers of PHA and useful chemicals, including D-3-hydroxycarboxylic acids such as D-3-hydroxybutyric acid, by enzymatic degradation of PHB.

Fractions of carbohydrates and of nitrogenous compounds of tropical grasses at different cutting ages Fracionamento de carboidratos e compostos nitrogenados de gramíneas tropicais em diferentes idades de corte

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Patrícia Regina de Souza Siqueira Campos

2010-07-01

Full Text Available It was evaluated by the Cornell System carbohidrates fractions and nitrogenous compounds of the following grasses at the cutting ages of 14, 28, 42, and 56 days: nilo grass (Acroceras macrum, angola grass (Brachiaria purpurascens, aleman grass (Echinochloa polystachya, limpo grass (Hemarthria altíssima, setaria grass (Setaria anceps, tanner grass (Brachiaria arrecta, and tifton-85 grass (Cynodon spp. The experiment was carried out in a complete randomized block design, in a split plot arrangement in a way that the grasses were evaluated in the plots and the ages of cut in the split-plots. The age of cutting had an effect on the composition of the studied grasses. In most of the grasses, total carbohydrate levels, non-fibrous carbohydrates and A+B1 fraction carbohydrates increased linearly according to the age of cutting. The potentially degradable fraction of carbohydrates (fraction B2 showed a quadratic behavior according to the cutting ages for all grasses. The C fraction of the carbohydrates in tifton-85 grass linearly increased with the age but it did not increase significantly for the other grasses. In setaria grass, the intermediate levels of B2 and B3 nitrogenous fractions were high, which might represent a potential source of protein for ruminal degradation and for the small intestine. Except for setaria grass, all studied grasses show similar values of the A, B1, B2 and B3 nitrogenous fractions.Avaliaram-se pelo Sistema Cornell as frações de carboidratos e os compostos nitrogenados dos capins acroceres (Acroceras macrum, angola, (Brachiaria purpurascens, canarana (Echinochloa polystachya, hemarthria (Hemarthria altíssima, setária (Setaria anceps, tanner grass (Brachiaria arrecta e tifton 85 (Cynodon spp nas idades de corte de 14, 28, 42 e 56 dias. O experimento foi conduzido em blocos ao acaso em esquema de parcelas subdivididas de modo que as gramíneas foram avaliadas nas parcelas e as idades de corte, nas subparcelas. Houve

Polycyclic aromatic hydrocarbons degradation by marine-derived basidiomycetes: optimization of the degradation process.

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Vieira, Gabriela A L; Magrini, Mariana Juventina; Bonugli-Santos, Rafaella C; Rodrigues, Marili V N; Sette, Lara D

2018-05-03

Pyrene and benzo[a]pyrene (BaP) are high molecular weight polycyclic aromatic hydrocarbons (PAHs) recalcitrant to microbial attack. Although studies related to the microbial degradation of PAHs have been carried out in the last decades, little is known about degradation of these environmental pollutants by fungi from marine origin. Therefore, this study aimed to select one PAHs degrader among three marine-derived basidiomycete fungi and to study its pyrene detoxification/degradation. Marasmiellus sp. CBMAI 1062 showed higher levels of pyrene and BaP degradation and was subjected to studies related to pyrene degradation optimization using experimental design, acute toxicity, organic carbon removal (TOC), and metabolite evaluation. The experimental design resulted in an efficient pyrene degradation, reducing the experiment time while the PAH concentration applied in the assays was increased. The selected fungus was able to degrade almost 100% of pyrene (0.08mgmL -1 ) after 48h of incubation under saline condition, without generating toxic compounds and with a TOC reduction of 17%. Intermediate metabolites of pyrene degradation were identified, suggesting that the fungus degraded the compound via the cytochrome P450 system and epoxide hydrolases. These results highlight the relevance of marine-derived fungi in the field of PAH bioremediation, adding value to the blue biotechnology. Copyright © 2018. Published by Elsevier Editora Ltda.

Avaliação de pontas de jato plano na deposição da calda de pulverização com diferentes combinações de plantas de feijão, Brachiaria plantaginea e Bidens pilosa Evaluation of flat fan nozzles in spray deposition on different combinations of bean blants, Brachiaria plantaginea and Bidens pilosa

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A.C.P. Rodrigues-Costa

2010-01-01

Full Text Available Objetivou-se com este trabalho avaliar a ponta XR na deposição da calda de pulverização com diferentes combinações de plantas de feijão, Brachiaria plantaginea e Bidens pilosa, em dois volumes de aplicação, com e sem a adição de surfatante Silwet. Foi utilizado como traçador o corante Azul Brilhante FDC -1 na concentração de 500 ppm para quantificar a deposição. Os tratamentos constituíram-se de sete combinações de plantas: (feijão, (B. plantaginea, (B. pilosa, (feijão + B. plantaginea, (feijão + B. pilosa, (B. plantaginea + B. pilosa e (feijão + B. plantaginea + B. pilosa. O delineamento experimental foi o inteiramente casualizado. Foram avaliadas as pontas de jato plano XR 110015 VS e XR 11002 VS com volumes de aplicação de 150 e 200 L ha-1, respectivamente, com e sem a presença do Silwet a 0,05% v v-1. Após a aplicação, as plantas foram imediatamente coletadas e, em seguida, lavadas em 100 mL de água destilada, para posterior quantificação do traçador em espectrofotômetro. As pontas XR apresentaram comportamento distinto na deposição das gotas de pulverização nas espécies estudadas; a adição de um surfatante à calda de pulverização aumentou a uniformidade da deposição nos alvos e contribuiu para a redução do volume de aplicação.The objective of this study was to evaluate flat fan nozzle spray deposition on different combinations of the common bean plants, Brachiaria plantaginea and Bidens pilosa, in two volumes of application, with and without the addition of surfactant. Brilliant blue FDC -1 was used as tracer solution at the concentration of 500 ppm to evaluate the deposition. The treatments consisted of 7 combinations of plants: (common bean; (B. plantaginea; (B. pilosa; (common bean + B. plantaginea; (common bean + B. pilosa; (B. plantaginea + B. pilosa and (common bean + B. plantaginea + B. pilosa. The experiment was arranged in a randomized block design. The flat fan nozzles XR 110015 VS

Produção e composição química da Brachiaria brizantha cv. MG-4 sob efeito de adubação com NPK - doi: 10.4025/actascianimsci.v33i2.9392 Yield and chemical composition of Brachiaria brizantha cv. MG-4 under the effect of NPK fertilization - doi: 10.4025/actascianimsci.v33i2.9392

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Pedro Zione de Souza

2011-04-01

Full Text Available O objetivo deste trabalho foi avaliar os efeitos de combinações de doses de nitrogênio, fósforo e potássio sobre a produção de matéria seca e composição química de Brachiaria brizantha cv. MG-4. O experimento foi composto por 16 tratamentos de NPK, conforme matriz experimental Plan Puebla II, distribuídos em delineamento inteiramente casualizado com cinco repetições. Utilizou-se um Argissolo Vermelho-Amarelo Distrófico Arênico e, como fonte de N, P e K, foram utilizados sulfato de amônio e uréia, superfosfato triplo e cloreto de potássio, respectivamente. O material coletado foi separado em colmo e folha, e pré-seco para a determinação da produção matéria seca de folhas (MSF, colmos (MSC e total (MST, teor de proteína bruta (PB, N, P e K. A adubação promoveu incremento na produção da B. brizantha cv. MG-4, cujas doses de 360-370-360 g vaso-1 de NPK, respectivamente, proporcionaram 95% da maior produção de MST observada. As produtividades máximas foram nas doses de 373, 407 e 317 mg dm-3 de N de solo para MST, MSF e MSC, respectivamente. As doses de N proporcionaram incrementos nos teores de PB das folhas. As adubações fosfatada e nitrogenada proporcionaram aumento na quantidade acumulada de N, P e K na B. brizantha cv. MG-4.The objective of this work was to evaluate the effects of combinations of nitrogen (N, phosphorus (P and potassium (K on the dry matter yield and chemical composition of Brachiaria brizantha cv. MG-4. The experiment consisted of 16 combination levels of NPK, according to experimental matrix Plan Puebla II, in a completely randomized design with five replications. It used a dystrophic Red Yellow Sand-Argisol; ammonium and urea sulfate, triple super phosphate and potassium chloride were used as sources of N, P and K, respectively. The harvested material was separated into leaves and stem and submitted to dry matter yield (DMY evaluations of the aerial part, crude protein (CP and determination

KEBERADAAN FUNGI MIKORIZA ARBUSKULA DI KAWASAN TAILING TAMBANG EMAS TIMIKA SEBAGAI UPAYA REHABILITASI LAHAN RAMAH LINGKUNGAN (The Presence of Arbuscular Mycorrhizal Fungi in the Tailings of Mining Gold Timika as An Attempt of Environmentally Friendly

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Suharno Suharno

2015-01-01

Full Text Available ABSTRAK Fungi mikoriza arbuskula (FMA berperan penting dalam menunjang rehabilitasi lahan terdegradasi, termasuk lahan tailing. Tujuan penelitian ini adalah untuk mengetahui keberadaan FMA lokal di lahan tailing tambang emas Timika – Papua, Indonesia. Metode yang digunakan adalah survei dengan mengisolasi FMA dari rhizosfer beberapa jenis tumbuhan dominan di kawasan daerah pengendapan pasir sisa tambang. Pengecatan akar untuk melihat infeksi oleh FMA dilakukan dengan trypane blue, sedangkan perhitungan persen infeksinya dilakukan dengan metode slide. Keberadaan spora FMA dilakukan dengan metode wet sieving. Hasil penelitian menunjukkan bahwa terdapat FMA di lahan tailing di kawasan pengendapan Modified Ajkwa Deposition Area (ModADA. Persentase infeksi tertinggi (>50% diketahui pada jenis tumbuhan Ficus adenosperma (86,7%, Brachiaria sp (73,3%, Amomum sp (66,7%, Bidens pilosa (63,3%, dan Musaenda frondosa (56,7%, sedangkan beberapa jenis lain mempunyai persen infeksi yang lebih rendah. Jumlah spora pada rhizosfer tumbuhan Brachiaria sp., F. adenosperma, dan Amomum sp., merupakan yang tertinggi dibanding dengan tumbuhan lain yakni 17, 13, dan 11 spora per 10 g tanah.  ABSTRACT Arbuscular Mycorrhizal Fungi (AMF has an important role in supporting the rehabilitation of degraded land such as tailings. The purpose of this research was to reveal the existence of indigenous AMF in tailing area of gold mine in Timika – Papua, Indonesia. The method was a survey by isolating some types of AMF from rhizosphere of dominant plant in the deposit area of mine sand residue. To define the AMF infected roots was conducted painting roots using trypane blue, where as the calculation of percent infection was carried out using slide methods. The presence of spores of AMF was done by wet sieving method. The results showed that AMF was found in tailings deposition on the Modified Ajkwa Deposition Area (ModADA. The highest percentage infections (>50% was found under

Degradation Capability of n-hexadecane Degrading Bacteria from Petroleum Contaminated Soils

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PENG Huai-li

2017-05-01

Full Text Available Samplings were performed in the petroleum contaminated soils of Dongying, Shandong Province of China. Degrading bacteria was isolated through enrichment in a Bushnel-Hass medium, with n-hexadecane as the sole source of carbon and energy. Then the isolated strains were identified by amplification of 16S rDNA gene and sequencing. The strain TZSX2 was selected as the powerful bacteria with stronger degradation ability, which was then identified as Rhodococcus hoagii genera based on the constructing results of the phylogenetic tree. The optimum temperature that allowed both high growth and efficient degradation ratio was in the scope of 28~36 ℃, and gas chromatography results showed that approximately more than 30% of n-hexadecane could be degraded in one week of incubation within the temperature range. Moreover, the strain TZSX2 was able to grow in high concentrations of n-hexadecane. The degradation rate reached 79% when the initial n-hexadecane concentration was 2 mL·L-1,while it still achieved 12% with n-hexadecane concentration of 20 mL·L-1. The optimal pH was 9 that allowed the highest growth and the greatest degradation rate of 91%. Above all, the screened strain TZSX2 showed high capabilities of alkali tolerance with excellent degradation efficiency for even high concentration of n-hexadecane, and thus it would be quite suitable for the remediation of petroleum contaminated soils especially in the extreme environment.

Microclimate and soil moisture in a silvopastoral system in southeastern Brazil

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José Ricardo Macedo Pezzopane

2015-03-01

Full Text Available In this study, the microclimate changes in silvopastoral systems are quantified at different time and spatial scales and compared with single-pasture systems. The study was conducted in a silvopastoral system in São Carlos, Brazil (22°01' South and 47°53' West. The silvopastoral system consisted of grass pastures [Urochloa (sin. Brachiaria decumbens cv. Basilik] lined with strips of native trees spaced at 17 m. Continuous microclimate measurements (air temperature, relative humidity, wind speed, and incident photosynthetically active radiation were carried out from September 2010 to September 2012 at two positions of the silvopastoral system (2.0 and 8.5 m from the rows of trees and at a pasture under full sunlight, located in an adjacent area. The soil moisture was monitored weekly from 24 March 2010 to 1 April 2012 at distances of 0.0, 2.0, 4.75, and 8.5 m from the rows of trees. The rows of native trees reduced wind speeds (46% reduction and changed the photosynthetically active radiation incidence pattern on the pasture (up to 40% reduction of incidence at the point nearest to the trees. The combined action of these factors promoted thermal and air humidity changes on the pasture at the different points measured. With respect to soil moisture, there was greater soil moisture removal at the sampling points near the rows of native trees under the silvopastoral system, mainly due to enhanced exploration by tree roots at greater depths in dry spells or early dry periods, when compared with the midpoints between the rows.

Formigas como bioindicadores da qualidade do solo em sistema integrado lavoura-pecuária

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Rafael Aparecido Crepaldi

2014-05-01

Full Text Available O objetivo deste trabalho foi avaliar a comunidade de formigas em sistemas envolvendo a rotação entre lavoura e pecuária, sob plantio direto, comparado a outros sistemas de manejo e com sistemas naturais da região. O estudo foi conduzido no Município de Dourados, MS, sob Argissolo Vermelho distroférrico típico, num sistema integrado lavoura-pecuária, em plantio direto, rotacionado a cada dois anos. Outros sistemas de manejo avaliados, para comparação, incluíram o sistema convencional (aração e gradagem, sistema plantio direto e pastagem cultivada continuamente com Brachiaria decumbens, além de dois fragmentos de vegetação nativa, nos biomas Cerrado e Floresta Semidecídua. A coleta de solo foi realizada no período chuvoso (safra 2009/2010, sendo as amostragens de serapilheira realizadas com a utilização de extratores do tipo mini-Winkler, seguindo o protocolo ALL (Ants of the Leaf Litter. Os resultados indicaram morfoespécies de Strumygenys sp. e Hypoponera sp. como potencial bioindicadores de qualidade do solo. O estudo demonstrou que a importância da manutenção de fragmentos florestais (Cerrado e Floresta Semidecídua e implementação de sistemas integrados, tais como lavoura-pecuária, são menos impactantes para a mesofauna de solo e contribuem para a conservação da diversidade de formigas e manutenção da qualidade do solo.

Ordinal classification of vegetation along mangla dam, mirpur, ajk

International Nuclear Information System (INIS)

Urooj, R.; Ahmad, S.S.

2015-01-01

Vegetation plays an important role in ecosystem maintenance. But the construction of dams transform the riparian vegetation into impoundment region. The present study was conducted to identify and quantify herbaceous flora around the vicinity of Mangla dam. Study area was divided into two zones on the basis of distance from the dam boundary. Pattern of vegetation distribution and their association in area was grouped in to different communities by using ordination techniques. Two ordination techniques TWINSPAN and DECORANA were used. A total of 37 species belonging to 17 families were identified from fifty quadrats. Random sampling was done by using 1*1 m sized quadrat. Percentage of vegetation was assessed by using Domin cover scale. TWINSPAN classified two groups and four communities in Zone-I, while in Zone-II two groups and six communities were formed. Dominance curve showed that Cynodon dactylon, Desmostachya bipinnata and Rhynchosia minima were dominant species in Zone-I and Croton bonplandianus, C. dactylon, D. bipinnata and Brachiaria decumbens were frequent species in Zone-II. DCA as indirect multivariate technique based on reciprocal averaging determined the environmental gradients that affect the species richness and also verified the groups of species and indicated four communities in both Zones. Monte Carlo test of significance was used to analyze stress in relation to number of axis/dimensionality under Non-metric Multidimensional Scaling (NMS) through p-value. This study provided the significant results of least abundant and most abundant herbaceous species around the dam which will be helpful for biodiversity conservation and in decision making for further land planning

Artificial infestation of Boophilus microplus in beef cattle heifers of four genetic groups

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Ana Mary da Silva

2007-01-01

Full Text Available Resistance of beef cattle heifers to the cattle tick Boophilus microplus was evaluated by artificial infestation of 66 beef cattle heifers of the following genetic groups: 16 Nelore (NE, 18 Canchim x Nelore (CN, 16 Angus x Nelore (AN and 16 Simmental x Nelore (SN. The animals, with a mean age of 16.5 months, were maintained with no chemical tick control in a Brachiaria decumbens pasture. Four artificial infestations with 20,000 B. microplus larvae were carried out 14 days apart and from day 18 to day 22 of each infestation the number of engorged female ticks (> 4.5 mm was counted on the left side of each heifer. Data were analyzed as the percentage of return (PR = percentage of ticks counted relative to the number infested, transformed to (PR¼, and as log10 (Cij + 1, in which Cij is the number of ticks in each infestation, using the least squares method with a model that included the effects of genetic group (GG, animal within GG (error a, infestation number (I, GG x I and the residual (error b. Results indicated a significant GG x I interaction, because AN and SN heifers had a higher percentage of return than CN and NE heifers, while CN heifers showed a higher percentage of return than the NE heifers only in infestations 3 and 4. Transformed percentages of return were NE = 0.35 ± 0.06, AN = 0.89 ± 0.06, CN = 0.54 ± 0.05 and SN = 0.85 ± 0.06.

A retrospective serologic survey of hantavirus infections in the county of Cássia dos Coqueiros, State of São Paulo, Brazil

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Soraya Jabur Badra

2012-08-01

Full Text Available INTRODUCTION: In recent years, hantavirus infections producing severe diseases have obtained an increased attention from public health authorities from the countries of Eurasia to the Americas. Brazil has reported 1,300 cases of hantavirus cardiopulmonary syndrome (HCPS from 1993 to 2010, with about 80 of them occurring in the northeast of the State of São Paulo, with 48% fatality rate. Araraquara virus was the causative agent of HCPS in the region. Considering that hantaviruses causing human disease in the Americas were unknown until 1993, we have looked for hantavirus infections in the population of Cássia dos Coqueiros county, northeast of the State of São Paulo, Brazil, before this time. This county has about 2,800 inhabitants and an economy based on agriculture, including cultivation of Brachiaria decumbens grass. The grass seeds are an important rodent attraction, facilitating transmission of hantavirus to man. Four HCPS cases were reported so far in the county. METHODS: In this study, 1,876 sera collected from 1987 to 1990 were tested for IgG to hantavirus by IgG-ELISA, using the N recombinant protein of Araraquara virus as antigen. RESULTS: Positive results were observed in 89 (4.7% samples, which were all collected in 1987. The positivity among urban inhabitants was 5.3%, compared with 4.3% among those living in rural areas. CONCLUSIONS: Our results showed that hantavirus infections occurred in Cássia dos Coqueiros, completely unrecognized, even before hantaviruses were described in the Americas.

Microbiological and faunal soil attributes of coffee cultivation under different management systems in Brazil

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D. R. Lammel

Full Text Available Abstract Brazil is the biggest coffee producer in the world and different plantation management systems have been applied to improve sustainability and soil quality. Little is known about the environmental effects of these different management systems, therefore, the goal of this study was to use soil biological parameters as indicators of changes. Soils from plantations in Southeastern Brazil with conventional (CC, organic (OC and integrated management systems containing intercropping of Brachiaria decumbens (IB or Arachis pintoi (IA were sampled. Total organic carbon (TOC, microbial biomass carbon (MBC and nitrogen (MBN, microbial activity (C-CO2, metabolic quotient (qCO2, the enzymes dehydrogenase, urease, acid phosphatase and arylsulphatase, arbuscular mycorrhizal fungi (AMF colonization and number of spores and soil fauna were evaluated. The greatest difference between the management systems was seen in soil organic matter content. The largest quantity of TOC was found in the OC, and the smallest was found in IA. TOC content influenced soil biological parameters. The use of all combined attributes was necessary to distinguish the four systems. Each management presented distinct faunal structure, and the data obtained with the trap method was more reliable than the TSBF (Tropical Soils method. A canonic correlation analysis showed that Isopoda was correlated with TOC and the most abundant order with OC. Isoptera was the most abundant faunal order in IA and correlated with MBC. Overall, OC had higher values for most of the biological measurements and higher populations of Oligochaeta and Isopoda, corroborating with the concept that the OC is a more sustainable system.

Weed supression by smother crops and selective herbicides

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Severino Francisco José

2004-01-01

Full Text Available Using a smother crop is thought to suppress weed density and to add other beneficial effects in sustainable agricultural systems. Weed suppression ought to be considered an essential component of integrated weed management. However, very little is known about the effects of green manure plants on weeds. This study evaluated the influence of three green manure species on weed suppression and selectivity of herbicides. A field experiment was designed to determine the effect of the green manure species Crotalaria juncea, Arachis pintoi and pigeon pea on the weeds Brachiaria decumbens, guineagrass and hairy beggarticks, and on the natural weed infestation in the inter rows area of an avocado orchard. The weed species were suppressed differently by each green manure species. Soil samples collected from the field experiment presented a residual effect, of at least 30 d, in suppressing weed seed bank recruitment; this residual effect was caused by the residues of the green manure present in the soil. When the green manure was incorporated into the top 5 cm of soil or left on the surface, in a greenhouse experiment, the emergence of weed seeds was significantly inhibited, depending on the species, and on the amount and depth of green manure incorporation. Greenhouse experiments indicate that pre-emergence herbicides cause lower phytotoxicity than post-emergence Arachis pintoi. Smother crops using green manure species, when well established in an area, provide additional weed control to the cropping system and are effective and valuable tools in integrated weed management.

Microbiological and faunal soil attributes of coffee cultivation under different management systems in Brazil.

Science.gov (United States)

Lammel, D R; Azevedo, L C B; Paula, A M; Armas, R D; Baretta, D; Cardoso, E J B N

2015-11-01

Brazil is the biggest coffee producer in the world and different plantation management systems have been applied to improve sustainability and soil quality. Little is known about the environmental effects of these different management systems, therefore, the goal of this study was to use soil biological parameters as indicators of changes. Soils from plantations in Southeastern Brazil with conventional (CC), organic (OC) and integrated management systems containing intercropping of Brachiaria decumbens (IB) or Arachis pintoi (IA) were sampled. Total organic carbon (TOC), microbial biomass carbon (MBC) and nitrogen (MBN), microbial activity (C-CO2), metabolic quotient (qCO2), the enzymes dehydrogenase, urease, acid phosphatase and arylsulphatase, arbuscular mycorrhizal fungi (AMF) colonization and number of spores and soil fauna were evaluated. The greatest difference between the management systems was seen in soil organic matter content. The largest quantity of TOC was found in the OC, and the smallest was found in IA. TOC content influenced soil biological parameters. The use of all combined attributes was necessary to distinguish the four systems. Each management presented distinct faunal structure, and the data obtained with the trap method was more reliable than the TSBF (Tropical Soils) method. A canonic correlation analysis showed that Isopoda was correlated with TOC and the most abundant order with OC. Isoptera was the most abundant faunal order in IA and correlated with MBC. Overall, OC had higher values for most of the biological measurements and higher populations of Oligochaeta and Isopoda, corroborating with the concept that the OC is a more sustainable system.

Drift Degradation Analysis

International Nuclear Information System (INIS)

D. Kicker

2004-01-01

Degradation of underground openings as a function of time is a natural and expected occurrence for any subsurface excavation. Over time, changes occur to both the stress condition and the strength of the rock mass due to several interacting factors. Once the factors contributing to degradation are characterized, the effects of drift degradation can typically be mitigated through appropriate design and maintenance of the ground support system. However, for the emplacement drifts of the geologic repository at Yucca Mountain, it is necessary to characterize drift degradation over a 10,000-year period, which is well beyond the functional period of the ground support system. This document provides an analysis of the amount of drift degradation anticipated in repository emplacement drifts for discrete events and time increments extending throughout the 10,000-year regulatory period for postclosure performance. This revision of the drift degradation analysis was developed to support the license application and fulfill specific agreement items between the U.S. Nuclear Regulatory Commission (NRC) and the U.S. Department of Energy (DOE). The earlier versions of ''Drift Degradation Analysis'' (BSC 2001 [DIRS 156304]) relied primarily on the DRKBA numerical code, which provides for a probabilistic key-block assessment based on realistic fracture patterns determined from field mapping in the Exploratory Studies Facility (ESF) at Yucca Mountain. A key block is defined as a critical block in the surrounding rock mass of an excavation, which is removable and oriented in an unsafe manner such that it is likely to move into an opening unless support is provided. However, the use of the DRKBA code to determine potential rockfall data at the repository horizon during the postclosure period has several limitations: (1) The DRKBA code cannot explicitly apply dynamic loads due to seismic ground motion. (2) The DRKBA code cannot explicitly apply loads due to thermal stress. (3) The DRKBA

Drift Degradation Analysis

Energy Technology Data Exchange (ETDEWEB)

D. Kicker

2004-09-16

Degradation of underground openings as a function of time is a natural and expected occurrence for any subsurface excavation. Over time, changes occur to both the stress condition and the strength of the rock mass due to several interacting factors. Once the factors contributing to degradation are characterized, the effects of drift degradation can typically be mitigated through appropriate design and maintenance of the ground support system. However, for the emplacement drifts of the geologic repository at Yucca Mountain, it is necessary to characterize drift degradation over a 10,000-year period, which is well beyond the functional period of the ground support system. This document provides an analysis of the amount of drift degradation anticipated in repository emplacement drifts for discrete events and time increments extending throughout the 10,000-year regulatory period for postclosure performance. This revision of the drift degradation analysis was developed to support the license application and fulfill specific agreement items between the U.S. Nuclear Regulatory Commission (NRC) and the U.S. Department of Energy (DOE). The earlier versions of ''Drift Degradation Analysis'' (BSC 2001 [DIRS 156304]) relied primarily on the DRKBA numerical code, which provides for a probabilistic key-block assessment based on realistic fracture patterns determined from field mapping in the Exploratory Studies Facility (ESF) at Yucca Mountain. A key block is defined as a critical block in the surrounding rock mass of an excavation, which is removable and oriented in an unsafe manner such that it is likely to move into an opening unless support is provided. However, the use of the DRKBA code to determine potential rockfall data at the repository horizon during the postclosure period has several limitations: (1) The DRKBA code cannot explicitly apply dynamic loads due to seismic ground motion. (2) The DRKBA code cannot explicitly apply loads due to thermal

Cometabolic Degradation of Dibenzofuran and Dibenzothiophene by a Naphthalene-Degrading Comamonas sp. JB.

Science.gov (United States)

Ji, Xiangyu; Xu, Jing; Ning, Shuxiang; Li, Nan; Tan, Liang; Shi, Shengnan

2017-12-01

Comamonas sp. JB was used to investigate the cometabolic degradation of dibenzofuran (DBF) and dibenzothiophene (DBT) with naphthalene as the primary substrate. Dehydrogenase and ATPase activity of the growing system with the presence of DBF and DBT were decreased when compared to only naphthalene in the growing system, indicating that the presence of DBF and DBT inhibited the metabolic activity of strain JB. The pathways and enzymes involved in the cometabolic degradation were tested. Examination of metabolites elucidated that strain JB cometabolically degraded DBF to 1,2-dihydroxydibenzofuran, subsequently to 2-hydroxy-4-(3'-oxo-3'H-benzofuran-2'-yliden)but-2-enoic acid, and finally to catechol. Meanwhile, strain JB cometabolically degraded DBT to 1,2-dihydroxydibenzothiophene and subsequently to the ring cleavage product. A series of naphthalene-degrading enzymes including naphthalene dioxygenase, 1,2-dihydroxynaphthalene dioxygenase, salicylaldehyde dehydrogenase, salicylate hydroxylase, and catechol 2,3-oxygenase have been detected, confirming that naphthalene was the real inducer of expression the degradation enzymes and metabolic pathways were controlled by naphthalene-degrading enzymes.

Successful phytoremediation of crude-oil contaminated soil at an oil exploration and production company by plants-bacterial synergism.

Science.gov (United States)

Fatima, Kaneez; Imran, Asma; Amin, Imran; Khan, Qaiser M; Afzal, Muhammad

2018-06-07

Phytoremediation is a promising approach for the cleanup of soil contaminated with petroleum hydrocarbons. This study aimed to develop plant-bacterial synergism for the successful remediation of crude oil-contaminated soil. A consortia of three endophytic bacteria was augmented to two grasses, Leptochloa fusca and Brachiaria mutica, grown in oil-contaminated soil (46.8 g oil kg -1 soil) in the vicinity of an oil exploration and production company. Endophytes augmentation improved plant growth, crude oil degradation, and soil health. Maximum oil degradation (80%) was achieved with B. mutica plants augmented with the endophytes and it was significantly (P oil reduction indicates that catabolic gene expression is important for hydrocarbon mineralization. This investigation showed that the use of endophytes with appropriate plant is an effective strategy for the cleanup of oil-contaminated soil under field conditions.

Intermittent degradation and schizotypy

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Matthew W. Roché

2015-06-01

Full Text Available Intermittent degradation refers to transient detrimental disruptions in task performance. This phenomenon has been repeatedly observed in the performance data of patients with schizophrenia. Whether intermittent degradation is a feature of the liability for schizophrenia (i.e., schizotypy is an open question. Further, the specificity of intermittent degradation to schizotypy has yet to be investigated. To address these questions, 92 undergraduate participants completed a battery of self-report questionnaires assessing schizotypy and psychological state variables (e.g., anxiety, depression, and their reaction times were recorded as they did so. Intermittent degradation was defined as the number of times a subject’s reaction time for questionnaire items met or exceeded three standard deviations from his or her mean reaction time after controlling for each item’s information processing load. Intermittent degradation scores were correlated with questionnaire scores. Our results indicate that intermittent degradation is associated with total scores on measures of positive and disorganized schizotypy, but unrelated to total scores on measures of negative schizotypy and psychological state variables. Intermittent degradation is interpreted as potentially derivative of schizotypy and a candidate endophenotypic marker worthy of continued research.

Characterization and degradation potential of diesel-degrading bacterial strains for application in bioremediation.

Science.gov (United States)

Balseiro-Romero, María; Gkorezis, Panagiotis; Kidd, Petra S; Van Hamme, Jonathan; Weyens, Nele; Monterroso, Carmen; Vangronsveld, Jaco

2017-10-03

Bioremediation of polluted soils is a promising technique with low environmental impact, which uses soil organisms to degrade soil contaminants. In this study, 19 bacterial strains isolated from a diesel-contaminated soil were screened for their diesel-degrading potential, biosurfactant (BS) production, and biofilm formation abilities, all desirable characteristics when selecting strains for re-inoculation into hydrocarbon-contaminated soils. Diesel-degradation rates were determined in vitro in minimal medium with diesel as the sole carbon source. The capacity to degrade diesel range organics (DROs) of strains SPG23 (Arthobacter sp.) and PF1 (Acinetobacter oleivorans) reached 17-26% of total DROs after 10 days, and 90% for strain GK2 (Acinetobacter calcoaceticus). The amount and rate of alkane degradation decreased significantly with increasing carbon number for strains SPG23 and PF1. Strain GK2, which produced BSs and biofilms, exhibited a greater extent, and faster rate of alkane degradation compared to SPG23 and PF1. Based on the outcomes of degradation experiments, in addition to BS production, biofilm formation capacities, and previous genome characterizations, strain GK2 is a promising candidate for microbial-assisted phytoremediation of diesel-contaminated soils. These results are of particular interest to select suitable strains for bioremediation, not only presenting high diesel-degradation rates, but also other characteristics which could improve rhizosphere colonization.

Developments in polymer degradation - 7

International Nuclear Information System (INIS)

Grassie, N.

1987-01-01

A selection of topics which are representative of the continually expanding area of polymer degradation is presented. The aspects emphasised include the products of degradation of specific polymers, degradation by high energy radiation and mechanical forces, fire retardant studies and the special role of small radicals in degradation processes. (author)

Purex diluent degradation

International Nuclear Information System (INIS)

Tallent, O.K.; Mailen, J.C.; Pannell, K.D.

1984-02-01

The chemical degradation of normal paraffin hydrocarbon (NPH) diluents both in the pure state and mixed with 30% tributyl phosphate (TBP) was investigated in a series of experiments. The results show that degradation of NPH in the TBP-NPH-HNO 3 system is consistent with the active chemical agent being a radical-like nitrogen dioxide (NO 2 ) molecule, not HNO 3 as such. Spectrophotometric, gas chromatographic, mass spectrographic, and titrimetric methods were used to identify the degradation products, which included alkane nitro and nitrate compounds, alcohols, unsaturated alcohols, nitro alcohols, nitro alkenes, ketones, and carboxylic acids. The degradation rate was found to increase with increases in the HNO 3 concentration and the temperature. The rate was decreased by argon sparging to remove NO 2 and by the addition of butanol, which probably acts as a NO 2 scavenger. 13 references, 11 figures

Iodinated contrast media electro-degradation: process performance and degradation pathways.

Science.gov (United States)

Del Moro, Guido; Pastore, Carlo; Di Iaconi, Claudio; Mascolo, Giuseppe

2015-02-15

The electrochemical degradation of six of the most widely used iodinated contrast media was investigated. Batch experiments were performed under constant current conditions using two DSA® electrodes (titanium coated with a proprietary and patented mixed metal oxide solution of precious metals such as iridium, ruthenium, platinum, rhodium and tantalum). The degradation removal never fell below 85% (at a current density of 64 mA/cm(2) with a reaction time of 150 min) when perchlorate was used as the supporting electrolyte; however, when sulphate was used, the degradation performance was above 80% (at a current density of 64 mA/cm(2) with a reaction time of 150 min) for all of the compounds studied. Three main degradation pathways were identified, namely, the reductive de-iodination of the aromatic ring, the reduction of alkyl aromatic amides to simple amides and the de-acylation of N-aromatic amides to produce aromatic amines. However, as amidotrizoate is an aromatic carboxylate, this is added via the decarboxylation reaction. The investigation did not reveal toxicity except for the lower current density used, which has shown a modest toxicity, most likely for some reaction intermediates that are not further degraded. In order to obtain total removal of the contrast media, it was necessary to employ a current intensity between 118 and 182 mA/cm(2) with energy consumption higher than 370 kWh/m(3). Overall, the electrochemical degradation was revealed to be a reliable process for the treatment of iodinated contrast media that can be found in contaminated waters such as hospital wastewater or pharmaceutical waste-contaminated streams. Copyright © 2014 Elsevier B.V. All rights reserved.

Efeito da suplementação sobre a digestibilidade dos nutrientes e desempenho de bezerros lactentes mantidos em pastagens de Brachiaria brizantha - DOI: 10.4025/actascianimsci.v32i1.4849 Effect of supplementation on nutrient digestibility and performance of lactating calves fed with Brachiaria brizantha pastures - DOI: 10.4025/actascianimsci.v32i1.4849

Directory of Open Access Journals (Sweden)

Glauco Mora Ribeiro

2009-12-01

Full Text Available Foi avaliado o efeito da suplementação e do tipo do suplemento sobre a digestibilidade dos nutrientes e o desempenho de bezerros Canchim lactentes mantidos em pastagem de Brachiaria brizantha cv. Marandu durante os meses de fevereiro a maio. Os tratamentos foram: sem e com suplementação em creep-feeding com concentrado proteico, com concentrado energético e com concentrado energético-proteico. Em quadrado latino, foi avaliada a digestibilidade dos nutrientes, utilizando-se quatro bezerros mantidos em baias individuais, recebendo feno da mesma forrageira e com mamadas controladas duas vezes ao dia. O desempenho foi avaliado em delineamento inteiramente casualizado, sendo os 23 bezerros mantidos junto com as matrizes. A suplementação com concentrado energético-proteico determinou melhor ingestão e aproveitamento dos nutrientes (65% de digestibilidade da matéria seca, desempenho dos bezerros (ganhos de peso de 0,98 kg dia-1 e manutenção do peso e das reservas corporais das matrizes. A utilização de suplemento proteico não mostrou bons resultados, sendo estes inferiores inclusive ao desempenho dos bezerros que não receberam suplementação, 0,56 e 0,77 kg dia-1, respectivamente. O desempenho dos bezerros no tratamento sem suplementação foi semelhante àqueles que receberam suplemento energético, porém as matrizes tiveram redução mais acentuada do peso corporal e das reservas energéticas. A suplementação com concentrado energético-proteico para bezerros lactentes mantidos em pastagens de Brachiaria brizantha cv. Marandu no início da seca mostrou ser uma técnica que beneficia o desempenho desses animais e das matrizesThis study evaluated the effect of supplementation and the type of supplement on nutrient digestibility and performance of lactating calves fed with Brachiara brizantha cv. Marandu pasture from February to May. The treatments were: supplementation in creep-feeding with protein concentrate, with energy

Anthocyanins degradation during storage of Hibiscus sabdariffa extract and evolution of its degradation products.

Science.gov (United States)

Sinela, André; Rawat, Nadirah; Mertz, Christian; Achir, Nawel; Fulcrand, Hélène; Dornier, Manuel

2017-01-01

Degradation parameters of two main anthocyanins from roselle extract (Hibiscus sabdariffa L.) stored at different temperatures (4-37°C) over 60days were determined. Anthocyanins and some of their degradation products were monitored and quantified using HPLC-MS and DAD. Degradation of anthocyanins followed first-order kinetics and reaction rate constants (k values), which were obtained by non-linear regression, showed that the degradation rate of delphinidin 3-O-sambubioside was higher than that of cyanidin 3-O-sambubioside with k values of 9.2·10(-7)s(-1) and 8.4·10(-7)s(-1) at 37°C respectively. The temperature dependence of the rate of anthocyanin degradation was modeled by the Arrhenius equation. Degradation of delphinidin 3-O-sambubioside (Ea=90kJmol(-1)) tended to be significantly more sensitive to an increase in temperature than cyanidin 3-O-sambubioside (Ea=80kJmol(-1)). Degradation of these anthocyanins formed scission products (gallic and protocatechuic acids respectively) and was accompanied by an increase in polymeric color index. Copyright © 2016 Elsevier Ltd. All rights reserved.

A MONOGRAPH OF THE GENUS DIPLODISCUS* Turcz. (TILIACEAE

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A. J. G. H. KOSTERMANS

2014-01-01

Full Text Available 1. Seven species of the genus Diplodiscus are described, of which three(D. microlepis, D. parviflorus and D. decumbens are new to science, and one (D. hookerianus was formerly described as Pentace (for the description of D. decumbens cf. p. 264.2. The area of distribution of the genus covers the Malay Peninsula,Borneo and the Philippines.3. The affinities of the genus are discussed.4. A key to the species is presented.

Drift Degradation Analysis

International Nuclear Information System (INIS)

G.H. Nieder-Westermann

2005-01-01

The outputs from the drift degradation analysis support scientific analyses, models, and design calculations, including the following: (1) Abstraction of Drift Seepage; (2) Seismic Consequence Abstraction; (3) Structural Stability of a Drip Shield Under Quasi-Static Pressure; and (4) Drip Shield Structural Response to Rock Fall. This report has been developed in accordance with ''Technical Work Plan for: Regulatory Integration Modeling of Drift Degradation, Waste Package and Drip Shield Vibratory Motion and Seismic Consequences'' (BSC 2004 [DIRS 171520]). The drift degradation analysis includes the development and validation of rockfall models that approximate phenomenon associated with various components of rock mass behavior anticipated within the repository horizon. Two drift degradation rockfall models have been developed: the rockfall model for nonlithophysal rock and the rockfall model for lithophysal rock. These models reflect the two distinct types of tuffaceous rock at Yucca Mountain. The output of this modeling and analysis activity documents the expected drift deterioration for drifts constructed in accordance with the repository layout configuration (BSC 2004 [DIRS 172801])

Degradation of diclofenac by UV-activated persulfate process: Kinetic studies, degradation pathways and toxicity assessments.

Science.gov (United States)

Lu, Xian; Shao, Yisheng; Gao, Naiyun; Chen, Juxiang; Zhang, Yansen; Xiang, Huiming; Guo, Youluo

2017-07-01

Diclofenac (DCF) is the frequently detected non-steroidal pharmaceuticals in the aquatic environment. In this study, the degradation of DCF was evaluated by UV-254nm activated persulfate (UV/PS). The degradation of DCF followed the pseudo first-order kinetics pattern. The degradation rate constant (k obs ) was accelerated by UV/PS compared to UV alone and PS alone. Increasing the initial PS dosage or solution pH significantly enhanced the degradation efficiency. Presence of various natural water constituents had different effects on DCF degradation, with an enhancement or inhibition in the presence of inorganic anions (HCO 3 - or Cl - ) and a significant inhibition in the presence of NOM. In addition, preliminary degradation mechanisms and major products were elucidated using LC-MS/MS. Hydroxylation, decarbonylation, ring-opening and cyclation reaction involving the attack of SO 4 • - or other substances, were the main degradation mechanism. TOC analyzer and Microtox bioassay were employed to evaluate the mineralization and cytotoxicity of solutions treated by UV/PS at different times, respectively. Limited elimination of TOC (32%) was observed during the mineralization of DCF. More toxic degradation products and their related intermediate species were formed, and the UV/PS process was suitable for removing the toxicity. Of note, longer degradation time may be considered for the final toxicity removal. Copyright © 2017. Published by Elsevier Inc.

Photo-fenton degradation of diclofenac: identification of main intermediates and degradation pathway.

Science.gov (United States)

Pérez-Estrada, Leónidas A; Malato, Sixto; Gernjak, Wolfgang; Agüera, Ana; Thurman, E Michael; Ferrer, Imma; Fernández-Alba, Amadeo R

2005-11-01

In recent years, the presence of pharmaceuticals in the aquatic environment has been of growing interest. These new contaminants are important because many of them are not degraded under the typical biological treatments applied in the wastewater treatment plants and represent a continuous input into the environment. Thus, compounds such as diclofenac are present in surface waters in all Europe and a crucial need for more enhanced technologies that can reduce its presence in the environment has become evident. In this sense, advanced oxidation processes (AOPs) represent a good choice for the treatment of hazardous nonbiodegradable pollutants. This work deals with the solar photodegradation of diclofenac, an antiinflammatory drug, in aqueous solutions by photo-Fenton reaction. A pilot-scale facility using a compound parabolic collector (CPC) reactor was used for this study. Results obtained show rapid and complete oxidation of diclofenac after 60 min, and total mineralization (disappearance of dissolved organic carbon, DOC) after 100 min of exposure to sunlight. Although diclofenac precipitates during the process at low pH, its degradation takes place in the homogeneous phase governed by a precipitation-redissolution-degradation process. Establishment of the reaction pathway was made possible by a thorough analysis of the reaction mixture identifying the main intermediate products generated. Gas chromatography-mass spectrometry (GC/ MS) and liquid chromatography coupled with time-of-flight mass spectrometry (LC/TOF-MS) were used to identify 18 intermediates, in two tentative degradation routes. The main one was based on the initial hydroxylation of the phenylacetic acid moiety in the C-4 position and subsequent formation of a quinone imine derivative that was the starting point for further multistep degradation involving hydroxylation, decarboxylation, and oxidation reactions. An alternative route was based on the transient preservation of the biphenyl amino moiety

Characterization of Methane Degradation and Methane-Degrading Microbes in Alaska Coastal Water

Energy Technology Data Exchange (ETDEWEB)

Kirchman, David L. [Univ. of Delaware, Lewes, DE (United States)

2012-03-29

The net flux of methane from methane hydrates and other sources to the atmosphere depends on methane degradation as well as methane production and release from geological sources. The goal of this project was to examine methane-degrading archaea and organic carbon oxidizing bacteria in methane-rich and methane-poor sediments of the Beaufort Sea, Alaska. The Beaufort Sea system was sampled as part of a multi-disciplinary expedition (Methane in the Arctic Shelf or MIDAS) in September 2009. Microbial communities were examined by quantitative PCR analyses of 16S rRNA genes and key methane degradation genes (pmoA and mcrA involved in aerobic and anaerobic methane degradation, respectively), tag pyrosequencing of 16S rRNA genes to determine the taxonomic make up of microbes in these sediments, and sequencing of all microbial genes (metagenomes ). The taxonomic and functional make-up of the microbial communities varied with methane concentrations, with some data suggesting higher abundances of potential methane-oxidizing archaea in methane-rich sediments. Sequence analysis of PCR amplicons revealed that most of the mcrA genes were from the ANME-2 group of methane oxidizers. According to metagenomic data, genes involved in methane degradation and other degradation pathways changed with sediment depth along with sulfate and methane concentrations. Most importantly, sulfate reduction genes decreased with depth while the anaerobic methane degradation gene (mcrA) increased along with methane concentrations. The number of potential methane degradation genes (mcrA) was low and inconsistent with other data indicating the large impact of methane on these sediments. The data can be reconciled if a small number of potential methane-oxidizing archaea mediates a large flux of carbon in these sediments. Our study is the first to report metagenomic data from sediments dominated by ANME-2 archaea and is one of the few to examine the entire microbial assemblage potentially involved in

Performance of dairy heifers raised on Xaraés palissadgrass (Brachiaria brizantha cv. Xaraés pasture supplemented with two types of mineral mixture

Directory of Open Access Journals (Sweden)

Carlos Augusto B. de Carvalho

2014-01-01

Full Text Available The effects of selective (e.g. mineral supplement formulated on the basis of nutritional and clinical examination of the herd or commercial mineral supplementation of crossbred dairy heifers (Holstein-Mantiqueira, on daily weight gain (DWG, body condition score (BCS, age at first mating (AFM and the intake of mineral mixture (IMM managed on Xaraés palissadgrass pasture (Brachiaria brizantha cv. Xaraés were evaluated from February 2006 to March 2008. Structural characteristics, forage allowance and nutritional value of Xaraés palissadgrass were also evaluated. The structural variables of pasture, allowances and nutritive value of forage, besides the DWG were only affected (p<0.05 by season, with highest results for spring and summer. Throughout the experimental period (730 days, no sign of mineral deficiency was detected in heifers that ingested the selective supplement. The DWG and AFM were not influenced by the mineral mixture offered (0.52 and 0.33 kg/day during the spring/summer and in fall/winter for DWG, respectively, and 813 days of AFM. The IMM was higher for commercial mineral mixture than for selective (61.6 and 51.0g/day respectively. The BCS was slightly higher for selective (3.17 than for the commercial (3.02 mineral mixture. Thus, the selective mineral supplement was a strategy to prevent mineral deficiency in this herd and resulted in similar performance at lower costs (e.g. due to less IMM of crossbred heifers when compared with the commercial mineral supplementation.

Statistical modeling for degradation data

CERN Document Server

Lio, Yuhlong; Ng, Hon; Tsai, Tzong-Ru

2017-01-01

This book focuses on the statistical aspects of the analysis of degradation data. In recent years, degradation data analysis has come to play an increasingly important role in different disciplines such as reliability, public health sciences, and finance. For example, information on products’ reliability can be obtained by analyzing degradation data. In addition, statistical modeling and inference techniques have been developed on the basis of different degradation measures. The book brings together experts engaged in statistical modeling and inference, presenting and discussing important recent advances in degradation data analysis and related applications. The topics covered are timely and have considerable potential to impact both statistics and reliability engineering.

Survival and larval development of Spodoptera frugiperda (J E Smith) (Lepidoptera: Noctuidae) on alternatives host; Sobrevivencia e desenvolvimento larval de Spodoptera frugiperda (J E Smith) (Lepidoptera: Noctuidae) em hospedeiros alternativos

Energy Technology Data Exchange (ETDEWEB)

Sa, Verissimo G.M. de [Universidade Federal de Minas Gerais (UFMG), Montes Claros, MG (Brazil). Dept. de Agronomia; Fonseca, Bernardo V.C. [Universidade FUMEC, Belo Horizonte, MG (Brazil); Boregas, Katia G.B. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Ecologia; Waquil, Jose M. [EMBRAPA Milho e Sorgo, Sete Lagoas, MG (Brazil)]. E-mail: aaquil@cnpms.embrapa.br

2009-01-15

Two bioassays were conducted to evaluate the suitability of host plants of fall armyworm (FAW), Spodoptera frugiperda (J E Smith), in the Brazilian agro-ecosystem. Larval development and survival were analyzed by infesting leaves of maize, grain sorghum, Johnson grass, soybean, Brachiaria and tobacco with FAW newly hatched larvae in a no choice test. No significant differences of survival were observed among insects reared on different hosts, except for tobacco, where no survivors were recorded. Larvae fed on soybean and artificial diet grew larger than those fed on the other hosts. The heaviest pupa was observed from larva fed on artificial diet and the lighter from larva fed on Brachiaria grass. No significant differences were reported on larval development time on natural hosts, but it was longer for larvae reared on artificial diet. Three classes of larval development time were observed on maize, four on sorghum, Brachiaria and soybean, and five on artificial diet. Nearly 85% of FAW larvae completed development within 12 d on maize; 77% on grain sorghum, 80% on Johnson grass, 68% on Brachiaria and 83% on soybean within 14 d and 69% on artificial diet within 17 d. The host suitability to FAW decreases from maize to sorghum, soybean and Brachiaria. (author)

Survival and larval development of Spodoptera frugiperda (J E Smith) (Lepidoptera: Noctuidae) on alternatives host

International Nuclear Information System (INIS)

Sa, Verissimo G.M. de; Boregas, Katia G.B.

2009-01-01

Two bioassays were conducted to evaluate the suitability of host plants of fall armyworm (FAW), Spodoptera frugiperda (J E Smith), in the Brazilian agro-ecosystem. Larval development and survival were analyzed by infesting leaves of maize, grain sorghum, Johnson grass, soybean, Brachiaria and tobacco with FAW newly hatched larvae in a no choice test. No significant differences of survival were observed among insects reared on different hosts, except for tobacco, where no survivors were recorded. Larvae fed on soybean and artificial diet grew larger than those fed on the other hosts. The heaviest pupa was observed from larva fed on artificial diet and the lighter from larva fed on Brachiaria grass. No significant differences were reported on larval development time on natural hosts, but it was longer for larvae reared on artificial diet. Three classes of larval development time were observed on maize, four on sorghum, Brachiaria and soybean, and five on artificial diet. Nearly 85% of FAW larvae completed development within 12 d on maize; 77% on grain sorghum, 80% on Johnson grass, 68% on Brachiaria and 83% on soybean within 14 d and 69% on artificial diet within 17 d. The host suitability to FAW decreases from maize to sorghum, soybean and Brachiaria. (author)

Extensions and applications of degradation modeling

International Nuclear Information System (INIS)

Hsu, F.; Subudhi, M.; Samanta, P.K.; Vesely, W.E.

1991-01-01

Component degradation modeling being developed to understand the aging process can have many applications with potential advantages. Previous work has focused on developing the basic concepts and mathematical development of a simple degradation model. Using this simple model, times of degradations and failures occurrences were analyzed for standby components to detect indications of aging and to infer the effectiveness of maintenance in preventing age-related degradations from transforming to failures. Degradation modeling approaches can have broader applications in aging studies and in this paper, the authors discuss some of the extensions and applications of degradation modeling. The extensions and applications of the degradation modeling approaches discussed are: (a) theoretical developments to study reliability effects of different maintenance strategies and policies, (b) relating aging-failure rate to degradation rate, and (c) application to a continuously operating component

Avaliação qualitativa da pastagem de capim tanner-grass (Brachiaria arrecta, por três diferentes métodos de amostragem Quality evaluation of the tanner grass (Brachiaria arrecta pasture, by three different collection methods

Directory of Open Access Journals (Sweden)

Rafael Henrique de Tonissi e Buschinelli de Goes

2003-02-01

Full Text Available Objetivou-se avaliar a qualidade da pastagem de Brachiaria arrecta, classificada anteriormente como B. radicans utilizando-se as metodologias da extrusa, pastejo simulado e disponibilidade total. Para a coleta da extrusa, utilizaram-se três novilhos fistulados no esôfago. A disponibilidade total do pasto foi obtida pelo corte rente ao solo, com um quadrado metálico (0,5 x 0,5 m, e o pastejo simulado foi colhido manualmente. Para a digestibilidade in vitro da matéria seca, ocorreu efeito do mês de amostragem, mas não entre as metodologias de coleta utilizadas, em que a extrusa apresentou maiores valores (62,10%. Não ocorreu diferença para os teores de proteína bruta, entre os métodos do pastejo simulado e da extrusa. Os valores de PB para o método de disponibilidade total foram abaixo de 7% e os de FDN (72,3% e FDA (38,2%, encontrados para os três métodos, confirmaram que as forrageiras tropicais são ricas em parede celular. As amostras obtidas pela disponibilidade total não foram representativas da dieta ingerida pelos bovinos. O método de amostragem influiu na determinação da composição química da pastagem. O pastejo simulado pode servir para uma estimativa satisfatória da dieta selecionada por bovinos.The quality of B. radicans, former B. radicans pasture, was evaluated using extrusa collection, hand-plucked and total availability methods. Three esophageous fistulated steers were used for the extrusa collection. Samples for total availability of the pasture were collected cutting plant material close to the ground inside a metalic square (0.5 x 0.5m. hand-plucked method was performed manually. There was a significant effect for the months of collection for the in vitro dry matter disapperance, but not among the collection methods tested. The extrusa collection method showing the highest values (62.1%. There was no difference for crude protein among the simulated grazing and extrusa methods. The CP values for the total

Applications and extensions of degradation modeling

International Nuclear Information System (INIS)

Hsu, F.; Subudhi, M.; Samanta, P.K.; Vesely, W.E.

1991-01-01

Component degradation modeling being developed to understand the aging process can have many applications with potential advantages. Previous work has focused on developing the basic concepts and mathematical development of a simple degradation model. Using this simple model, times of degradations and failures occurrences were analyzed for standby components to detect indications of aging and to infer the effectiveness of maintenance in preventing age-related degradations from transforming to failures. Degradation modeling approaches can have broader applications in aging studies and in this paper, we discuss some of the extensions and applications of degradation modeling. The application and extension of degradation modeling approaches, presented in this paper, cover two aspects: (1) application to a continuously operating component, and (2) extension of the approach to analyze degradation-failure rate relationship. The application of the modeling approach to a continuously operating component (namely, air compressors) shows the usefulness of this approach in studying aging effects and the role of maintenance in this type component. In this case, aging effects in air compressors are demonstrated by the increase in both the degradation and failure rate and the faster increase in the failure rate compared to the degradation rate shows the ineffectiveness of the existing maintenance practices. Degradation-failure rate relationship was analyzed using data from residual heat removal system pumps. A simple linear model with a time-lag between these two parameters was studied. The application in this case showed a time-lag of 2 years for degradations to affect failure occurrences. 2 refs

Applications and extensions of degradation modeling

Energy Technology Data Exchange (ETDEWEB)

Hsu, F.; Subudhi, M.; Samanta, P.K. [Brookhaven National Lab., Upton, NY (United States); Vesely, W.E. [Science Applications International Corp., Columbus, OH (United States)

1991-12-31

Component degradation modeling being developed to understand the aging process can have many applications with potential advantages. Previous work has focused on developing the basic concepts and mathematical development of a simple degradation model. Using this simple model, times of degradations and failures occurrences were analyzed for standby components to detect indications of aging and to infer the effectiveness of maintenance in preventing age-related degradations from transforming to failures. Degradation modeling approaches can have broader applications in aging studies and in this paper, we discuss some of the extensions and applications of degradation modeling. The application and extension of degradation modeling approaches, presented in this paper, cover two aspects: (1) application to a continuously operating component, and (2) extension of the approach to analyze degradation-failure rate relationship. The application of the modeling approach to a continuously operating component (namely, air compressors) shows the usefulness of this approach in studying aging effects and the role of maintenance in this type component. In this case, aging effects in air compressors are demonstrated by the increase in both the degradation and failure rate and the faster increase in the failure rate compared to the degradation rate shows the ineffectiveness of the existing maintenance practices. Degradation-failure rate relationship was analyzed using data from residual heat removal system pumps. A simple linear model with a time-lag between these two parameters was studied. The application in this case showed a time-lag of 2 years for degradations to affect failure occurrences. 2 refs.

Applications and extensions of degradation modeling

Energy Technology Data Exchange (ETDEWEB)

Hsu, F.; Subudhi, M.; Samanta, P.K. (Brookhaven National Lab., Upton, NY (United States)); Vesely, W.E. (Science Applications International Corp., Columbus, OH (United States))

1991-01-01

Component degradation modeling being developed to understand the aging process can have many applications with potential advantages. Previous work has focused on developing the basic concepts and mathematical development of a simple degradation model. Using this simple model, times of degradations and failures occurrences were analyzed for standby components to detect indications of aging and to infer the effectiveness of maintenance in preventing age-related degradations from transforming to failures. Degradation modeling approaches can have broader applications in aging studies and in this paper, we discuss some of the extensions and applications of degradation modeling. The application and extension of degradation modeling approaches, presented in this paper, cover two aspects: (1) application to a continuously operating component, and (2) extension of the approach to analyze degradation-failure rate relationship. The application of the modeling approach to a continuously operating component (namely, air compressors) shows the usefulness of this approach in studying aging effects and the role of maintenance in this type component. In this case, aging effects in air compressors are demonstrated by the increase in both the degradation and failure rate and the faster increase in the failure rate compared to the degradation rate shows the ineffectiveness of the existing maintenance practices. Degradation-failure rate relationship was analyzed using data from residual heat removal system pumps. A simple linear model with a time-lag between these two parameters was studied. The application in this case showed a time-lag of 2 years for degradations to affect failure occurrences. 2 refs.