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Sample records for degraded brachiaria decumbens

  1. Ruminal degradation kinetic of Brachiaria decumbens silages with different nitrogen additives

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    Odimári Pricila Pires do Prado

    2014-02-01

    Full Text Available This study aimed to assess levels of nitrogen additive Silogen® pasto on ruminal in vitro degradability gas production in Brachiaria decumbens silages. The nitrogen additive contained bacterial strains (Bacillus subtilis, Lactobacillus curvatus, Lactobacillus plantarum and Pediococcus acidilactici and minimum nitrogen to 360 g/kg. The levels were: 0.0; 1.0; 1.5; 2.0 and 2.5%. In fractionation were calculated total carbohydrates (TC, non-fiber carbohydrates (NFC, soluble and rapidly degradable (A + B1, potentially degradable (B2 and degradable (C. The kinetic parameters of FC and NFC were estimated using the technique of in vitro gas production. Data were subjected to analysis of variance at 5%. The level additive did not influence the TC and fraction A + B1. The levels of nitrogen additive influenced the NFC, fractions B2 and C. For NFC content 2.0% showed the lowest (22.0 %. The lower levels of additive nitrogen (0, 1.0 and 1.5 % had higher fractions of B2 (average 40.2 % and lower values for the fraction C (average 20.0 % . There was no difference in the volume of gas CNF (average 86.73 mL and final volume of gas produced (average 195.79 mL. Was no influence of nitrogen additives for the time of colonization, the lowest time of 3.89 h to 1.0%. The volume of gas of FC was influenced by levels of nitrogen additives with higher values to 0 % from 1.0 %, and 114.74 and 115.09 mL, respectively. Degradation rates of FC and FNC were also affected by the concentrations of nitrogenous additives, which presented higher rates to the levels of 2.0 and 2.5%. It follows that the lower levels of additives to 1.5 % promoted the reduction of the C fraction and increased B2, and greater production of gas volume of the fiber in these silages, showing better nutritional value in these silages.

  2. Comportamento ingestivo de bezerros em pastos de Brachiaria brizantha e Brachiaria decumbens Ingestive behavior of calves on pastures of Brachiaria brizantha and Brachiaria decumbens

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    Anderson de Moura Zanine

    2006-10-01

    Full Text Available Foi conduzido um experimento com o objetivo de avaliar o comportamento de bezerros em pastagens de Brachiaria brizantha e Brachiaria decumbens, no sistema de lotação contínua com taxa de lotação variável. O delineamento experimental foi o inteiramente casualizado, com dois pastos representando os tratamentos, cada um com cinco repetições. O período experimental foi de 30 dias, sendo 20 para adaptação dos animais e 10 para avaliações, que consistiram de três, com duração de 24h cada, em intervalos de cinco dias. Os bezerros pastejaram menos tempo no pasto de Brachiaria brizantha, com tempo de 9,75h, enquanto que o pastejo na Brachiaria decumbens foi de 11,3h. Comportamento diferente foi observado para o tempo de ruminação: 6,8 e 6,4 para os pastos de Brachiaria brizantha e Brachiaria decumbens, respectivamente. O número de bocados por minuto foi menor para a Brachiaria decumbens, 31,15, enquanto que, para a Brachiaria brizantha, os bezerros pastejaram com uma taxa de bocados de 34,91 bocados por minuto. Os bezerros tiveram um ganho de peso médio diário superior no pasto de Brachiaria brizantha (390g dia-1, enquanto que, para a Brachiaria decumbens, o ganho diário foi de 340g dia-1.An experiment was carried out to evaluate the ingestive behavior of calves on Brachiaria brizantha and Brachiaria decumbens pastures, under continuous stocking with variable stocking rate. The experimental design was entirely randomized, with two treatments (two pastures, and five replicates per treatment. The experimental period lasted 30 days, consisting of days 20 for adaptation of animals and 10 for behavioral evaluations that consisted of three periods of 24:00h each, in intervals of five days. The calves spent less time grazing Brachiaria brizantha pasture (9,8h than they did on the Brachiaria decumbens (11,3h. Different rumination times had been observed, 6,8 and 6,4 h for the animals grazing Brachiaria brizantha and Brachiaria decumbens

  3. Phytotoxic substance with allelopathic activity in Brachiaria decumbens.

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    Kobayashi, Ai; Kato-Noguchi, Hisashi

    2015-05-01

    The grass Brachiaria decumbens becomes naturalized and quickly dominant in non-native areas. It was hypothesized that phytotoxic substances of plants may contribute to the domination and invasion of the plants. However, no potent phytotoxic substance has been reported in B. decumbens. Therefore, we searched for phytotoxic substances with allelopathic activity in this species. An aqueous methanol extract of B. decumbens inhibited the growth of roots and shoots of cress (Lepidium sativum), lettuce (Lactuca sativa), timothy (Phleum pratense) and ryegrass (Lolium multiflorum) seedlings. The extract was then purified using chromatographic methods and a phytotoxic substance with allelopathic activity was isolated and identified by spectral analysis as (6R,9S)-3-oxo-α-ionol. These results suggest that this compound may contribute to the allelopathic effect caused by the B. decumbens extract and may be in part responsible for the invasion and domination of B. decumbens. Two other Brachiaria species, B. brizantha and a Brachiaria hybrid were also confirmed to contain (6R,9S)-3-oxo-α-ionol. Therefore, this compound may play an important role in the phytotoxicity of the Brachiaria species.

  4. Meiotic analysis in induced tetraploids of Brachiaria decumbens Stapf

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    Carine Simioni

    2011-01-01

    Full Text Available The meiotic behavior of three tetraploid plants (2n=4x=36 originated from somatic chromosome duplication ofsexually reproducing diploid plants of Brachiaria decumbens was evaluated. All the analyzed plants presented abnormalities relatedto polyploidy, such as irregular chromosome segregation, leading to precocious chromosome migration to the poles and micronucleiduring both meiotic divisions. However, the abnormalities observed did not compromise the meiotic products which were characterizedby regular tetrads and satisfactory pollen fertility varying from 61.36 to 64.86%. Chromosomes paired mostly as bivalents indiakinesis but univalents to tetravalents were also observed. These studies contributed to the choice of compatible fertile sexualgenitors to be crossed to natural tetraploid apomicts in the B. decumbens by identifying abnormalities and verifying pollen fertility.Intraespecific crosses should reduce sterility in the hybrids produced in the breeding program of Brachiaria, a problem observedwith the interspecific hybrids produced so far.

  5. Hábito de pastejo de vacas lactantes Holandês x Zebu em pastagens de Brachiaria brizantha e Brachiaria decumbens Grazing behavior of Holstein x Zebu lactating cows in pastures of Brachiaria brizantha and Brachiaria decumbens

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    A.M. Zanine

    2007-02-01

    Full Text Available Avaliou-se o comportamento ingestivo de pastejo de vacas leiteiras em pastagens de Brachiaria brizantha e Brachiaria decumbens, em sistema de lotação contínua com taxa de lotação variável. O delineamento experimental foi o inteiramente ao acaso, com os dois pastos representando os tratamentos, cada um com cinco repetições. O período experimental foi de 30 dias, sendo 20 para adaptação dos animais e 10 para avaliações, em número de três, com duração de 24h cada, em intervalos de cinco dias. O tempo de pastejo da Brachiaria brizantha foi menor, 10,82h, que o tempo de pastejo da Brachiaria decumbens, 12,86h. Comportamento oposto foi observado para o tempo de ruminação, 7,95 e 6,45h para os pastos de Brachiaria brizantha e Brachiaria decumbens, respectivamente. A quantidade de bocados por minuto foi menor na Brachiaria decumbens, 37,30, e maior na Brachiaria brizantha, 42,12. Houve adequação entre os tempos de pastejo, ruminação e taxa de bocados, de modo que o total de bocados e o tempo de ócio não foram diferentes entre os dois pastos.The grazing behavior of lactating cows in pastures of Brachiaria brizantha and Brachiaria decumbens, in system of continuous stocking with variable stocking rate was evaluated. A completely randomized experimental design, with two treatments (pastures and five replicates was used. The experimental period last 30 days, 20 for adaptation of the animals and 10 for three experimental evaluations, of 24h each, in intervals of five days. The grazing time of cows on the Brachiaria brizantha pasture, 10,82h, was lower than on the Brachiaria decumbens, 12,86h. Inverse behavior was observed for rumination time, 7,95 and 6,45h for cows on the pastures of Brachiaria brizantha and Brachiaria decumbens, respectively. The amount of bite per minute was lower for cows on the Brachiaria decumbens, number 37,30h, than on the Brachiaria brizantha, 42,12h. There was an adequacy among grazing time, rumination time

  6. Tiller diversity on Brachiaria decumbens pasture managed under continuos stocking

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    Manoel Eduardo Rozalino Santos

    2011-01-01

    Full Text Available The experiment was carried out aiming to classify and quantify tiller categories of Brachiaria decumbens cv. Basilisk from different heights found on the same pasture. Four different plant heights (10; 20; 30 and 40 cm living at the same pasture were evaluated. Randomized block design with three replications was used. Tillers were classified according to their stage of development, growth origin, defoliation level and size. The number of vegetative tillers reduced linearly, while the number of reproductive tillers and dead tillers increased linearly according to the plant height. The number of aerial tillers showed a quadratic response in relation to the plant height. The pastures having grasses of 10, 20, 30 and 40 cm in height had respectively 292, 408, 496 and 344 aerial tillers/m2. The population density of defoliated tillers reduced linearly according to the plant height. The population density of tillers without the apical shoot showed quadratic response to the signal grass height, being the smallest values found for places having grasses of 10 cm (176 tillers/m2 and 40 cm (180 tillers/m2 in height. The number of tillers without defoliation quadratic responded to the plant height, being the highest values found for places having grasses extremely high. The areas with the highest grasses also showed the highest numbers of tallest tillers. There is indeed a spatial variability of the vegetation and a high morphological diversity of tillers on Brachiaria decumbens cv. Basilisk pastures managed under the continuous stocking system.

  7. Nitrogen loss in Brachiaria decumbens after application of glyphosate or glufosinate-ammonium

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    Damin,Virginia; Franco,Henrique Coutinho Junqueira; Moraes,Milton Ferreira; Franco,Ademir; Trivelin,Paulo Cesar Ocheuze

    2008-01-01

    Nitrogen losses from the soil-plant system may be influenced by herbicide applications. In order to evaluate N loss in brachiaria (Brachiaria decumbens) after application of the herbicides glyphosate and glufosinate-ammonium, an experiment was carried out in a greenhouse as a completely randomized design, with three treatments and six replicates. Treatments were as follows: i) desiccation of brachiaria-plants with glyphosate; ii) desiccation of brachiaria-plants with glufosinate-ammonium; and...

  8. Growth and bromatological characteristics of Brachiaria decumbens and Brachiaria ruziziensis under shading and nitrogen

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    Bruna Moscat Faria

    Full Text Available ABSTRACT This study aimed to evaluate the productive and qualitative characteristics of Brachiaria decumbens and Brachiaria ruziziensis subjected to three levels of artificial shading (0, 36 and 54% and four nitrogen (N doses (0; 50; 100 and 150 mg dm-3 soil, using completely randomized design with a factorial scheme 2 x 3 x 4, with three replications. The dry matter production (DMP, the number of tillers per pot, root weight and crude protein (CP and neutral detergent fiber (NDF contents were evaluated. Both grasses responded quadractly to N, but B. ruziziensis presented greater production under the two highest N doses. The tillers density increased with N dose and was reduced under shading. The root weight increased with N dose, linearly in the full sun and quadractly in the shade. The shading and N showed a positive influence on CP contents. For NDF content, was observed reduction with increase of N dose. The NDF content of B. decumbens increased with shading levels; for B. ruziziensis, the greatest value was observed under intermediate shading level. The N fertilization is an important strategy to improve DMP, tillers density and CP content, for both grasses. However, intense shading should be avoided, as it reduces tillering and root weight, which may threat pasture persistence.

  9. Consórcio de milho e Brachiaria decumbens em diferentes preparos de solo = Maize and Brachiaria decumbens under different soil tillage in farmingpasture integration

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    Simério Carlos Silva Cruz

    2009-10-01

    Full Text Available Preparos conservacionistas e sistemas de produção que visam à maximização sustentável do uso do solo e da água têm surgido como alternativas para regiões caracterizadas por períodos chuvosos relativamente curtos e temperaturas elevadas. O objetivo deste trabalho foi avaliar o sistema de consorciação entre milho e Brachiaria decumbens que melhor se adapte às condições dafoclimáticas da região da Zona da Mata do Estado de Alagoas. Os tratamentos consistiram de um híbrido de milho BRS3150, cultivado nos sistemas: Preparo Convencional, Cultivo Mínimo e Semeadura Direta (BRS3150consorciado com Brachiaria decumbens. O delineamento utilizado foi o de blocos casualisados com parcelas subdivididas. Amostras de solo foram coletadas para análise química. Também foram avaliados os componentes da produção e produtividade de grãos de milho. Os diferentes preparos do solo e a presença de Brachiaria decumbens, no sistema de consócio com milho, não exerceram influência sobre os componentes da produção. Os resultados analisados permitem concluir que a presença da Brachiaria decumbens interferiu negativamente na produtividade dos grãos de milho, quando cultivado em sistema deconsórcio, e as maiores produtividades foram obtidas nos sistemas conservacionistas.Conservation tillage and production systems that aim to maximize soiland water use in a sustainable form have become alternatives for regions that have relatively short periods of rain and high temperatures. The objective of this research was to evaluate intercropping systems with maize and Brachiaria that have better adaptation to the edaphoclimatic conditions of the “Zona da Mata” region, state of Alagoas. The treatments consisted of a BRS 3150 hybrid of maize, cultivated in the following systems: Conventional Cropping, Minimum Cultivation and No-tillage (BRS 3150 intercropped with Brachiaria decumbens. The design used was randomized block with subdivided plots. Soil

  10. Assessing the potential of brachiaria decumbens as remediation agent for soil contaminated wit oil sludge

    International Nuclear Information System (INIS)

    Latiffah Norddin; Ahmad Nazrul Abd Wahid; Hazlina Abdullah; Abdul Razak Ruslan

    2005-01-01

    Bioremediation is a method of treatment of soil or water contaminated with toxic materials, involving the use of living organisms. Oil or petroleum sludge is a waste product of the petroleum refining industry, and is now accumulating at a fast rate at petroleum refinery sites in the country. Common components of oil sludge are mud and sand, containing toxic materials from hydrocarbons, heavy metals and radioactive elements from the seabed. In the present study, the oil sludge samples were obtained from barrels of the materials stored at the Radioactive Waste Treatment Centre, MINT. The samples were analysed of their compounds, elemental and radioactive contents. Trials on microbial degradation of the sludge materials were ongoing. This paper discusses the potential of a grass to remediate soils contaminated with petroleum sludge. Remediation of soils contaminated with organic compounds and heavy metals using plants, including grasses, including Vetiver, Lolium and Agrostis have been carried out in many countries. A greenhouse pot trial was conducted to assess the suitability of the pasture grass Brachiaria decumbens Stapf. and its mutant Brachiaria decumbens KLUANG Comel as a remediation agent for oil sludge contaminated soil. Samples of grasses and soils before planting, during growth stage and at end of experiment were analysed for the different toxicity. Although the grasses were promoted for use in pasture, and KLUANG Comel has good potential as an ornamental plant, too, their other potentials, including as phytoremediation agents need to be explored. (Author)

  11. Liming and plant aging influence on micronutrient uptake by Brachiaria decumbens forage

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    Armelin, Maria Jose A.; Saiki, Mitiko; Primavesi, Odo; Primavesi, Ana C.

    2007-01-01

    Brachiaria decumbens is the main forage in pastures of several Brazilian regions. The effects of liming and plant age on micronutrient uptake by the forage of a degraded Brachiaria decumbens pasture under restoration process, were studied in Sao Carlos - SP, southeastern Brazil, under altitude tropical climate. Experimental design was a random block (100 m 2 ), with 6 replications and 3 treatments. Each block received the following treatment: 0 t/ha of limestone with NK; 2 t/ha of limestone applied on soil surface with NK and maintenance of 1 t/ha per annum; 8 t/ha of limestone applied once on soil surface with NK. Forage samples were collected 14 cm above soil surface, each 36 days in the rain season. Instrumental neutron activation analysis (INAA) followed by gamma-ray spectrometry was the analytical method used to determine the micronutrient content. In some cases, Co Fe, Mn and Zn were negatively affected by increasing limestone doses. The opposite effect was observed for Cl. Decreases of Cl, Co and Mo uptake in forage were enhanced with plant aging. (author)

  12. Acúmulo de forragem em pastos de Brachiaria decumbens adubados com nitrogênio Biomass of the forage in Brachiaria decumbens pastures fertilized with nitrogen

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    Jailson Lara Fagundes

    2005-04-01

    Full Text Available A dinâmica de crescimento de plantas forrageiras tem sido foco de estudo nos últimos anos, visando aprimorar o conhecimento do processo de produção de forragem em pastagens. O objetivo deste trabalho foi avaliar o acúmulo de forragem em pastos de Brachiaria decumbens Stapf. adubados com nitrogênio e submetidos a uma mesma intensidade de pastejo. Os tratamentos consistiram de 75, 150, 225 e 300 kg ha-1 ano-1 de N, aplicados antes do início das avaliações experimentais, as quais foram realizadas durante as estações de verão, outono, inverno e primavera de 2002. O delineamento experimental utilizado foi o de blocos completos casualizados com duas repetições. O capim-braquiária apresentou incremento de produção de matéria seca proporcional às doses de nitrogênio. Observaram-se maiores valores de taxa de acúmulo de folha, colmo e forragem nas estações primavera-verão e valores menores no inverno. As variações nas condições climáticas com as estações do ano alteraram as taxas de acúmulo de folha e colmo, senescência e de produção de forragem em Brachiaria decumbens.In the last years, the growth dynamics of forage plants has been focused, in order to improve the knowledge of forage yield and distribution process in pasture. The objective of this work was to evaluate the effect of nitrogen fertilization on accumulation of the forage in Brachiaria decumbens Stapf. pastures submitted to the same stocking rate. Treatments consisted of 75, 150, 225 and 300 kg ha-1 yr-1 N applied before the beginning of experimental evaluations, which were performed during summer, autumn, winter and spring of 2002. A randomized block experimental design was used with two replicates. Brachiaria grass showed an increase in the dry matter yield proportionally to nitrogen doses, with higher rates for daily accumulation of leaves, stems and forage yield in summer-spring seasons, while lower rates were shown in the winter. The variation of

  13. Influence of limestone doses in the Manganese absorption by Brachiaria decumbens

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    Armelin, Maria Jose A.; Fulas, Paulo M.M.; Saiki, Mitiko; Primavesi, Odo; Primavesi, Ana C.

    2005-01-01

    To restore a degraded pasture of Brachiaria decumbens, located in Sao Carlos - SP, Southeastern Brazil, under tropical climate, an experiment was carried out to study the influence of different methods of the limestone doses application on manganese absorption by the aboveground part of the forage, during 3 years of treatment. The experimental design was randomized block, with 6 replications and 8 treatments. The 100m 2 blocks were established in the pasture. Each block received a sequence of limestone doses (0, 1, 2, 4, and 8 t/ha) applied on soil surface with NK and, 2 t/ha applied on soil surface with plus one annual application of 1t/ha and NK, 4t/ha buried in the soil with NK, 4t/ha applied on soil surface without NK. Forages samples were collected 14 cm above soil surface. Instrumental neutron activation analysis (INAA) followed by gamma-ray spectrometry was the analytical method used to determine manganese content. The statistical analysis showed some significant variations of this element absorption by the plant with regard to the treatments, but anything that could compromise the mineral nutrition of forage. Moreover, the quality of forage for the animal feeding showed suitable agreement to manganese requirement. INAA showed that it can be an alternative option for agronomical researches that require the knowledge of the manganese concentration. (author)

  14. Different supplents for finishing of Nellore cattle on deferred Brachiaria decumbens pasture during the dry season

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    Antonio Tadeu de Andrade

    2015-07-01

    Full Text Available This study evaluated the effect of four types of supplement on the finishing of Nellore cattle on deferred Brachiaria decumbens pasture during the dry season. Sixty-four castrated Nellore males with an age of approximately 34 months and initial body weight (BW ranging from 360 to 380 kg were divided into 16 animals per treatment in a completely randomized design. The treatments consisted of four types of pasture supplement: deferred Brachiaria decumbens pasture + energy protein mineral salt (SuEPM used as control; deferred Brachiaria decumbens pasture + urea + cottonseed meal (28% CP + ground corn grain (SuCo; deferred Brachiaria decumbens pasture + urea + cottonseed meal (28% CP + citrus pulp (SuCPu; deferred Brachiaria decumbens pasture + urea + cottonseed meal (28% CP + soy hull (SuSH. The pasture was deferred for 170 days and provided 3,482 kg DM/ha of forage, permitting a stocking rate of 1.56 AU/ha (DM intake of 2.25% BW and 50% pasture efficiency. The animals received the supplement ad libitum in the SuEPM treatment and as % BW in the other treatments from July to October. The animals were slaughtered at a minimum BW of 457 kg. The following variables were evaluated: final weight, weight gain during the period (WG, average daily gain (ADG, hot carcass weight (HCW, and hot carcass yield (HCY. With respect to final weight, the supplement in the SuCo, SuCPu and SuSH treatments permitted a greater supply of nutrients and the animals therefore exhibited better performance (P<0.05 compared to the SuEPM treatment (mean of 478.68 vs 412.62 kg. The same effect was observed for the other parameters studied. Analysis of WG and ADG showed that SuSH was superior to the SuCo and SuCPu treatments (P<0.05 due to the increased offer of concentrate and SuEPM was inferior to the other treatments. Higher HCW (260.05 kg and HCY (53.92% were obtained with treatment SuSH as a result of greater performance. Supplementation of cattle during the dry period on

  15. Estoque de serapilheira e fertilidade do solo em pastagem degradada de Brachiaria decumbens após implantação de leguminosas arbustivas e arbóreas forrageiras Soil litter stock and fertility after planting leguminous shrubs and forage trees on degraded signal grass pasture

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    André Barbosa Silva

    2013-04-01

    Full Text Available As pastagens formam a base da pecuária brasileira; essas sofrem degradação em larga escala por deficiência de nitrogênio (N. O consórcio com leguminosas, além de fixar N, pode apresentar outros efeitos na fertilidade do solo como acidificação ou retirada de nutrientes de camadas mais profundas para as mais superficiais. Este trabalho objetivou avaliar o estoque de serapilheira e a fertilidade do solo em pastagens degradadas de braquiária (Brachiaria decumbens, após implantar leguminosas arbustivas e arbóreas forrageiras. Para isso, uma amostragem foi realizada em março de 2010 em um experimento no campo, introduzindo pastagem degradada de Brachiaria decumbens, em julho de 2008, com sabiá (Mimosa caesalpiniifolia, leucena (Leucaena leucocephala, mororó (Bauhinia cheilantha e gliricídia (Gliricidia sepium, além de braquiária adubada e não adubada com N. As amostras de solo e serapilheira foram coletadas aos 0-10, 10-20 e 20-40 cm de profundidade, em três transectos, alternando pontos cobertos por gramíneas e leguminosas, totalizando sete amostras compostas por parcela para determinar pH, P, K, Ca, Mg e Al no solo, enquanto SB, t e m foram calculados. A serapilheira foi separada visualmente em leguminosas, gramíneas e materiais não identificados, em que foram utilizados para quantificação de matéria seca, matéria orgânica, N, P, C, fibra detergente ácido e lignina. A introdução das leguminosas aumentou os teores de N total na serapilheira e reduziu as relações C:N, com destaque para gliricídia e sabiá; entretanto, essa última apresentou elevados teores de lignina. Houve efeito significativo da cobertura por leguminosas, sem diferenças entre essas, para pH e K, na profundidade de 0-10 cm, e para Al e m, aos 10-20 cm de profundidade.Pastures are the fodder supply of Brazilian livestock, and are exhaustively degraded by nitrogen (N deficiency. Intercropping with legumes, aside from nitrogen fixation, may have

  16. SULPHUR DEFICIENCY IN DAIRY CALVES REARED ON PASTURE OF Brachiaria decumbens DEFICIÊNCIA DE ENXOFRE EM BEZERROS LEITEIROS MANTIDOS EM PASTAGEM DE Brachiaria decumbens

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    Enrico Lippi Ortolani

    2001-04-01

    Full Text Available The clinical picture of sulphur (S deficiency is described by the first time in Brazilian dairy calves. Twelve crossbred six-month-old weaned dairy calves, reared on pasture of S-deficient Brachiaria decumbens, were used. The calves were randomly assigned in two groups of six calves each to verify the influence of S supplementation on some clinical and serum biochemical variables. All animals were fed a basal-supplement mix containing macro and microlements, urea and ground corn grain added (41gS/kg or not of S (elemental S; 1g S/kg, for six months. At the end of the experiment, the S-supplemented calves had higher mean body weight (p São descritos, pela primeira vez no Brasil, os sinais clínicos de bezerros leiteiros com deficiência de enxofre (S. Doze bezerros mestiços, recém-desmamados e com seis meses de idade, foram distribuídos, ao acaso, em dois grupos iguais. Todos os animais pastejaram em piquetes de Brachiaria decumbens e receberam, por seis meses, um suplemento básico contendo macro e microelementos, uréia e fubá, contendo 1gS/kg. No segundo grupo, essa mistura era suplementada com S-elementar para conter 41gS/kg. Ao término do experimento, o grupo suplementado com S apresentou um maior ganho de peso (p < 0,01, melhor condicão corporal (p < 0,016, e maiores concentrações séricas de sulfato inorgânico (p < 0,001 e de albumina ( p < 0,01 que os bezerros não suplementados. Os animais deficientes em S apresentaram perda de condição corporal, retardo de crescimento, perda de peso e discreta apatia.

  17. Allelopathic evidence in Brachiaria decumbens and its potential to invade the Brazilian Cerrados

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    Elizabeth Gorgone Barbosa

    2008-08-01

    Full Text Available The aim of this study was to look for evidence of allelochemicals in B. decumbens, in parts of the plant from where they could easily be released to the environment. The germination inhibition of Phalaris canariensis, Lactuca sativa (standard species and Melinis minutiflora, another invasive African grass, was tested using B. decumbens germinating seeds and aqueous leachates of the roots, green and senescent leaves, at 5, 10 and 20% w/v. Both the germinating seeds and the aqueous leachates of B. decumbens reduced the germination of the species tested; the effectiveness of the aqueous leachates increased according to concentration. Apparently, the competitive advantage of B. decumbens in the cerrados could be amplified via allelopathy.Invasão biológica é uma das maiores causas atuais da perda de biodiversidade. Várias espécies que se tornam invasoras produzem substâncias fitotóxicas que aumentam sua capacidade competitiva; assim, a alelopatia é uma estratégia capaz de potencializar o sucesso de invasão. Brachiaria decumbens, uma gramínea africana, invadiu os cerrados brasileiros e representa, atualmente, uma séria ameaça à biota regional. Neste ensaio, verificamos a presença de aleloquímicos em partes de B. decumbens das quais poderiam ser facilmente liberados para o ambiente. Testamos a inibição da germinação de Phalaris canariensis, Lactuca sativa (espécies padrão e Melinis minutiflora (outra gramínea africana invasora usando sementes de B. decumbens e soluções aquosas lixiviadas de suas raízes, folhas verdes e folhas senescentes, a 5, 10 e 20% de peso do material por volume de água. Tanto as sementes como as soluções lixiviadas de decumbens reduziram a germinação das outras espécies; a eficiência dos lixiviados aumentou de acordo com a concentração da solução. Acreditamos que a grande vantagem competitiva de B. decumbens no cerrado possa ser amplificada pela alelopatia.

  18. Effect of liming and fertilizer on mineral content and productivity of Brachiaria Decumbens grass forage

    International Nuclear Information System (INIS)

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

    2007-01-01

    To restore a degraded pasture of Brachiaria decumbens, located in Sao Carlos - SP, southeastern Brazil, under altitude tropical climate, an experiment was carried out to study the effects of limestone, buried or not buried in the soil, and fertilizer use on mineral content and forage yield, after 3 years of treatment. Limestone and phosphorus were applied once, one month before starting. NK were applied after each cutting, for fertilized plots, four to five times a year. Experimental design was a random block (100 m 2 ), with 6 replications and 4 treatments. Each block received 4 t/ha of limestone, except the control. Forage samples were collected 14 cm above soil surface. Instrumental neutron activation analysis (INAA) followed by gamma-ray spectrometry was the analytical method used to determine the mineral contents. Dry matter yield was affected positively with liming when compared with the limestone control, but the effect of limestone use was more pronounced with the concomitant use of NK fertilizer. The contents of Ca, Cs, Fe, La, Mg, Rb, Sc, Sm and Th in forage were negatively affected with the NK use, perhaps due to a dilution effect, while a reverse were observed for K, Cl, perhaps due to input of KCl, besides Br, Mn and Se. It seems that limestone is not a key input to restore degraded tropical pastureland, grown on acid soils, when nitrogen is lacking. INAA allowed the monitoring of some not routine elements that may be under observation to avoid potential plant nutritional disorders in production systems with high limestone and fertilizer use. (author)

  19. Ecophysiological and anatomical changes due to uptake and accumulation of heavy metal in Brachiaria decumbens

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    Marcelo Pedrosa Gomes

    2011-10-01

    Full Text Available The growth and developmental characteristics of grasses and their high biodiversity make such plants suitable for remediation of areas contaminated by heavy metals. Nevertheless, heavy metal toxic effect on the plants may cause alteration in their metabolic pathways, such as photosynthesis, respiration, and growth, modifying plant anatomy. This work aimed to evaluate the effect of levels of soil contamination (0, 7.5 % and 15 % m³ m-3 on biomass production, on photosynthetic characteristics and on anatomical changes in roots and leaves of brachiaria (Brachiaria decumbens Stapf.. After seeds were planted, seedlings were uprooted and replanted in vases containing soil at different contamination levels, being left to rest for 120 days. At the end of that time, plants presented reduced yield of root and shoot dry matter, contents of chlorophyll a, chlorophyll b, total chlorophyll and potential photosynthesis with increased of soil contamination. The cell layers of endodermis and exodermis in the root tissues and the cell walls of the xylem and cortical parenchyma all thickened as contamination increased. In the leaf tissues, the adaxial and abaxial epidermis presented increased thickness while the leaf blade presented reduced thickness as contamination increased with consequent change in the root growth rate. In general, the effects of heavy metal increased with the metal concentration. Some results indicate that B. decumbens seems to have some degree of heavy metal tolerance.

  20. SISTEMAS DE MANEJO DO SOLO: SOJA [Glycine max (L.] CONSORCIADA COM Brachiaria decumbens (STAPF SOIL MANAGEMENT SYSTEMS: SOYBEAN [Glycine max (L.] INTERCROPPED WITH Brachiaria decumbens (STAPF

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    Emanuel da Silva Barros

    2011-01-01

    vagem, número de grãos por planta, massa de 1.000 grãos e produtividade; e 2 B. decumbens: composição química das plantas, além do acúmulo de matéria seca, em cinco épocas de amostragens. Os sistemas de manejo do solo influenciaram o estande de plantas e a concentração de P, Cu, Fe e Zn, na soja, além do S, na Brachiaria decumbens. O sistema plantio direto apresentou maior produtividade de grãos e produção de fitomassa de B. decumbens, nas condições edafoclimáticas de Rio Largo (AL.

    PALAVRAS-CHAVE: Plantio direto; integração lavoura-pecuária; cultivo mínimo.

    The aim of this study was to evaluate the effects of different soil management systems on the soybean yield components intercropped or not with Brachiaria

  1. Perdas de nitrogênio por Brachiaria decumbens após a aplicação de glifosato ou glufosinato de amônio

    OpenAIRE

    DAMIN, Virginia; FRANCO, Henrique Coutinho Junqueira; MORAES, Milton Ferreira; FRANCO, Ademir; TRIVELIN, Paulo Cesar Ocheuze

    2008-01-01

    Nitrogen losses from the soil-plant system may be influenced by herbicide applications. In order to evaluate N loss in brachiaria (Brachiaria decumbens) after application of the herbicides glyphosate and glufosinate-ammonium, an experiment was carried out in a greenhouse as a completely randomized design, with three treatments and six replicates. Treatments were as follows: i) desiccation of brachiaria-plants with glyphosate; ii) desiccation of brachiaria-plants with glufosinate-ammonium; and...

  2. The possible allelopathic effects of Brachiaria decumbens on initial development of root stock of Citrus limonia

    OpenAIRE

    Souza, L. S.; Velini, E. D.; Martins, D.; Rosolem, C. A.

    1997-01-01

    Foram estudados os possíveis efeitos alelopáticos da incorporação da matéria seca da parte aérea de Brachiaria decumbens, ao substrato, nas concentrações de 0, 1,5 e 3,0% (p/p) sobre o crescimento inicial de limão cravo (Citrus limonia Osbeck), em casa-de-vegetação. Foram determinados os parâmetros biométrico s e algumas propriedades físico-químicas da solução do solo. A maior quantidade de matéria seca incorporada causou redução de 44, 42, 57 e 55% das médias da altura, teor de clorofila, ár...

  3. PRODUÇÃO E COMPOSIÇÃO QUÍMICA DA Brachiaria brizantha E Brachiaria decumbens SUBMETIDAS A DIFERENTES ADUBAÇÕES PRODUCTION AND CHEMICAL COMPOSITION OF Brachiaria brizantha AND Brachiaria decumbens SUBMITTED TO DIFFERENT FERTILIZATION

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    Neusete Maria da Silva Patês

    2008-12-01

    Full Text Available Objetivou-se, com este trabalho, avaliar a produção e a composição química de dois cultivares de braquiária com diferentes adubações. Instalou-se o experimento em casa de vegetação no Campus Juvino Oliveira pertencente à UESB, localizado na cidade de Itapetinga, BA. O ensaio foi desenvolvido em esquema fatorial 2x5, sendo dois cultivares de Brachiaria (B. brizantha cv. marandu e B. decumbens cv. basilisk e cinco adubações (sem adubo, N, P, NP e NK, mediante a utilização de 50 kg.ha-1 de P, 30 kg.ha-1 de K e 300 kg.ha-1 de N como nutrientes. O delineamento adotado foi inteiramente ao acaso, com quatro repetições. Utilizaram-se vasos plásticos com 30 cm de diâmetro por 22 cm de altura e capacidade de 10 dm3. Efetuaram-se três coletas de amostras da parte aérea, sendo cada período correspondente a 28 dias de crescimento da planta. Procedeu-se à coleta dessas amostras e secagem destas em estufa, sendo depois moídas a 1 mm. Posteriormente, fez-se uma amostra composta. Os resultados demonstram que a interação entre os cultivares e a adubação foi significativa para produção de massa seca da parte aérea e cinzas. O cultivar basilisk mostrou-se superior em relação ao cultivar marandu na maioria das variáveis analisadas. Os valores encontrados para a composição química dos cultivares em estudo estão de acordo com os valores tabelados para gramíneas com rebrota de 28 dias.

    PALAVRAS-CHAVES: Baquiária, proteína bruta, raízes. The objective of this work was to evaluate the production and chemical composition of two cultivates of Brachiaria with different fertilizations. The experiment was installed in a green house at Juvino Oliveira Campus of UESB, in Itapeting, BA. The assay was conducted in a 2x5 factorial scheme, being two cultivates of Brachiaria (B. brizantha cv. marandu and B. decumbens cv. basilisk and five fertilizations (without fertilizer, P, N, NP and NK. The quantity of nutrients used was 50 kg

  4. STRUCTURE AND NUTRITIVE VALUE OF DEFERRED PASTURE OF BRACHIARIA DECUMBENS CV. BASILISK DURING THE GRAZING PERIOD

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    Manoel Eduardo Rozalino Santos

    2011-07-01

    Full Text Available The experiment aimed to understand the effect of grazing period on morphology and nutritive value of deferred Brachiaria decumbens cv. Basilisk pasture and on hand-plucking sample with cattle. Subdivided plots were used according to a randomized block design with two replicates. Four grazing periods (1, 31, 57 and 88 days and two forage samples (available in pasture (AP and obtained by hand-plucking (HP were studied. The live leaf laminae (LLL, potentially digestible neutral detergent fiber (PDNDF, potentially digestible dry matter (PDDM and crude protein (CP levels were higher and dead leaf laminae (DLL, and dead stem (DS, neutral detergent fiber (NDF and indigestible NDF percentages were lower in sample of HP in relation to forage AP. The grazing period decreased linearly the LLL, PDNDF, PDDM percentages, as well as increased linearly DS and indigestible NDF levels in forages. The potential selectivity indexes (PSI of LLL and indigestible NDF increased linearly with grazing period. The PSI of live stem was smaller and the PSI of CP was higher in interim periods of grazing. The reduction in deferring period results in B. decumbens with better morphological composition and nutritional value, which favors the animal selectivity.

  5. Spatial variability of forage yield and soil physical attributes of a Brachiaria decumbens pasture in the Brazilian Cerrado

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    Cristiano Magalhães Pariz

    2011-10-01

    Full Text Available The objective of this study was to analyze variability, linear and spatial correlations of forage dry mass yield (FDM and dry matter percentage (DM% of Brachiaria decumbens with the bulk density (BD, gravimetric (GM and volumetric (VM moisture, mechanical resistance to penetration (RP and organic matter content (OM, at depths 1 (0-0.10 m and 2 (0.10-0.20 m, in a Red Latosol (Oxisol, in order to select an indicator of soil physical quality and identify possible causes of pasture degradation. The geostatistical grid was installed to collect soil and plant data, with 121 sampling points, over an area of 2.56 ha. The linear correlation between FDM × DM% and FDM × BD2 was low, but highly significant. Spatial correlations varied inversely and positively, respectively. Except for DM% and BD, at both depths, the other attributes showed average to high variability, indicating a heterogeneous environment. Thus, geostatistics emerges as an important tool in understanding the interactions in pasture ecosystems, in order to minimize possible causes of degradation and indicate better alternatives for soil-plant-animal management. The decrease in FDM and increased BD1 are indicators of physical degradation (compaction of Red Latosol (Oxisol, particularly in the places with the highest concentration of animals and excessive trampling, in Cerrado conditions, in the municipality of Selvíria, Mato Grosso do Sul State, Brazil.

  6. CALCIUM SOURCE EFFECT ON APPARENT DIGESTIBILITY OF GRASS HAY Brachiaria decumbens Staph cv. Basiliski EFEITO DA FONTE DE CÁLCIO (calcário vs Lithothamnium calcareum) NA DIGESTIBILIDADE APARENTE DE CAPIM Brachiaria decumbens Staph cv. Basiliski

    OpenAIRE

    Deborah Gonçalves Rodrigues; Clizeide R. Oliveira; Benir de Oliveira; Celso de Paula Costa; Geisa Fleury Orsine

    2007-01-01

    An experiment was developed to determine the effect of addition of the marine alga Lithothamnium calcareum in the apparent digestibility of a low quality forage. Twelve adult lambs were kept in metabolical individual cages using a randomly design with three replications and four treatments as follows: I - Brachiaria decumbens grass hay, processed after the seed harvest; II - Hay plus 1000 ppm of calcium from CaCO3 ...

  7. Losses through gases and effluent and nutritional value of Brachiaria decumbens with addition of soybean hulls

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    Carlos Clayton Oliveira Dantas

    2014-05-01

    Full Text Available The objective of this experiment was to evaluate the losses of nutrient through gases and effluents, the nutrient recovery, fermentation parameters and the chemical parameters of silages of Brachiaria decumbens with the addition of soybean hulls, testing five levels of inclusion: 0, 10, 20, 30 and 40% (as is, with five replications per treatment. After the standardization cut of the forage, performed at 5 cm from the soil level, the soil was fertilized with nitrogen and potassium in the form of ammonium sulfate and potassium chloride, respectively, at 60 kg/ha. After 60 days, the grass was cut at 10 cm from the soil and ensiled. Experimental silos with capacity of 10 liters with Bunsen valve were used. Silos had 3 kg of sand conditioned at the bottom for retention of the effluents. The results show that the contents of dry matter, crude protein, acid detergent insoluble fiber and total digestible nutrients presented positive linear behavior with the inclusion of soybean hulls. In the grass silages with addition of soybean hulls, there was greater recovery of dry matter in relation to the control silage, which is a reflection of the negative linear behavior for the values of losses of gases and effluent. There was quadratic behavior in the pH values and negative linear behavior for the ammonia N values and buffering capacity with the inclusion of the additive in the grass silage. Inclusion of soybean hulls is sufficient to improve the fermentation pattern and minimize the losses through gases and effluents, contributing to the nutrient recovery, in addition to promoting overall improvement of the nutritional value of Brachiaria grass silages.

  8. Efeito alelopático de capim-braquiária (Brachiaria decumbens sobre o crescimento inicial de sete espécies de plantas cultivadas Allelopathic effects of Brachiaria decumbens on the initial development of seven crops

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    L.S. Souza

    2006-12-01

    Full Text Available O presente trabalho constou de sete experimentos, que foram conduzidos na Faculdade de Ciências Agronômicas, campus de Botucatu, UNESP, São Paulo, Brasil, com o objetivo de avaliar os efeitos alelopáticos de Brachiaria decumbens, colhida em diferentes épocas, sobre o crescimento inicial de milho, arroz, trigo, soja, feijão, algodão e capim-braquiária (B. decumbens, bem como a dinâmica do nitrogênio no solo. A parte aérea de B. decumbens foi coletada durante as estações seca (outono-inverno e chuvosa (primavera-verão, em área de pastagem localizada no município de Botucatu-SP. A matéria seca triturada de B. decumbens foi incorporada ao solo dos vasos na proporção de 3% p/p. O delineamento experimental foi inteiramente casualizado, com cinco repetições. Contando-se a partir do transplante, o experimento foi conduzido por 21 dias para milho e feijão, 24 dias para soja e trigo, 28 dias para arroz e 30 dias para algodão e capim-braquiária. O crescimento dessas plantas foi reduzido com a adição de capim-braquiária para as duas épocas, sendo o próprio capim-braquiária o mais afetado. Os efeitos inibitórios foram mais intensos para capim-braquiária coletado na estação chuvosa. A incorporação da matéria seca da parte aérea de B. decumbens reduziu, significativamente, os teores de nitrato no solo, em todos os estudos realizados.This work consisted of seven experiments carried out at UNESP Botucatu-SP Brazil to evaluate the allelopathic effects of Brachiaria decumbens collected in different seasons on the initial growth of corn, rice, wheat, soybean, bean, cotton and B. decumbens and to evaluate nitrogen dynamics in the soil. The upper part of B. decumbens was collected during the dry and wet seasons in a pasture area located in the district of Botucatu-SP. The dry matter was ground and incorporated into the soil in 3% w/w. The experimental design was arranged in completely randomized plots with 5 replications

  9. DENDROMETRY CHARACTERISTICS OF EUCALYPTUS UROPHYLLA IN SILVOPASTORAL SYSTEM UNDER DIFFERENT PLANTING SPACINGS WITH BRACHIARIA DECUMBENS

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    Raphael Pavesi Araujo

    2011-12-01

    Full Text Available The objective of this study was to evaluate the effect of spacing on eucalyptus dendrometric characteristics in silvopastoral system with Brachiaria decumbens. Three eucalyptus spacing were used (3x2, 6x4 and 10x4 m. The randomized block design was used with factorial scheme (3x4 with three densities of planting eucalyptus (3x2, 6x4 and 10x4 m and four times of evaluation (6, 12, 18 and 24 months after planting. The dendrometric characteristics were evaluated: 0,30 m diameter, diameter at breast height - 1.30 m (DBH, cup diameter, height, biomass per tree and plant survival. It was found positive effect of months of evaluation for the diameter to 0.30 m, cup diameter and height. There were no effects of spacing for the variables DBH, survival and biomass per tree when evaluated at 24 months. There was effect for biomass per hectare being 3x2 m the best treatament. It can be concluded that the planting spacing only affected the biomass per hectare, when evaluated up to 24 months of Eucalyptus urophylla grown in silvopastoral system.

  10. EFFECT OF DIESEL AND BIODIESEL ON THE GROWTH OF Brachiaria decumbens INOCULATED WITH ARBUSCULAR MYCORRHIZAL FUNGI

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    Dora Trejo

    2013-12-01

    Full Text Available Arbuscular mycorrhizal fungi have been found to be associated with plants useful in soil phytoremediation. The aim of this study was to compare the effects of diesel and biodiesel in soil and sand on the growth of Brachiaria decumbens inoculated with mycorrhizae. Two experiments were carried out: one experiment in soil and another in sand. A two-level- factorial design with three factors was used (one on sterile and another on non-sterile soil, with and without mycorrhizae; and one with diesel and another with biodiesel. In sand, a two-factor design with two levels was used (with and without mycorrhizae and with diesel and biodiesel, both with three replications. NOVADIESEL, biodiesel and PEMEX diesel were use as contaminants, both at 7%. The fresh and dry weight of the plants and percentage of mycorrhizal colonization, were assessed 30 days after planting. In soil, biodiesel was more toxic and reduced the fresh and dry weights of plants, especially in non-sterile soil. Biodiesel yielded greater mycorrhizal colonization values that doubled those of the control. In sand, diesel was found to reduce three times the fresh and dry weights of plants, compared to the biodiesel. In sand diesel presented high values of mycorrhizal colonization in comparison with biodiesel.  Plants inoculated with mycorrhizal fungi exhibited better development than non-inoculated plants, even in the presence of contaminants.

  11. Clinical and histopathological study of the phototoxic dermatitis in Zebu calves in grazing of Brachiaria decumbens

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    José Cardona-Álvarez

    2016-05-01

    Full Text Available Objective. The objective was to study the clinical and histopathological aspects of Phototoxic Dermatitis Secondary (PDS, secondary to ingestion of Brachiaria decumbens in Zebu calves (Bos indicus department of Cordoba, Colombia. Materials and methods. Twelve calves Zebu, male, 12 to 18 months, PDS diagnosed with clinical, histopathologically studied and laboratory exams. Results.Clinically, signs of photophobia, dehydration, progressive emaciation, icteric mucous membranes and skin lesions as res-breaking with leathery skin appearance, skin peeling and scabbing over large areas were evident. The lesions were located bilaterally in different areas of the skin in ears, perineal region, epigastric and costal. Serological tests gave the high catalytic activity of the liver enzymes AST and GGT indicating liver injury consistent with cholestasis. Histopathologically was observed in hematoxylin eosin, chronic necrotic dermatitis, in trichrome Gomori poor dermal proliferation disorganized fibroblasts, low presence of diffuse connective tissue and collagen fibers disorganized and picrosirius red / polarization areas reddish birefringence was observed was observed and greenyellow, indicating moderate presence of mature collagen type I (bright red in polarization and Type III (bright yellowish-green polarization. Conclusions. The definitive diagnosis of the disease was based on clinical features, laboratory findings and histopathological findings, being conclusive as diagnostic methods of the PDS. In the literature there are no reports of studies PDS in Zebu calves department of Córdoba and Colombia.

  12. Possíveis efeitos alelopaticos de Brachiaria decumbens sobre o crescimento inicial de limão cravo (Citrus limonia The possible allelopathic effects of Brachiaria decumbens on initial development of root stock of Citrus limonia

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    L. S. Souza

    1997-01-01

    Full Text Available Foram estudados os possíveis efeitos alelopáticos da incorporação da matéria seca da parte aérea de Brachiaria decumbens, ao substrato, nas concentrações de 0, 1,5 e 3,0% (p/p sobre o crescimento inicial de limão cravo (Citrus limonia Osbeck, em casa-de-vegetação. Foram determinados os parâmetros biométrico s e algumas propriedades físico-químicas da solução do solo. A maior quantidade de matéria seca incorporada causou redução de 44, 42, 57 e 55% das médias da altura, teor de clorofila, área foliar e acúmulo de matéria seca total, respectivamente. O potencial osmótico, pH, condutividade elétrica e os teores de nutrientes da solução do solo foram alterados. Provavelmente, a redução do crescimento observada seja devida a deficiência de N causada por alterações na dinâmica do N-solo em função da incorporação de B. decumbens.It was studied the possible allelopathic effect of Brachiaria decumbens on initial development of Citrus limonia in greenhouse. The dry matter was incorporated into the soil in 0, 1,5, 3,0% (w/w-proportion. Biometric parameters and physic propert ies of soil were determined by soil solutio n. Greatest propotion reduced all the biometric parameters analyse d. Physical properties of nutrient levels (except N of soil did not observed significantly alterations. Greatest proportion reduced the average stem diameter of Citrus limonia at 57%. Probably, these results were due to lack in nitrogen level observed in soil solution.

  13. Épocas de manejo químico de Brachiaria decumbens antecedendo o plantio direto de soja Brachiaria decumbens management times in soybean under no tillage system

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    A.S. Nunes

    2009-06-01

    Full Text Available O manejo químico da cobertura vegetal e a manutenção da palhada sobre o solo são preocupações comuns para os produtores que adotam o sistema plantio direto na região dos cerrados. Com o objetivo de estudar a influência da época de manejo químico de B. decumbens sobre o desenvolvimento e a produtividade da cultura da soja em sistema plantio direto, foram realizados dois ensaios a campo, respectivamente, com os cultivares BRS 154 e MG/BR 46-Conquista, no ano de 2003. Em cada ensaio, testaram-se quatro épocas de manejo de B. decumbens antecedendo a semeadura da soja (28, 14, 7 e 0 dias, utilizando-se o herbicida glifosato. Os ensaios foram conduzidos em delineamento inteiramente casualizado, utilizando-se três repetições no primeiro e quatro no segundo. Determinou-se a matéria seca da cobertura vegetal e avaliou-se a reinfestação de B. decumbens. Na cultura da soja, foram determinados: altura de inserção da primeira vagem, número de vagens por planta, umidade dos grãos, massa de 100 grãos e produtividade. Com base nos resultados obtidos, conclui-se que a época mais adequada para o manejo químico de B. decumbens com glifosato situa-se entre 7 e 14 dias antes da semeadura da cultura da soja e que a escolha da época de manejo químico da cobertura vegetal afeta de forma decisiva o desenvolvimento e a produtividade da cultura.Cover crop management and straw maintenance over the soil are common concerns for producers adopting the no tillage system in the cerrado region in Brazil. In order to study the influence of B. decumbens time management on soybean development and productivity under no tillage system, two assays were carried out using the cultivars BRS 154 and MG/BR 46-Conquista. For each cultivar, four B. decumbens management times prior to sowing of soybean (28, 14, 7 and 0 days were tested using glyphosate for weed control, in three replicates for cultivar BRS 154 and four replications for MG/BR 46-Conquista, in a

  14. Uptake of heavy metals by Brachiaria Decumbens and its mutant as a remediation agent for soil contaminated with oil sludge

    International Nuclear Information System (INIS)

    Ahmad Nazrul Abd Wahid; Latiffah Noordin; Abdul Razak Ruslan; Hazlina Abdullah; Khairuddin Abdul Rahim

    2006-01-01

    The Malaysian petroleum industry produces thousands of tonnes of oil sludge per year. Oil sludge is the residue accumulated during processing of petroleum at petroleum processing plants. Besides soil, mud and sand, oil sludge is often rich in radioactive substances, heavy metals and other toxic materials from hydrocarbon group which could contaminate and environment. In the present study the pasture grass Brachiaria decumbens and its mutant B. decumbens Kluang Comel were evaluated on their effectiveness as remediation agents for contaminated soils. The contaminating agent tested was the oil sludge with its hydrocarbons vaporised, obtained from the Waste Management Centre, MINT. Amongst the indicators for an effective remediation agent is the ability to accumulate heavy metals in their tissues without affecting their growth. This trial was conducted at MINT glasshouse, whereby the test plants were planted in pots in soil added with vaporised oil sludge. Analysis of heavy metals was through Inductive Coupled Plasma Mass Spectrometry (ICPMS) and Neutron Activation Analysis (NAA). This paper discusses the accumulation of heavy metals by B. decumbens and its mutant Kluang Comel and their growth performance, hence assessing their suitability as remediation agent in soil contaminated with oil sludge. (Author)

  15. Crystal-associated cholangiopathy in sheep grazing Brachiaria decumbens containing the saponin protodioscin Colangiopatia associada a cristais em ovinos alimentados com Brachiaria decumbens que contém a saponina protodioscina

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    Karine B. Brum

    2007-01-01

    Full Text Available An outbreak of hepatogenous photosensitization is reported in a flock of 28 sheep grazing Brachiaria decumbens in Mato Grosso do Sul State, Central-Western Brazil. Seven lambs and an adult sheep were affected and 6 of them died. Two surviving affected lambs and one lamb without clinical signs had increased serum values of gamma glutamyltransferase, bilirubin, and cholesterol. In two adult unaffected sheep those parameters were within normal values. An adult sheep submitted to necropsy presented moderate body condition, unilateral corneal opacity, drying of the muzzle, moderate jaundice, increased lobular pattern of the liver, and a distended gallbladder. Histological lesions were epithelial degeneration, necrosis, and hyperplasia of small bile ducts. Mild amounts of foamy macrophages were observed, mainly in the centroacinar zone. Diffuse swelling and vacuolation were observed in hepatocytes. Crystal negative images were found within bile ducts, foamy macrophages, and the lumen of some renal tubules. The heart showed multifocal areas of degeneration and necrosis of the muscle fibers. Pasture samples (Brachiaria decumbens contained 2.36% of protodioscin. No Pithomyces chartarum spores were found in the pasture. Samples from a similar neighboring B. decumbens pasture grazed by cattle without photosensitization contained 1.63% of protodioscin isomers. Outbreaks of photosensitization caused by Brachiaria spp. are common in cattle in the Brazilian Cerrado (savanna with about 51 million hectares of Brachiaria spp pastures. Sheep farming has been recently developed in this region, and the number of sheep is increasing significantly. Because sheep are more susceptible than cattle to lithogenic saponins, poisoning by Brachiaria should be an important limiting factor for the sheep industry.Um surto de fotossensibilização hepatógena é descrito em um rebanho de 28 ovinos mantidos em pastagem de Brachiaria decumbens no Estado de Mato Grosso do Sul, regi

  16. Nitrogen loss in Brachiaria decumbens after application of glyphosate or glufosinate-ammonium Perdas de nitrogênio por Brachiaria decumbens após a aplicação de glifosato ou glufosinato de amônio

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    Virginia Damin

    2008-01-01

    Full Text Available Nitrogen losses from the soil-plant system may be influenced by herbicide applications. In order to evaluate N loss in brachiaria (Brachiaria decumbens after application of the herbicides glyphosate and glufosinate-ammonium, an experiment was carried out in a greenhouse as a completely randomized design, with three treatments and six replicates. Treatments were as follows: i desiccation of brachiaria-plants with glyphosate; ii desiccation of brachiaria-plants with glufosinate-ammonium; and iii control, without herbicide application. The plants were cultivated in 4 kg pots of sandy soil and fertilized with ammonium sulfate- 15N, (200 mg kg-1 in order to quantify the allocation of the fertilizer-N and its recovery in the soil-plant system. Plants treated with the herbicides had less N accumulation and less recovery of the fertilizer-N (15N relative to the control. In the soil, the greatest recovery of 15N-fertilizer occurred for treatments where N was applied, possibly due to the occurrence of other N compound losses to the soil, like root exudation and root death. The total recovery of 15N-fertilizer in the soil-plant system was higher in the control than in the treated plants showing the direct action of the herbicides on nitrogen loss, and especially by the above-ground part of the brachiaria plants.As perdas de nitrogênio no sistema solo-planta podem ser influenciadas pela aplicação de herbicidas. Com o objetivo de avaliar a perda de N do capim-Brachiaria (Brachiaria decumbens após a aplicação dos herbicidas glifosato e glufosinato de amônio, foi realizado um experimento em casa-de-vegetação em delineamento inteiramente aleatorizado (DIA, com três tratamentos e seis repetições. Os tratamentos foram os seguintes: i dessecação de plantas de braquiária com o herbicida glifosato; ii dessecação de plantas de braquiária com herbicida glufosinato de amônio e iii testemunha, sem aplicação de herbicida. As plantas foram cultivadas

  17. Composição química e digestibilidade in vitro do feno de Brachiaria decumbens Stapf. tratado com uréia Chemical composition and in vitro digestibility of Brachiaria decumbens Stapf. hay treated with urea

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    Kátia Fernanda Gobbi

    2005-06-01

    Full Text Available Avaliaram-se os efeitos da adição de uréia em níveis crescentes sobre a composição química e digestibilidade in vitro da matéria seca (DIVMS do feno de Brachiaria decumbens colhida no estádio de pós-florescimento. O feno foi tratado com seis níveis de uréia (0, 2, 4, 6, 8 e 10%, com base na matéria seca (MS. A uréia foi dissolvida em quantidade de água suficiente para elevar o teor de umidade do feno para 30%. O delineamento experimental adotado foi o inteiramente casualizado, com três repetições. O feno tratado foi armazenado em sacos plásticos (2 kg/saco vedados, por 35 dias, e, após abertura, foram coletadas amostras para as análises químicas. Verificou-se que o teor de nitrogênio total (NT aumentou linearmente em função dos níveis crescentes de uréia. Os teores de NIDN e NIDA, em relação ao nitrogênio total (NIDN/NT e NIDA/NT, tiveram redução linear em função dos níveis crescentes de uréia, demonstrando aumento nos teores de nitrogênio disponível no material amonizado. A adição de uréia promoveu redução no teor de fibra em detergente neutro (FDN, fibra em detergente ácido (FDA e celulose. Os teores de hemicelulose e lignina não foram alterados pelo tratamento com uréia. A digestibilidade in vitro da matéria seca (DIVMS foi influenciada de forma quadrática pelos níveis de uréia, estimando-se valor máximo de 68, 9% para o nível de 7, 15% de uréia. A amonização com uréia alterou a composição química e a digestibilidade do feno de Brachiaria decumbens, melhorando o valor nutritivo do material tratado.An experiment was conducted to evaluate the effects of urea treatment on the chemical-bromatologic compounds and in vitro dry matter digestibility (IVDMD of Brachiaria decumbens hay. The hay were reconstituted with water to get final forage moisture concentration of 30%, and treated with urea at 0, 2, 4, 6, 8, and 10% of the forage dry matter. A completely randomized design with three

  18. Emergência e desenvolvimento de guanxuma (Sida rhombifolia, capim-braquiária (Brachiaria decumbens e cana-de-açúcar (Saccharum spp. influenciados por subprodutos da destilação do álcool Emergence and growth of arrowleaf sida (Sida rhombifolia, brachiaria grass (Brachiaria decumbens and sugarcane (Saccharum spp. as influenced by alcohol by-products

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    A.A.P.M. Azania

    2004-09-01

    Full Text Available Este trabalho objetivou avaliar os efeitos da aplicação de óleo de fúsel, comparativamente a vinhaça e flegmaça, sobre o desenvolvimento e a composição química de plantas de guanxuma (Sida rhombifolia, capim-braquiária (Brachiaria decumbens e cana-de-açúcar (variedade RB72454, cultivadas simultaneamente em casa de vegetação. As concentrações de 12,5; 25,0; 50,0; e 100,0% (v/v de cada subproduto e a testemunha (água foram aplicadas (numa taxa equivalente a 150 m³ ha-1 no solo dos vasos (22 L, contendo uma planta de cana-de-açúcar (13 cm de altura e 100 sementes de cada planta daninha. O delineamento foi o inteiramente casualizado, com 13 tratamentos e 4 repetições, em esquema fatorial 3 x 4 (três tipos de resíduos e quatro concentrações, e uma testemunha adicional com água. O óleo de fúsel inibiu a emergência de Sida rhombifolia e Brachiaria decumbens e matou a cana-de-açúcar. A vinhaça e a flegmaça prejudicaram a emergência e o desenvolvimento de B. decumbens, bem como o de S. rhombifolia, mas não o da cana-de-açúcar.This research aimed to compare the effects of fusel oil application to those of vinasse and flegmass application on the growth and chemical composition of arrowleaf sida plants (Sida rhombifolia, brachiaria grass (Brachiaria decumbens and sugarcane (Saccharum spp., cultivated simultaneously under greenhouse conditions. Concentrations of 12.5,25.0,50.0 and 100.0 % (v/v of each by-product and the check treatment (water were applied (rate equivalent to 150 m³ ha-1 to soil on 22 L-pots, containing one sugar-cane plant (13 cm of height, and 100 seeds of each weed. The experimental design was completely randomized , with 13 treatments and 4 repetitions, in a 3x4 factorial scheme (3 by-products and 4 concentrations and an additional check treatment with water. The fusel oil inhibited Sida rhombifolia and Brachiaria decumbens emergence with no emergence being verified for sugarcane. The vinasse and

  19. EVALUACIÓN DE MÉTODOS PARA ERRADICAR HONGOS ENDÓFITOS DE SEMILLAS DE Brachiaria decumbens Stapf

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    Diana Tamayo

    2017-07-01

    Full Text Available La adaptación de plantas a ambientes extremos puede depender de la asociación con hongos endófitos de raíces. Sin embargo, las demostraciones del papel de esos endófitos en las simbiosis son limitadas si no se experimenta con plantas libres de ellos. Este estudio adaptó y evaluó un sistema de germinación masivo de semillas (SGMS para probar métodos de desinfección de semillas de Brachiaria. decumbens en estudios con hongos endófitos de raíces. Con este sistema se evaluaron en semillas métodos de desinfección externa (Soluciones de NaOCl al 5% ó Ca(ClO2 al 7,14%, o calor [60°C] en baño de agua u horno en varios tiempos, e interna (Captan™ y Benomil 50WP (0,1 mg/ml. El SGMS fue adecuado para el desarrollo de plántulas de B. decumbens ya que en cinco días se obtiene abundante material de trabajo (7 a 10 plántulas. Adicionalmente, los métodos de desinfección externa disminuyeron la actividad microbiológica superficial en semillas, comparardo con el control (agua. Aplicar NaOCl (5% resultó en mayor germinación y desarrollo de plántulas, pero no fue posible eliminar estructuras internas de hongos de las raíces, lo que sugiere una relación innata planta–endófito en pasto B. decumbens, que impide obtener plantas libres de endófitos. Algunas implicaciones experimentales son presentadas y discutidas a la luz de estos resultados.

  20. Efeitos fitotóxicos do fluoreto na morfoanatomia foliar de Brachiaria brizantha (Hochst. ex A. Rich. Stapf e Brachiaria decumbens Stapf (Poaceae Phytotoxic effects of fluoride in leaf morpho-anatomy of Brachiaria brizantha (Hochst. Ex A. Rich. Stapf and Brachiaria decumbens Stapf (Poaceae

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    Alice Pita-Barbosa

    2009-12-01

    Full Text Available Visando avaliar os efeitos do fluoreto sobre capim-braquiária, plantas de Brachiaria brizantha e B. decumbens foram submetidas a nevoeiros simulados com fluoreto (10 µg ml-1. Amostras foliares de porções aparentemente sadias foram coletadas 24 horas após a última exposição para análises microscópicas. Folhas, raízes e rizomas foram submetidos à quantificação do teor de fluoreto. As folhas apresentaram necroses pequenas e esparsas. Somente as folhas acumularam fluoreto, apresentando teores 4,4 e 5,2 vezes maiores que no tratamento controle, em B. brizantha e B. decumbens, respectivamente, não havendo diferença no potencial acumulador das duas espécies. As principais alterações micromorfológicas observadas foram lesões próximas aos tricomas, sugerindo que estes sejam as vias preferenciais de entrada do poluente nas plantas. Porções foliares, visualmente sadias, de ambas as espécies apresentaram danos microscópicos antes do surgimento de sintomas, havendo perda da turgidez das células buliformes em B. brizantha e de todos os tecidos em B. decumbens. Alterações micromorfométricas foram observadas somente em B. decumbens, indicando sua maior sensibilidade ao fluoreto, em comparação com B. brizantha. A realização de experimentos de longa duração será fundamental para elucidar o potencial bioacumulador de B. brizantha.To assess the effects of fluoride on signal grass, plants of Brachiaria brizantha and B. decumbens were submitted to simulated fluoride fog (10 µg ml-1. Leaf fragments from apparently healthy portions were colleted 24 hours after the last exposure and used for microscopic analysis. Roots, leaves and rhizomes were submitted to fluoride content quantification. The leaves presented small, sparse necroses. The accumulation of fluoride was observed on the leaves only. B. brizantha and B. decumbens presented, respectively, 4.4 and 5.2 times more fluoride than the control treatment. No difference was

  1. Efectos del antecedente cultural en las micorrizas nativas y la productividad del pasto brachiaria (Brachiaria decumbens cv. Señal Effects of the cultural antecedent on native mycorhizae and the productivity of the brachiaria pasture (Brachiaria decumbens cv. Señal

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    P.J Gonzále

    2007-03-01

    Full Text Available Se evaluó la influencia del antecedente cultural en la micorrización nativa y en el rendimiento del pasto brachiaria (Brachiaria decumbens cv. Señal; para ello se seleccionaron dos lotes de 0,5 ha, los cuales durante cinco años previos a la siembra del pasto estuvieron ocupados, en un caso por cultivos de ciclo corto (granos, viandas y hortalizas y en otro por pastos naturales permanentes (principalmente especies del complejo Bothriochloa-Dichanthium y Teramnus labialis. En cada lote se delimitaron diez parcelas de 200 m² cada una, y en mayo de 2004 se sembró la brachiaria en surcos separados a 70 cm y a chorrillo, con una dosis de 8 kg de semilla total ha-1. Después del establecimiento el pasto se cortó cada seis y ocho semanas en los períodos lluvioso y poco lluvioso, respectivamente, y en ningún momento se aplicaron fertilizantes químicos u orgánicos. En cada parcela se tomaron muestras de raíces y de suelo de la rizosfera, para determinar las estructuras micorrízicas del pasto (porcentaje de colonización, porcentaje de densidad visual y número de esporas por 100 g, así como muestras de la biomasa aérea para determinar el contenido y la extracción de macronutrientes, y el rendimiento de MS. Las parcelas que tuvieron los pastos naturales como cultivo precedente mostraron valores significativamente mayores (PThe influence of the cultural antecedent on native mycorhization and the yield of the brachiaria pasture (Brachiaria decumbens cv. Señal was evaluated; for that two 0,5 ha lots were selected, which were occupied for five years before sowing the pasture, in one case by short cycle crops (grains, tubers and vegetables and in the other by permanent natural pastures (mainly species of the Bothriochloa-Dichanthium complex and Teramnus labialis. In each lot ten plots of 200 m² each were delimited, and in May, 2004, the brachiaria was sown in rows separated by 70 cm and with drilling, with a dose of 8 kg total seed ha-1. After

  2. Efeito de Brachiaria decumbens na herbivoria e no desenvolvimento de duas leguminosas nativas de cerrado Effect of Brachiaria decumbens on herbivory and development of two cerrado native leguminosae species

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    A.C.V. Pires

    2012-12-01

    Full Text Available Este estudo avaliou o impacto da presença da gramínea exótica (Brachiaria decumbens na herbivoria e no desenvolvimento de plântulas de espécies nativas (Hymenaea stigonocarpa e Dipteryx alata de Cerrado. Para avaliar o impacto da presença da gramínea, 10 blocos em pastagem (antiga área de Cerrado na Embrapa Gado de Corte (Campo Grande-MS foram demarcados em janeiro de 2009. As gramíneas foram mantidas intactas em metade dos blocos e, na outra metade, foram removidas. Em cada tratamento, foram avaliados a herbivoria, a altura e o diâmetro na altura do solo (DAS de 25 plântulas de cada espécie ao longo do ano. O conteúdo de carbono, nitrogênio e água das folhas também foi quantificado. Plântulas de Hymenaea stigonocarpa nos tratamentos com gramínea tiveram maior taxa de crescimento em diâmetro que as plântulas no tratamento sem gramíneas. As plântulas de Dipteryx alata que estavam no tratamento sem gramíneas tiveram maiores taxas de crescimento em altura que as do tratamento com gramíneas. Houve diferença na taxa de herbivoria de D.alata entre os tratamentos. As plântulas das duas espécies que estavam no tratamento com gramínea mostraram maiores concentrações de carbono e menores de água. O conteúdo de nitrogênio foliar foi maior no tratamento com gramíneas que no sem gramíneas em D.alata; já o nitrogênio em H. stigonocarpa não variou entre os tratamentos. Esses resultados mostram que cada espécie nativa possui distintas respostas fisiológicas e suscetibilidade à herbivoria em ambientes sob competição de recursos com a gramínea exótica, B. decumbens.This study evaluated the impact of the presence of the exotic grass (Brachiaria decumbens on the herbivory and development of seedlings of native species (Hymenaea stigonocarpa and Dipteryx alata of the Cerrado. Thus, 10 pasture plots (former Cerrado at the Embrapa Gado de Corte (Campo Grande-MS were demarcated in January 2009. The grasses were kept intact

  3. Soil bulk density and biomass partitioning of Brachiaria decumbens in a silvopastoral system Densidade do solo e partição de biomassa de Brachiaria decumbens em um sistema silvopastoril

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    Domingos Sávio Campos Paciullo

    2010-10-01

    Full Text Available Shade in silvopastoral systems improves the thermal comfort of animals, but it may also affect the pasture productivity and can contribute to soil compaction in the shaded areas due to the increase in the number of animals looking for comfort. The effect of grazing at various distances from tree rows (under the tree canopy, at 6 and at 12 m away from the trees on the soil bulk density and on the aerial and root biomass of Brachiaria decumbens was evaluated in both the dry and the rainy seasons. The study was carried out on an Orthic Ferralsol in a randomized block design with two replications. Tree rows were composed of Eucalyptus grandis and Acacia mangium species, and the paddocks were submitted to a rotational stocking management, using Holstein (Bos taurus × Zebu (Bos indicus heifers. The shade intensity in the pasture decreased with an increasing distance from the tree row. Soil bulk density did not vary with the distance from the tree row, but varied seasonally, being greater in the rainy season (1.47 g cm-3 than in the dry season (1.28 g cm-3. Green forage and root mass, expressed as dry matter, were lower under the tree canopy and were greater in the rainy season. There were decreases of 22.3 and 41.4% in the aerial and root biomasses, respectively, in the tree rows. The greatest shoot/root ratio for B. decumbens under moderate and intensive shading indicates a modification in the forage biomass allocation pattern that favours the aerial development in detriment of the root system.O sombreamento em sistemas silvipastoris concorre para o conforto térmico dos animais; no entanto pode afetar a produção do pasto e contribuir para a compactação do solo, pelo aumento da concentração de animais nas áreas sombreadas. Avaliou-se o efeito da distância do renque de árvores (sob a copa das árvores, 6 e 12 m de distancia das árvores na densidade do solo e na biomassa aérea e de raízes de Brachiaria decumbens, nas épocas seca e chuvosa

  4. Características Agronômicas, Massa de Forragem e Valor Nutritivo de Brachiaria decumbens em Sistema Silvipastoril Agronomics Characteristics, Forage Mass and Nutritional Value of Brachiaria decumbens in a Silvopastoral System

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    Carlos Renato Tavares Castro

    2010-02-01

    Full Text Available

    Avaliaram-se os efeitos de três porcentagens de sombreamento (0, 29% e 45%, proporcionado pelas leguminosas arbóreas Acacia angustissima, A. mangium, A. auriculiformis, Albizia lebbek e Gliricidia sepium, sobre características agronômicas, e o valor nutritivo do pasto de Brachiaria decumbens, durante o inverno, a primavera e o verão. Foi adotado o delineamento experimental de blocos casualizados, com três repetições. O sombreamento influenciou positivamente a massa de forragem, na primavera e no verão. No inverno, a maior massa de forragem foi obtida sob sol pleno. Os teores de proteína bruta aumentaram com o sombreamento, na primavera, mas não se modificaram em função das porcentagens de sombra, no inverno e no verão. Pelo produto da massa de forragem e o teor de proteína bruta, obtiveram-se as quantidades de proteína bruta por área, que foram maiores sob sombreamento mais intenso, na primavera e no verão. Os teores de fibra em detergente neutro e a digestibilidade in vitro da matéria seca não apresentaram tendência consistente com as porcentagens de sombreamento, em função da forte interação deste tratamento com a estação do ano.

     

    doi: 10.4336/2009.pfb.60.19

    The agronomic traits and nutritive value of Brachiaria decumbens pasture were evaluated under three shade percentages (0.29% and 45%, provided by leguminous trees (Acacia angustissima, A. mangium, A. auriculiformis, Albizia lebbek e Gliricidia sepium, during winter, spring and summer seasons. The experimental design was randomized blocks, with three replications. The forage mass was positively influenced by shading, in spring and summer seasons. In winter, the higher forage mass was observed in full sunlight condition. The values of crude protein increased in spring with shading, but did not vary with shade percentage in winter and summer seasons. The crude protein quantity per area, obtained by product between forage mass and crude protein

  5. CALCIUM SOURCE EFFECT ON APPARENT DIGESTIBILITY OF GRASS HAY Brachiaria decumbens Staph cv. Basiliski EFEITO DA FONTE DE CÁLCIO (calcário vs Lithothamnium calcareum NA DIGESTIBILIDADE APARENTE DE CAPIM Brachiaria decumbens Staph cv. Basiliski

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    Deborah Gonçalves Rodrigues

    2007-09-01

    Full Text Available

    An experiment was developed to determine the effect of addition of the marine alga Lithothamnium calcareum in the apparent digestibility of a low quality forage. Twelve adult lambs were kept in metabolical individual cages using a randomly design with three replications and four treatments as follows: I - Brachiaria decumbens grass hay, processed after the seed harvest; II - Hay plus 1000 ppm of calcium from CaCO3 (p.a.; III - Hay plus 1000 ppm of calcium from mineral supplement of alga; IV - Hay plus 2000 ppm of calcium from mineral supplement of alga. The mineral supplement of alga increased the digestibility of crude protein in 7,5% with dosage 1000 ppm and in 12% with dosage of 2000 ppm, when compared with control treatment, but such changes were not significant (P < 0,05. No differences were observed for dry matter and crude fiber.

    Um experimento foi conduzido para determinar o efeito da adição de alga marinha Lithothamnium calcareum na digestibilidade aparente de uma forragem de baixa qualidade. Doze carneiros adultos foram distribuídos em gaiolas metabólicas, inteiramente casualizadas com três repetições. Os tratamentos utilizados foram: I - Feno de capim Brachiaria decumbens, confeccionado após a colheita das sementes; II - Feno mais 1000 ppm de cálcio proveniente do carbonato de cálcio (p.a.; III - Feno mais 1000 ppm de cálcio proveniente do suplemento mineral de alga (L.C. - 400; IV - Feno mais 2000 ppm de cálcio proveniente do suplemento mineral de alga (L.C. - 400. O suplemento mineral aumentou a digestibilidade da proteína bruta em 7,5% na dosagem de 1000 ppm e em l2% na dosagem de 2000 ppm, quando comparados ao tratamento controle, mas tais mudanças não foram significativas (P < 0,05. Não alterou a digestibilidade da matéria seca e fibra bruta.

  6. Características estruturais e índice de tombamento de Brachiaria decumbens cv. Basilisk em pastagens diferidas Structural characteristics and falling index of Brachiaria decumbens cv. Basilisk on deferred pastures

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    Manoel Eduardo Rozalino Santos

    2009-04-01

    Full Text Available Objetivou-se avaliar o efeito dos períodos de diferimento e de pastejo sobre a densidade populacional de perfilhos, a massa dos componentes morfológicos da forragem e o índice de tombamento em pastagens de Brachiaria decumbens cv. Basilisk. Dois ensaios foram conduzidos: o primeiro denominado ano 1 e, o segundo, ano 2. Adotou-se o esquema de parcelas subdivididas, segundo o delineamento em blocos casualizados, com duas repetições para cada combinação dos períodos de diferimento da pastagem com os períodos de pastejo. No ano 1, os períodos de diferimento foram 103, 121, 146 e 163 dias; e no ano 2, foram 73, 103, 131 e 163 dias. Os períodos de pastejo foram 1, 29, 57 e 85 dias. O aumento do período de diferimento elevou a densidade populacional de perfilhos reprodutivos (ano 2: de 37 para 304 perfilhos/m² e reduziu a de perfilhos vegetativos (ano 1: de 1.253 para 889 perfilhos/m²; ano 2: de 1.235 para 627 perfilhos/m². Durante o período de pastejo, ocorreu diminuição no número de perfilhos vegetativo (ano 1: de 988 para 868 perfilhos/m² e reprodutivo (ano 1: de 216 para 0 perfilhos/m²; ano 2: de 203 para 0 perfilhos/m² e aumento no número de perfilhos mortos (ano 1: 463 para 1.088 perfilhos/m²; ano 2: de 341 para 1.010 perfilhos/m². Pastagens sob maiores períodos de diferimento e de pastejo apresentaram maior massa de colmo morto (6.093 e 3.819 kg/ha de MS nos anos 1 e 2, respectivamente e menor massa de lâmina foliar verde (341 e 177 kg/ha de MS nos anos 1 e 2, respectivamente. Pastos de Brachiaria decumbens cv. Basilisk, submetidos a longos períodos de diferimento e de pastejo possuem características estruturais desfavoráveis à produção animal.This worked aimed to evaluate the effects of deferring and grazing periods on the tiller population density, morphological component mass of forage and falling index on Brachiaria decumbens cv. Basilisk pastures. Two assays were carried out: first year and second year

  7. SIMBIOSIS MICORRIZICA ARBUSCULAR Y ACUMULACIÓN DE ALUMINIO EN Brachiaria decumbens Y Manihot esculenta SIMBIOSE MICORRIZICA ARBUSCULAR E ACUMULAÇÃO DE ALUMÍNIO EM Brachiaria decumbens E Manihot esculenta ARBUSCULAR MYCORRHIZAL SYMBIOSIS AND ACUMULATION OF ALUMINUM Brachiaria decumbens AND Manihot esculenta

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    BEATRIZ ELENA GUERRA S.

    2012-12-01

    Full Text Available Suelos dedicados al monocultivo de Elaeis guineensis Jacq en Puerto Wilches-Santander-Colombia, presentan baja fertilidad, altas saturaciones de aluminio y baja densidad de esporas de hongos micorrizicos. Se evaluó el comportamiento de la simbiosis micorrizica utilizando suelos nativos con micorrizas (MA+ y sin micorrizas (MA-, en Brachiaria decumbens y Manihot esculenta, quienes poseen alta micotrofia y capacidad de retención del ión aluminio. Se consideraron las variables densidad de esporas, porcentaje de colonización micorrizica, biomasa seca y longitud radicular, concentración de aluminio foliar y radicular. Se realizó una (ANOVA de dos vías con un modelo lineal general. Se observaron porcentajes de colonización micorrizica superiores al 70% en B. decumbens en suelos con concentraciones de 0,6 y 1,4 meq/100 g de Aluminio. M. esculenta presento 50 % de simbiosis micorrizica, en todos los tipos de suelo. Se incrementaron las esporas nativas de palma aceitera hasta un 200% en las dos plantas huespéd. Las concentraciones de aluminio a nivel radicular fueron mayores en plantas micorrizadas, mientras que a nivel foliar los valores fueron más bajos.Solos dedicados à monocultura de Elaeis guineensis Jacq em Puerto Wilches-Santander apresentam baixa fertilidade, alta saturação de alumínio e baixa densidade de esporos de fungos micorrízicos. Avaliaram-se o comportamento da simbiose micorrízica usando solos nativos com fungos micorrízicos (MA+ e sem fungos micorrízicos (MA-, na Brachiaria decumbens e Manihot esculenta, plantas com alto grau de micotrofia e capacidade de retenção de íons de alumínio. Considerou-se as variáveis: densidade de esporos, porcentagem de colonização micorrízica, biomassa seca, longo da raiz e concentração de alumínio nas folhas e raízes. Realizou-se uma (ANOVA de duas vias com o modelo linear geral. Observou-se porcentagens de colonização micorrízica acima de 70% na B. decumbens em solos com

  8. Germinação de sementes de Sida rhombifolia e Brachiaria decumbens influenciada por vinhaça, flegmaça e óleo de fúsel Germination of Sida rhombifolia and Brachiaria decumbens seeds influenced by vinasse, flegmass and fusel oil

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    A.A.P.M. Azania

    2003-12-01

    Full Text Available Este trabalho objetivou avaliar, em condições de laboratório, a germinação de sementes de Sida rhombifolia e Brachiaria decumbens submetidas à aplicação de vinhaça, flegmaça e óleo de fúsel. Esses subprodutos, nas concentrações de 12,5; 25,0; 50,0; e 100,0% (v/v, e as testemunhas (água com pH e osmolalidade corrigidos, em função da caracterização realizada nos subprodutos e em suas diluições foram aplicados diretamente em 100 sementes acondicionadas em caixas de plástico, utilizando papel como substrato. O delineamento experimental foi o inteiramente casualizado, e as médias obtidas foram submetidas ao teste de Tukey. As sementes de Sida rhombifolia submetidas ao óleo de fúsel não germinaram e apresentaram redução na viabilidade, principalmente nas maiores concentrações de aplicação. As sementes de Brachiaria decumbens submetidas à maior concentração de flegmaça apresentaram tendência de redução da viabilidade e do índice de velocidade de germinação (IVG. Na presença do óleo de fúsel as sementes de Brachiaria decumbens não germinaram e apresentaram-se totalmente inviáveis.This research aimed to evaluate the effects of vinasse, flegmass and fusel oil (distillery by-products on the germination of Sida rhombifolia and Brachiaria decumbens seeds, under laboratory conditions. By-product concentrations (12.5; 25.0; 50.0 and 100.0% v/v and the controls (water with pH and osmolality amended according to by-product composition and levels were applied directly on plastic boxes filled with 100 seeds of the same species. The experiment was arranged in a randomized complete design and the data were submitted to the Tukey test. Sida rhombifolia seeds submitted to fusel oil did not germinate, reducing seed viability mainly at the largest application rates. Brachiaria decumbens seeds submitted to the highest flegmass rate tended to reduce seed viability and germination speed index (GSI. Brachiaria decumbens seeds

  9. Study on mutagenesis of Signal grass (Brachiaria decumbens) by gamma irradiation

    International Nuclear Information System (INIS)

    Abdul Rahim Harun; Shuhami Shamsuddin; Ghazali Hussin

    2000-01-01

    Before starting experiments on induced mutation breeding of crops it is essential to carry out radiosensitivity test when determining the optimum doses of every plant genotype. Factors such as moisture content and oxsigen availability could influence mutagenesis process through ionizing radiation. Many methodologies could be used for determining the effect of radiation on seed of plants such as the 'Sandwich blotter technique' and 'Sand bed technique'. Different species have different sensitivity to mutagenic agents. Even varieties of the same species show variations in sensitivity to irradiation. Brachiaria clecumbens was found to be less sensitive to gamma radiation. At a dose of 800 Gy, the percentage reduction in growth was around 40%. Early result has shown that the optimum doses for mutagenesis was between 700 to 900 Gy

  10. INFLUÊNCIA DOS SISTEMAS DE MANEJO DO SOLO SOBRE OS COMPONENTES DE PRODUÇÃO DO MILHO E Brachiaria decumbens

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    Rodrigo Gomes Pereira

    2009-01-01

    Full Text Available This work had the objective to assess the effect of different systems of soil management on the components of corn and Brachiaria decumbens production in the conditions of the coastal plateau of the State of Alagoas. The experiment was carried out in the Center of Agrarian Sciences of the Federal University of Alagoas in the year of 2006, in a Yellow Latosol (Oxisols Cohesive dystrophic soil. The treatments used were: usual preparation system (SPC; minimum cultivation (SCM; direct plantation (SPD and farming-cattle integration (ILP, this one joined with B. decumbens. The hybrid of maize BRS 3003 was used whose variable had been: number of plants ha-1 (PP, length of spikes (CE, number of row grains on spikes-1 (NF, number of spike (NE, mass of 100 grains (M100 and grain yield (PG; and fresh weight (MN and dry weight (MS of the B. decumbens. The results showed that the soil management systems influenced the PP, NE and PG, but not the variables CE, NF and M100. The treatments ILP and the PD were the most promising management systems. In system ILP, the accumulation of MN and MS did not have influence in the production of corn grains, representing an interesting food source for farm animals.

  11. EDTA-induced phytoextraction of lead and barium by brachiaria (B. decumbens cv. Basilisk in soil contaminated by oil exploration drilling waste

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    André Fernão Martins de Andrade

    2014-08-01

    Full Text Available The phytoextraction of heavy metals using chelating agents has been widely studied for the remediation of contaminated soils. To evaluate the efficiency of EDTA-induced phytoextraction of Ba and Pb using Brachiaria decumbens for the remediation of soil contaminated by oil well drilling and exploration waste, an experiment was conducted by applying a single dose (6 mmol EDTA kg-1 soil and split doses of EDTA (three applications of 2 mmol EDTA kg-1 soil. The samples were subjected to sequential extractions using the method proposed by Ure et al. (1993 as modified by Rauret et al. (1999.The application of EDTA did not influence the distribution of Ba in various chemical fractions of the soil. The dry matter production did not differ significantly between the treatments and the control, thereby demonstrating the tolerance of plants to the experimental conditions. The absorption of Pb by plants was influenced by the application of EDTA. The application of a single dose of EDTA influenced the absorption of Pb and its translocation to the aerial plant parts. The application of split doses favoured higher accumulation of Pb in roots. Because of its tolerance to heavy metals and EDTA, B. decumbens has the potential to be used in phytostabilisation.

  12. Efecto del potasio sobre la producción y calidad de forraje de Brachiaria decumbens Stapf en el piedemonte de los Llanos Orientales de Colombia

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    Álvaro Rincón Castillo

    2011-07-01

    Full Text Available En el Centro de Investigaciones La Libertad, de la Corporación Colombiana de Investigación Agropecuaria (Corpoica, localizado en Villavicencio, Meta (Colombia, en un Oxisol de terraza media con un contenido de 0.08 cmol%kg de potasio (K, en un diseño de bloques completos al azar en parcelas divididas con cuatro replicaciones, se evaluó el efecto de cuatro niveles de K (30 kg%ha, 60 kg%ha, 90 kg%ha y 120 kg%ha en la producción de forraje de Brachiaria decumbens. Como parcela principal se evaluaron la aplicación de fertilización básica y sin fertilización básica. La primera consistió en (kg%ha de 100, 60, 30, 3, 01 y 0.5 de P2O5, N, S, Zn, Cu, y B, respectivamente. No se encontraron diferencias significativas en la producción de forraje entre los niveles de K aplicados. En las condiciones del ensayo B. decumbens responde bien a 30 kg%ha de K. No obstante, la fertilización básica aplicada junto con el K contribuyó a mejorar la producción de forraje hasta los 12 meses después de su aplicación. La concentración de K en el suelo, en los tratamientos evaluados, fue > 0.10 cmol%kg, un nivel adecuado para el desarrollo de pastos poco exigentes como B. decumbens.

  13. INOCULACIÓN DE Brachiaria decumbens CON HONGOS FORMADORES DE MICORRIZA ARBUSCULAR NATIVOS DEL TRÓPICO HÚMEDO ECUATORIANO

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    Oscar Prieto Benavides

    2012-01-01

    Full Text Available Se realizó un estudio bajo condiciones semicontroladas de invernadero, para determinar el efecto de hongos formadores de micorriza arbuscular (HMA nativos de sistema agroforestales tradicionales con Theobroma cacao L. (cacao tipo nacional (SAF-C en el Trópico húmedo ecuatoriano, sobre pasto Brachiaria decumbens. El experimento se realizó entre los meses junio y diciembre del año 2009, estuvo constituido por cinco tratamientos, que consistían en la inoculación de HMA originarios de SAF-C, distribuidos en un diseño completo al azar (DCA: T1: Glomus spp., T2: Scutellospora spp., T3: Glomus spp.+ Scutellospora spp., T4: Acaulospora spp. + Gigaspora spp., T5: Control (H2O destilada estéril, en plántulas de B. decumbens sembradas en macetas plásticas de 1,000 cm3, conteniendo como sustrato una mezcla de suelo pobre en nutrientes + tamo de arroz, estériles, en proporción 3:1. El inóculo estuvo constituido de 30 esporas de HMA por tratamiento. Se analizaron las variables: a número de esporas de HMA por 100 g de suelo húmedo (gsh-1, b porcentaje de colonización micorrícica visual y categoría de pelos radicales, c altura de plantas, d peso húmedo y seco del sistema foliar y radical, e largo total de raíz (RL, y f densidad radical (RLv, a 78 y 103 días después de las inoculaciones. Las plantas inoculadas con Glomus spp., o en combinación con Scutellospora spp. mostraron mejores respuestas en las variables evaluadas. Los resultados demostraron la eficiencia y potencial de los HMA procedentes de SAF-C, sobre plantas de B. decumbens.

  14. Desempenho produtivo, características de carcaça e avaliação econômica de bovinos cruzados, castrados e não-castrados, terminados em pastagens de Brachiaria decumbens Productive performance, carcass characteristics and economic evaluation of castrated and non-castrated crossbred bovines finished in Brachiaria decumbens pastures

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    L.C.V. Ítavo

    2008-10-01

    Full Text Available Avaliou-se o efeito da castração sobre o desempenho produtivo e sobre as características de carcaça e realizou-se a avaliação econômica de bovinos terminados em pastagens de Brachiaria decumbens. Foram utilizados oito novilhos Canchim-Nelore com 14 meses de idade, sendo quatro animais castrados e quatro não-castrados, com média de peso corporal de 273,2kg. O delineamento foi inteiramente ao acaso com quatro repetições por tratamento. Os animais receberam, diariamente, 0,7% do PC de suplemento proteíco-energético e foram abatidos aos 26 meses de idade. O peso de abate e o ganho médio diário (GMD diferiram entre castrados e não-castrados, com médias de 441,0 e 482,2kg e 0,6 e 0,7kg/dia, respectivamente. Não houve efeito da castração sobre as características avaliadas, com exceção do peso de abate, do peso da carcaça quente, 252,3 versus 229,9kg, da cor da carne, 3,25 versus 4,50 pontos e da espessura da gordura subcutânea, 0,6 versus 1,4mm, respectivamente, para não-castrados e castrados. A lucratividade por animal e por hectare foi de 14,5 e 15,8% para não-castrados e 4,5 e 5,8% para castrados, respectivamente. Sugere-se a utilização de bovinos não-castrados suplementados em pastagens de Brachiaria decumbens.The effect of the castration on the productive performance and carcass characteristics was studied, as well as, the economic evaluation of finished bovines raised on Brachiaria decumbens pastures. Eight Canchim-Nellore steers aging 14-months-old were used, being four castrated and four non-castrated, averaging 273.2kg body weight. It was used a completely randomized design with four repetitions per treatment. The animals received 0.7% of their body weight of proteic-energetic supplement and were slaughtered at 26 months of age. The weight at slaughtering and the average daily weight gain differed between castrated and non-castrated, averaging 441.0 and 482.2kg, and 0.6 and 0.7kg/day, respectively. No effects of

  15. Comportamiento ecofisiológico de Brachiaria decumbens en monocultivo y en asociación con Leucaena leucocephala Ecophysiological performance of Brachiaria decumbens in monocrop and in association with Leucaena leucocephala

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    A Rodríguez-Petit

    2008-09-01

    Full Text Available Con el objeto de estudiar las relaciones ecofisiológicas que determinan el crecimiento de B. decumbens en monocultivo (MO y asociada a L. leucocephala (AS, se realizaron evaluaciones de radiación fotosintéticamente activa (RFA, asimilación (A, conductancia estomática (Gs, transpiración (E, humedad relativa (HR, po­tencial hídrico de la hoja (Øh, diferencial de presión vapor (DPV e índice de área foliar (IAF en ambas condiciones (AS y MO, en una zona de bosque húmedo tropical; estas evaluaciones se hicieron a los 5, 10 y 22 días después del pastoreo en ambas condiciones. Los valores más positivos de Øh se encontraron en AS, al igual que los valores más bajos de RFA, con diferencias significativas (PIn order to study the ecophysiological relations that affect the growth of B. decumbens in monocrop (MO and associated with L. leucocephala (AS, evaluations of photosynthetic active radiation (PAR, assimilation (A stomatic conductance (Gs, transpiration (E, relative humidity (RH, water potential (Øh, differential of steam pressure (DSP and leaf area index (LAI were made in a tropical humid forest zone. The evaluations were made 5, 10 and 22 days after grazing under both conditions (MO and AS. The most positive values of Øh (P<0,05 were found in AS, as well as the lowest values of PAR (P<0,05 in all the evaluated dates. RH and DSP did not show differences (P 0,05. The gas exchange parameters (E, Gs and A showed significantly higher values in MO (P<0,05 in all dates. LAI was higher in MO after 10 and 22 days of evaluation. Due to the limitation of the photosynthetic capacity exerted by the light decrease on the grass, that PAR is concluded to be the most important factor that determine growth and development of B. decumbens in AS.

  16. Balanço hídrico em Neossolo regolítico cultivado com braquiária (Brachiaria Decumbens Stapf

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    Renan Almeida Brito da Silva

    2014-02-01

    Full Text Available Um dos principais fatores de produção para as culturas é a disponibilidade de água no solo, de forma que a quantificação das entradas e saídas dessa água, por meio do método do balanço hídrico, pode ser um instrumento valioso para melhorar o manejo dado a ela. Desse modo, este trabalho teve como objetivo analisar os componentes do balanço hídrico (variação do armazenamento de água no solo, drenagem, ascensão capilar e evapotranspiração e o perfil do sistema radicular em Brachiaria decumbens, em nove meses do ano de 2011 (março a novembro. Também foi avaliada a razão entre evapotranspiração (ET e evapotranspiração de referência (ETo. Esta pesquisa foi realizada na fazenda Riacho do Papagaio, em São João, na mesorregião do Agreste do Estado de Pernambuco, onde foram instalados sensores automatizados para medição da umidade volumétrica do solo nas profundidades de 0,10; 0,20; 0,30; e 0,40 m. A precipitação pluvial foi monitorada por meio de um pluviógrafo automatizado instalado numa torre no centro da área. Para a determinação da drenagem e da ascensão capilar, foram realizados ensaios de infiltração para obtenção da condutividade hidráulica do solo, além da determinação da curva de retenção, em laboratório. A ET foi obtida como termo residual da equação do balanço hídrico e a ETo, pelo método de Penman-Monteith. O volume de controle utilizado para o balanço hídrico teve como limite superior a superfície do solo e como limite inferior a profundidade de 0,30 m. Também foi analisado o perfil do sistema radicular da braquiária, mensalmente. Observou-se que os períodos com elevadas pluviosidades resultaram num maior armazenamento de água no solo, em maiores valores de drenagem e de evapotranspiração. O fluxo de água no limite inferior (z = 0,30 m do solo ocorreu somente no sentido descendente, sendo perdidos 103,14 mm de água por drenagem, o que representa 24,12 % de toda a

  17. Disponibilidade, composição bromatológica e consumo de matéria seca em pastagem consorciada de Brachiaria decumbens com Stylosanthes guianensis Herbage availability, chemical composition and dry matter intake in mixed pasture of Brachiaria decumbens with Stylosanthes guianensis

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    Luiz Januário Magalhães Aroeira

    2005-04-01

    Full Text Available O objetivo deste trabalho foi avaliar a disponibilidade de forragem, a composição bromatológica, o consumo de matéria seca e a proporção de gramínea e leguminosa na dieta de vacas mestiças Holandês x Zebu, em pastagem consorciada de Brachiaria decumbens cv. Basilisk, Stylosanthes guianensis var. vulgaris cv. Mineirão e leguminosas arbóreas. Para estimativa da produção fecal, foram usados 10 g vaca-1 dia-1 de óxido crômico, durante dez dias. Amostras de extrusa foram usadas para determinação da composição bromatológica e digestibilidade in vitro da matéria seca. A disponibilidade de matéria seca de forragem de B. decumbens variou com as condições climáticas, enquanto a de S. guianensis decresceu linearmente ao longo do período experimental. O consumo de matéria seca foi maior em maio de 2001 (1,9% do peso do animal vivo e não diferiu entre os demais meses (1,5% do peso do animal vivo. Os baixos índices de consumo de matéria seca refletiram altos teores de fibra em detergente neutro (70,2% a 79,4% e baixos coeficientes de digestibilidade in vitro de matéria seca (42,1% a 48,0% da forragem. O consumo de leguminosa variou entre 8,7% e 24,1% do total ingerido. O consumo de matéria seca esteve diretamente relacionado à porcentagem de leguminosa na pastagem, o que evidencia o potencial de uso de pastagens consorciadas para vacas leiteiras.The objective of this work was to evaluate the herbage availability, nutritive value, dry matter intake and grass and legume percentage in diet of crossbred Holstein-Zebu cows, in pasture with Brachiaria decumbens cv. Basilisk, Stylosanthes guianensis var. vulgaris cv. Mineirão and tree legumes. To estimate the fecal output, it was used 10 g cow-1 day-1 of chromium oxide during ten consecutive days. Extrusa samples were used to determine the chemical composition and in vitro dry matter digestibility. B. decumbens availability varied with climatic conditions, while S. guianensis

  18. Variação sazonal da bioquímica clínica de vacas aneloradas sob pastejo contínuo de Brachiaria decumbens Seasonal changes of clinical biochemistry of graded Nelore cows on continuous grazing of Brachiaria decumbens

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    M.G. Morais

    2000-04-01

    Full Text Available Em um esquema de parcela subdividida que incluía dois tratamentos (A= solo arenoso e B= solo argiloso e 10 subtratamentos (10 épocas de amostragem a bioquímica clínica de 20 vacas de corte, sob pastejo contínuo de B. decumbens, foi acompanhada durante 13 meses. Os constituintes sangüíneos estudados foram: glicose (GLI, hemoglobina (HB, bilirrubina (BIL, creatinina (CREA, albumina (ALB, aspartatoaminotransferase (AST, fosfatase alcalina (FAS e creatinoquinase (CK. Foram obtidos valores médios de 98,0 e 110,2 mg/dl para GLI, 13,27 e13,38g/l para HB, 0,718 e 0,661mg/dl para BIL, 1,89 e 1,73mg/dl para CREA e 3,56 e 3,39g/dl para ALB nos tratamentos A e B, respectivamente. Vacas aneloradas apresentaram um perfil bioquímico clínico de animais aparentemente sadios, isto é, ausência de anemia, icterícia e disfunção renal. Não foi possível diagnosticar alterações hepáticas mas ocorreram lesões musculares (CK em algumas épocas, sem afetar clinicamente os animais. GLI, ALB, AST e FAS apresentaram mudança sazonal com níveis mais altos na primavera-verão e mais baixos no período de seca, no outono-inverno.A split plot design was carried out in order to study the clinical biochemistry of 20 graded Nelore cows on continuous grazing of Brachiaria decumbens on sandy (treatment A or on clay soil (treatment B. The mean values for the blood components were glucose, 98.0 and 110.2 mg/dl; hemoglobin, 13.27 and 13.38 g/l; bilirubin, 0.718 and 0.661 mg/dl; and creatinine, 1.89 and 1.73 mg/dl, on treatments A and B, respectively. Albumin, aspartate aminotransferase, alkaline phosphatase, and creatine kinase were also evaluated. The cows showed a metabolic profile similar to healthy-like animals, i.e., without anemia, jaudice, and renal disorder. It was not possible to detect abnormal liver function because of the need of inclusion of one specific liver enzyme in the clinical analysis. Muscular lesions were occasionally observed, even though the

  19. Avaliação de pastagem diferida de Brachiaria decumbens Stapf. 2. Disponibilidade de forragem e desempenho animal durante a seca Evaluation of a signalgrass (Brachiaria decumbens Stapf postponed pasture. 2. Availability of herbage and animal performance, during the dry season

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    Eduardo Destéfani Guimarães Santos

    2004-02-01

    Full Text Available Verificaram-se as disponibilidades de forragem total, forragem verde e morta e dos componentes folha verde, caule verde, folha seca e caule seco em pastagem diferida de Brachiaria decumbens. A pastagem foi vedada à entrada dos animais de dezembro de 1996 a junho de 1997 e avaliada, sob pastejo contínuo, durante a estação seca, nos meses de julho a outubro de 1997. Também foram estudadas correlações entre características do relvado e ganho de peso de tourinhos Limousin-Nelore com 19 meses e 374 kg de peso. O diferimento da pastagem de Brachiaria decumbens proporcionou disponibilidade média de forragem (DMST de 7.568, forragem verde (DMSV de 3.834 e morta (DMSM de 3.734 kg de matéria seca (MS/ha em julho, antes do período de pastejo. A utilização contínua da pastagem diferida durante o período seco, com lotação animal de 0,75 UA/ha, não afetou a DMST, média de 7.902, e DMSM, média de 4.637 kg/ha, mas afetou a DMSV e a disponibilidade de folhas verdes (DMSFV. A DMSV e a DMSFV apresentaram taxas crescentes em julho e outubro e diminuíram a taxas crescentes em agosto e setembro. No final de setembro, as pastagens apresentaram a menor DMSV, 2.540 kg/ha. A DMSFV e a proporção de folhas verdes no relvado foram maiores no início de agosto, respectivamente, 1.517 kg/ha e 18,5%, e menores no final de setembro, 480 kg/ha e 5,7%, respectivamente. O diferimento da pastagem permitiu a manutenção dos animais e apenas pequeno ganho de peso durante a seca, média de 104 g/dia. Em setembro, os animais nas pastagens perderam peso. O ganho de peso vivo médio diário correlacionou-se linear e negativamente com DMSM e linear e positivamente com as relações [DMSV/DMSM] e [DMSFV/(DMSM + DMSCV], em que DMSCV é a disponibilidade de matéria seca de caule verde. Não foram verificadas correlações entre ganho de peso e as variáveis DMSV, DMSFV, pressão de pastejo e oferta diária de forragem.The availability of herbage, green herbage, dead

  20. Avaliação lectino-histoquímica de fígado e rim de ovinos com fotossensibilização causada por Brachiaria decumbens

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    Samay Z.R. Costa

    2013-08-01

    Full Text Available Embora sejam as forrageiras mais importantes para a pecuária de corte (bovinocultura de corte no Brasil, em certas épocas ou condições, Brachiaria spp. podem ser tóxicas e causar surtos de fotossensibilização hepatógena que determinam significativas perdas econômicas. Animais que se alimentam em pastos de Brachiaria spp. comumente apresentam macrófagos espumosos isolados ou agrupados, além de cristais no interior de ductos biliares. Saponinas esteroidais têm sido identificadas nestes cristais e são responsabilizadas por lesar o fígado levando ao acúmulo de filoeritrina. Por vezes, imagens negativas desses cristais podem estar presentes no citoplasma de macrófagos espumosos. A patogênese de formação e o tipo de material armazenado nas células espumosas ainda são desconhecidos. A técnica de lectino-histoquímica visa auxiliar na detecção desses macrófagos e, consequentemente, no diagnóstico, além de identificar quais os resíduos de açúcares específicos que estão presentes no citoplasma das células espumosas. Assim, este trabalho teve por objetivo identificar quais lectinas são mais indicadas na detecção de saponinas esteroidais no fígado e rim de ovinos com fotossensibilização causada por Brachiaria decumbens. Fragmentos de fígado e rim de quinze ovinos, de ambos os sexos e idade variável, oriundos de Conceição do Mato Dentro, Minas Gerais, e um ovino mantido em pastagem livre de Brachiaria spp. foram avaliados pela técnica de lectino-histoquímica. Quatorze lectinas foram utilizadas (Con-A, DBA, SBA, PNA, SJA, RCA-I, UEA-I, WGA, SWGA, GSL, PSA, PHA-L, PHA-E e LCA. Verificou-se que, no fígado de ovinos com fotossensibilização provocada pela ingestão de Brachiaria decumbens, a lectina PNA apresentou especificidade e acentuada reatividade aos macrófagos espumosos, bem como especificidade e leve reatividade aos hepatócitos; a lectina WGA teve especificidade e moderada reatividade aos macr

  1. 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

  2. Estoque de serapilheira e fertilidade do solo em pastagem degradada de Brachiaria decumbens após implantação de leguminosas arbustivas e arbóreas forrageiras

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    André Barbosa Silva

    2013-04-01

    Full Text Available As pastagens formam a base da pecuária brasileira; essas sofrem degradação em larga escala por deficiência de nitrogênio (N. O consórcio com leguminosas, além de fixar N, pode apresentar outros efeitos na fertilidade do solo como acidificação ou retirada de nutrientes de camadas mais profundas para as mais superficiais. Este trabalho objetivou avaliar o estoque de serapilheira e a fertilidade do solo em pastagens degradadas de braquiária (Brachiaria decumbens, após implantar leguminosas arbustivas e arbóreas forrageiras. Para isso, uma amostragem foi realizada em março de 2010 em um experimento no campo, introduzindo pastagem degradada de Brachiaria decumbens, em julho de 2008, com sabiá (Mimosa caesalpiniifolia, leucena (Leucaena leucocephala, mororó (Bauhinia cheilantha e gliricídia (Gliricidia sepium, além de braquiária adubada e não adubada com N. As amostras de solo e serapilheira foram coletadas aos 0-10, 10-20 e 20-40 cm de profundidade, em três transectos, alternando pontos cobertos por gramíneas e leguminosas, totalizando sete amostras compostas por parcela para determinar pH, P, K, Ca, Mg e Al no solo, enquanto SB, t e m foram calculados. A serapilheira foi separada visualmente em leguminosas, gramíneas e materiais não identificados, em que foram utilizados para quantificação de matéria seca, matéria orgânica, N, P, C, fibra detergente ácido e lignina. A introdução das leguminosas aumentou os teores de N total na serapilheira e reduziu as relações C:N, com destaque para gliricídia e sabiá; entretanto, essa última apresentou elevados teores de lignina. Houve efeito significativo da cobertura por leguminosas, sem diferenças entre essas, para pH e K, na profundidade de 0-10 cm, e para Al e m, aos 10-20 cm de profundidade.

  3. Tratamento do feno de braquiária pelo fungo Pleurotus ostreatus Pretreatment effects on fiber degradation of brachiaria hay by Pleurotus ostreatus fungus

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    Patrick Schmidt

    2003-12-01

    Full Text Available A inoculação de forragens com fungos lignocelulolíticos é uma opção para melhorar a qualidade destas sem adição de produtos químicos. O tratamento do substrato influencia a ação do fungo e a qualidade final do produto. Neste experimento, aplicaram-se quatro tratamentos (compostagem do feno inteiro, compostagem do feno picado, hidratação do feno em água fria e hidratação do feno em água quente a um feno de Brachiaria decumbens. Aos tratamentos seguiu-se inoculação com o fungo Pleurotus ostreatus e incubação por 35 dias, sob temperatura controlada. Usou-se o delineamento inteiramente casualizado, com quatro repetições e medidas repetidas. Amostras foram colhidas semanalmente para acompanhar a degradação do substrato, mediante a análise química do feno. Observou-se aumento linear, com o decorrer do tempo, no teor de proteína bruta (PB e na proporção de lignina na parede celular (LIG-FDN, e decréscimo linear nos valores de fibra em detergente neutro (FDN, celulose e hemicelulose. Não se observou efeito de tratamento no teor de FDA. Os tratamentos com compostagem apresentaram maiores valores de PB, lignina e LIG-FDN e menores de FDN e hemicelulose. Não se observou diferença entre os tratamentos com hidratação. O tratamento do feno de braquiária com o fungo propiciou degradação da fração fibrosa e aumento no teor de PB, com efeito mais intenso nos tratamentos que usaram compostagem. A ação do fungo foi mais efetiva sobre a hemicelulose que sobre os demais componentes da fibra.The innoculation of forages with lignocellulolytic fungi is an option for improving quality without adding chemical products. Substrate quality influences fungal activity and endproduct quality. The effects of four treatments (composting of whole hay, composting of chopped hay, soaking in cool water and soaking in hot water on a Brachiaria decumbens hay were evaluated. The treatments were followed by innoculation with Pleurotus ostreatus

  4. 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.

  5. 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

  6. Brachiaria spp. poisoning of ruminants in Brazil

    OpenAIRE

    B. Riet-Correa; M.B. Castro; R.A. Lemos; G. Riet-Correa; V. Mustafa; F. Riet-Correa

    2011-01-01

    Brachiaria species are the most important grasses for cattle production in Brazil. However, a limiting factor for the use of Brachiaria spp. is their toxicity. Most outbreaks of hepatogenous photosensitization are caused by B. decumbens; however B. brizantha, B. humidicola and B. ruziziensis can also cause poisoning. The poisoning affects cattle, sheep, goats and buffalo. Sheep are more susceptible than other animal species and the young are more susceptible than adults. There are differences...

  7. 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

  8. Diazotrophic Bacterial Community of Degraded Pastures

    OpenAIRE

    João Tiago Correia Oliveira; Everthon Fernandes Figueredo; Williane Patrícia da Silva Diniz; Lucianne Ferreira Paes de Oliveira; Pedro Avelino Maia de Andrade; Fernando Dini Andreote; Júlia Kuklinsky-Sobral; Danúbia Ramos de Lima; Fernando José Freire

    2017-01-01

    Pasture degradation can cause changes in diazotrophic bacterial communities. Thus, this study aimed to evaluate the culturable and total diazotrophic bacterial community, associated with regions of the rhizosphere and roots of Brachiaria decumbens Stapf. pastures in different stages of degradation. Samples of roots and rhizospheric soil were collected from slightly, partially, and highly degraded pastures. McCrady’s table was used to obtain the Most Probable Number (MPN) of bacteria per gram ...

  9. 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

  10. 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

  11. Efeito do tratamento físico associado à adubação em pastagem degradada de braquiária, nos teores de proteína bruta, fibra em detergente neutro e fibra em detergente ácido Effect of the physical treatment associated to fertilization in degraded pastures of brachiaria grass on crude protein, neutral detergent fiber, and acid detergente fiber content

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    Erika Ramos Prazeres Bomfim

    2003-08-01

    Full Text Available Na região dos cerrados brasileiros, estima-se que atualmente existam 85 milhões de hectares ocupados com pastagens, dos quais 50 milhões de hectares são de pastagens cultivadas, sobretudo com gramíneas de origem africana do gênero Brachiaria, das quais mais de 50% estão degradadas ou em processo de degradação. Conduziu-se este trabalho com o objetivo de avaliar a influência do emprego de tratamentos físicos (grade intermediária e escarificador, de doses de nitrogênio (N e de fósforo (P, além das interações desses fatores na recuperação de uma pastagem degradada de braquiária (Brachiaria decumbens Stapf. Este experimento foi realizado em uma área de pastagem degradada do Departamento de Zootecnia da Universidade Federal de Lavras (UFLA, sul do estado de Minas Gerais, Brasil. O período experimental estendeu-se de dezembro de 1998 até abril de 2000. Foi utilizado um delineamento de blocos ao acaso, em esquema de parcelas subdivididas, alocando-se os tratamentos físicos nas parcelas e as adubações de N e P, nas subparcelas. A adubação baseou-se nos resultados da análise de solo e constou da aplicação de 100 kg/ha de N, 100 kg/ha de P2O5 e a combinação dessas duas doses. As aplicações de N e P elevaram os teores de proteína bruta, fibra em detergente ácido, e fibra em detergente neutro apenas em resposta ao P, no tecido vegetal de Brachiaria decumbens. Os tratamentos físicos influenciaram negativamente os teores de proteína bruta; contudo, a associação com o N reduziu esses efeitos negativos, elevando, porém, os teores de fibra em detergente neutro.ABSTRACT - In the Brazilian Cerrado, it is estimated that 85 millions ha exist with pastures with 50 millions ha under cultivated pastures, especially with African grasses of the genus Brachiaria. More than 50% of this pastures are degraded or under degradational process. The objective of this work was to evaluate the influence of physical treatments (offset disk

  12. 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.

  13. Brachiaria spp. poisoning of ruminants in Brazil

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    B. Riet-Correa

    2011-03-01

    Full Text Available Brachiaria species are the most important grasses for cattle production in Brazil. However, a limiting factor for the use of Brachiaria spp. is their toxicity. Most outbreaks of hepatogenous photosensitization are caused by B. decumbens; however B. brizantha, B. humidicola and B. ruziziensis can also cause poisoning. The poisoning affects cattle, sheep, goats and buffalo. Sheep are more susceptible than other animal species and the young are more susceptible than adults. There are differences in susceptibility among animals of the same species and it has been suggested that this resistance is genetic. Also has been suggested that buffalo and probably some sheep are resilient, i.e. when poisoned these animals have histologic lesions and high GGT serum concentrations, but do not show clinical signs. In general, saponin concentrations are higher in growing plants, but outbreaks occur all over the year, probably due to unexplained rise in saponin concentration in the plant. A clinical syndrome of progressive weight loss and death, without photosensitization, has been reported in cattle poisoned by B. decumbens. Main preventive measures are based on the selection of resistant or resilient animals and on the development of Brachiaria species or varieties with low saponin concentration.

  14. 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

    ="false" Priority="21" SemiHidden="false" UnhideWhenUsed="false" QFormat="true" Name="Intense Emphasis" />

    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

  15. 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

  16. Diazotrophic Bacterial Community of Degraded Pastures

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    João Tiago Correia Oliveira

    2017-01-01

    Full Text Available Pasture degradation can cause changes in diazotrophic bacterial communities. Thus, this study aimed to evaluate the culturable and total diazotrophic bacterial community, associated with regions of the rhizosphere and roots of Brachiaria decumbens Stapf. pastures in different stages of degradation. Samples of roots and rhizospheric soil were collected from slightly, partially, and highly degraded pastures. McCrady’s table was used to obtain the Most Probable Number (MPN of bacteria per gram of sample, in order to determine population density and calculate the Shannon-Weaver diversity index. The diversity of total diazotrophic bacterial community was determined by the technique of Denaturing Gradient Gel Electrophoresis (DGGE of the nifH gene, while the diversity of the culturable diazotrophic bacteria was determined by the Polymerase Chain Reaction (BOX-PCR technique. The increase in the degradation stage of the B. decumbens Stapf. pasture did not reduce the population density of the cultivated diazotrophic bacterial community, suggesting that the degradation at any degree of severity was highly harmful to the bacteria. The structure of the total diazotrophic bacterial community associated with B. decumbens Stapf. was altered by the pasture degradation stage, suggesting a high adaptive capacity of the bacteria to altered environments.

  17. 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

  18. Physiological and morphological responces of Brachiaria spp. to flooding Respostas morfológicas e fisiológicas de Brachiaria spp. ao alagamento do solo

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    MOACYR BERNARDINO DIAS-FILHO

    2000-10-01

    Full Text Available The physiological and morphological responses of the forage grasses Brachiaria brizantha cv. Marandu, B. decumbens and B. humidicola were compared for plants grown in pots under flooding and well-drained conditions for 14 days. Flooding reduced specific leaf area and biomass allocation to roots in all species and enhanced leaf senescence in B. brizantha and B. decumbens. Relative growth rate was reduced by flooding in B. brizantha and B. decumbens, but not in B. humidicola.Leaf elongation rate was unaffected by flooding in B. decumbens and B. humidicola, but declined in B. brizantha since the first day of flooding. Net photosynthesis and leaf chlorophyll content were reduced by flooding in B. brizantha; however, no flooding effect could be detected in the other two species. For all species, there was a close relationship between net photosynthesis and stomatal conductance under flooding. These results show that the studied species have distinct degrees of tolerance to flood, B. brizantha is intolerant, B. decumbens is moderately tolerant and B. humidicola is tolerant. Because leaf elongation rate was immediately depressed by flooding only in B. brizantha, this measurement could be appropriate as an early detection mechanism for relative flood tolerance in Brachiaria spp.As respostas morfológicas e fisiológicas de Brachiaria brizantha cv. Marandu, B. decumbens e B. humidicola foram comparadas em plantas cultivadas em vasos, sob solo alagado e bem drenado durante 14 dias. O alagamento reduziu a área foliar específica e a alocação de biomassa para as raízes em todas as três espécies e aumentou a senescência foliar em B. brizantha e B. decumbens. O alagamento reduziu a taxa de crescimento relativo em B. brizantha e B. decumbens, mas não em B. humidicola. A taxa de elongação foliar não foi afetada pelo alagamento em B. decumbens e B. humidicola, mas diminuiu em B. brizantha desde o primeiro dia de alagamento. A fotossíntese líquida e

  19. Hábito de pastejo de novilhas em pastagens do gênero Brachiaria - DOI: 10.4025/actascianimsci.v29i4.992 Grazing habits of heifers on pastures of Brachiaria genus - DOI: 10.4025/actascianimsci.v29i4.992

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    Juliana Silva de Oliveira

    2008-03-01

    Full Text Available Objetivou-se avaliar o comportamento de novilhas pastejando Brachiarias, em sistema de lotação contínua. O delineamento experimental foi o inteiramente casualizado, com duas espécies de gramíneas representando os tratamentos, cada um com cinco repetições. Foram utilizadas novilhas leiteiras, com peso vivo médio de 315 kg. O período experimental foi de 30 dias, sendo 20 para adaptação dos animais e 10 para avaliações, que consistiram de três, com duração de 24 horas cada, em intervalos de cinco dias. As novilhas pastejaram menos tempo no pasto de Brachiaria brizantha, com tempo de 10,56 horas, enquanto que o pastejo na Brachiaria decumbens foi de 11,51 horas. A quantidade de bocados por minuto foi menor para a Brachiaria decumbens, 31,27 horas, enquanto para a Brachiaria brizantha, as novilhas pastejaram com uma taxa de bocados de 37,72 bocados por minuto. As novilhas apresentam comportamento diferenciado nas gramíneas estudadas, elevando o tempo de pastejo na Brachiaria decumbens como forma de compensar um comportamento de pastejo mais seletivo.This work aimed to evaluate the grazing behavior of heifers on Brachiarias, in continuous stocking with variable stocking rates. The experimental design was completely randomized, with two pastures representing the treatments, each with five replications. Dairy heifers were used, with an average weight of 315 kg. The experiment lasted for 30 days, being 20 for adaptation of the animals and 10 for the three evaluations, each with a duration of 24 hours, in five-day intervals. Heifers grazed less time on the pasture of Brachiaria brizantha (10.56 hours, while the grazing on Brachiaria decumbens lasted 11.51 hours. Nevertheless, there was no difference for total bites. Heifers presented different grazing on the evaluated pastures, increasing grazing time on Brachiaria decumbens to adjust for a more selective behavior.

  20. 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, ...

  1. Intoxicação natural por Brachiaria spp. em ovinos no Brasil Central Brachiaria spp. poisoning in sheep in Central Brazil

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    Vanessa S. Mustafa

    2012-12-01

    Full Text Available Brachiaria spp. é a principal forrageira utilizada para ruminantes no Brasil Central, mas a sua toxicidade, devida à presença de saponinas esteroidais, torna-se um importante entrave à sua utilização. Neste trabalho descrevem-se 34 surtos e um foco de intoxicação por Brachiaria spp em ovinos, que ocorreram em diferentes épocas do ano. A morbidade geral foi de 23,2% e a letalidade foi 88,3%. O tempo que os animais permaneceram no pasto até o surgimento dos sinais clínicos da intoxicação por Brachiaria spp. variou de 15 dias até mais de 12 meses. Em 90,1% dos surtos os animais eram menores de 12 meses de idade. O curso clínico da intoxicação variou de 2 a 45 dias. Os sinais clínicos e as lesões macroscópicas foram características de fotossenssibilização hepatógena, no entanto, nos casos mais agudos não foram observadas dermatite nem icterícia, ocorrendo severo edema em face e orelhas. Na histologia do fígado as lesões mais características foram a presença de macrófagos com citoplasma espumoso, encontrados principalmente nos sinusoides hepáticos e, às vezes, com imagens negativas de cristais acutiformes no citoplasma. Em oito das 11 fazendas visitadas os surtos ocorreram em pastagens de Brachiaria decumbens; em duas em pastagens de B. brizantha e uma em pastagem de B. decumbens, B. humidicola e Andropogon sp. As concentrações de saponinas nas pastagens, em 5 surtos, variou de 0.3% a 2.56%. As informações geradas neste trabalho permitem a proposta de medidas para controle e profilaxia da intoxicação por Brachiaria spp. no Brasil Central.Brachiaria spp. is the main pasture for ruminants in Central-Brazil, but the crucial problem for their utilization is the toxicity due to the presence of steroidal saponins. This paper reports 35 outbreaks of poisoning by Brachiaria spp in sheep. The poisoning occurred in different seasons of the year. Mean morbidity was 23.2% and mean lethality was 88.3%. The occurrence of

  2. 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.

  3. Avaliação de fontes de urease na amonização de fenos de Brachiaria brizantha com dois teores de umidade Evaluation of urease sources in the ammoniation of Brachiaria brizantha hays with two moisture levels

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    Liandra Maria Abaker Bertipaglia

    2005-04-01

    Full Text Available O efeito da amonização com uréia (5,0% matéria seca do feno de Brachiaria brizantha, com dois teores de umidade (15 ou 30% de umidade, associado a três fontes de urease (feno de capim Brachiaria decumbens, capim-elefante [Pennisetum purpureum] e leucena [Leucaena leucocephala], foi avaliado. Foram determinados os teores de proteína bruta (PB, fração solúvel (A, frações de proteína verdadeira solúvel e insolúvel em borato fosfato (B1 e B2, fração de proteína potencialmente degradável (B3 e fração da proteína insolúvel em detergente ácido (C. Avaliaram-se os teores de fibra em detergente neutro (FDN, fibra em detergente ácido (FDA, celulose (CEL, hemicelulose (HEM e lignina (LIG e digestibilidade in vitro da matéria seca (DIVMS. O delineamento experimental foi o de blocos inteiramente casualizados, com 10 tratamentos (dois controles, 15 e 30% umidade, sem uréia e sem urease; dois controles, 15 e 30% umidade, com uréia e sem urease; seis combinações de fontes de urease e conteúdo de umidade e três repetições. A amonização dos fenos com diferentes conteúdos de umidade, associados a fontes de urease, aumentou os teores de PB e da fração A, mas não afetou B1 e B2. Contudo, as frações B3 e C diminuíram em reposta à amonização. A aplicação de uréia nos fenos de 30% de umidade, associados ou não a fontes de urease, diminuiu os teores de FDN. A adição de fontes de urease não alterou os teores dos constituintes da parede celular, quando comparada aos tratamentos amonizados com uréia. Os tratamentos aplicados não proporcionaram efeitos consistentes sobre os teores de FDA e de CEL dos fenos e não afetaram os teores de LIG. A aplicação de uréia associada a 15 ou 30% de umidade foi favorável para aumentar o nitrogênio solúvel do feno de Brachiaria brizantha e diminuir o nitrogênio indisponível para o ruminante.The urea ammoniation (5.0% dry matter effects in Brachiaria brizanta hay baled with two

  4. Intoxicação por Brachiaria spp. em bovinos no Mato Grosso do Sul Brachiaria spp. poisoning in cattle in Mato Grosso do Sul, Brazil

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    Roosevelt I.C. Souza

    2010-12-01

    Full Text Available 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 cinco o principal sinal foi o emagrecimento progressivo. Dos 24 surtos de fotossensibilização, 11 ocorreram em pastagens de B. decumbens, dois em pastagens mistas de B. decumbens e B. brizantha, um em B. brizantha e em 10 surtos não foi informada a espécie de Brachiaria envolvida. A morbidade variou de 0,2% a 50% e a letalidade de 44,4% a 100%. Nos casos de fotossensibilização o edema de barbela foi o sinal clínico mais encontrado em bovinos, seguido de dermatite com pele espessada no flanco e períneo, retração cicatricial auricular, icterícia, corrimento ocular. crostas auriculares e oculares, e ulcerações na parte ventral da língua. Em dois surtos foram observados sinais nervosos e em um, diarréia. Nas necropsias o fígado estava aumentado de tamanho, amarelado, com padrão lobular aumentado e, ocasionalmente, com áreas esbranquiçadas e deprimidas. Os rins estavam acastanhados e a urina escura. No exame histológico do fígado encontrou-se tumefação e vacuolização de hepatócitos, proliferação de células epiteliais dos ductos biliares, retenção biliar, fibroplasia periportal discreta ou moderada e infiltrado mononuclear periportal. Todos os casos de fotossensibilização apresentaram macrófagos espumosos no parênquima hepático e em 21 foram observados cristais birrefringentes nos ductos biliares. Cinco surtos com emagrecimento progressivo dos bovinos afetados foram diagnosticados em pastagens de B. decumbens. A

  5. Estrategias de enraizamiento de genotipos Brachiaria en suelos ácidos y de baja fertilidad en Colombia Rooting strategies of Brachiaria genotypes in acid and low fertility soils of Colombia

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    Jaumer Ricaurte

    Full Text Available En un Haplustox de los Llanos Orientales de Colombia se evaluaron durante 41 meses 6 genotipos de Brachiaria con resistencia variable a niveles altos de Al+3 en dos niveles de nutrientes. Los genotipos con resistencia media y alta mantuvieron altas producciones de biomasa aérea en los primeros meses, decrecieron a valores medios y estables hacia los 21 meses. La producción de biomasa y longitud de raíces en los genotipos de Brachiaria y especies de sabana nativa fue mayor en época lluviosa, con alta producción en los primeros 5 cm del perfil de suelo. Las gramíneas de la sabana nativa y B. decumbens CIAT 606 (altamente resistente a Al+3 generaron raíces finas y menor biomasa de raíces. Durante la época seca los genotipos de Brachiaria con resistencia media y alta a aluminio generaron raíces más profundas que la sabana nativa. La época seca indujo una producción de longitud y biomasa de raíces proporcionalmente más profundas que la lluviosa, tanto en genotipos de Brachiaria con resistencia media y alta a aluminio como en especies de la sabana nativa.In a Typic Haplustox soil in the “Altillanura” of the Eastern Plains (Llanos Orientales of Colombia Shoot biomass production was evaluated, during 41 months in 6 Brachiaria genotypes with variable resistance to high Al levels. with two nutrient levels. Moderate and highly Al-resistant Brachiaria genotypes maintained high shoot biomass production in early months of establishment, declined to medium values until 21 months. Root biomass and root length production of Brachiaria genotypes, as well as native savanna grasses, was greater during rainy season, with a high root production in the first 5 cm of the soil. Savanna species and the genotypes B. decumbens CIAT 606 (high Al+3 resistant produced finer roots and less root biomass than native savanna species. The dry season induced a proportional increase in deeper root length and biomass production compared with rainy season in both

  6. Restrição do 16S-23S DNAr intergênico para avaliação da diversidade de Azospirillum amazonense isolado de Brachiaria spp. Restriction of 16S-23S intergenic rDNA for diversity evaluation of Azospirillum amazonense isolated from different Brachiaria spp.

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    Fábio Bueno dos Reis Junior

    2006-03-01

    Full Text Available O objetivo deste trabalho foi avaliar a diversidade intra-específica de isolados de Azospirillum amazonense e estabelecer a possível influência de diferentes espécies de Brachiaria ssp. e diferentes condições edafoclimáticas. A caracterização da diversidade desses isolados foi conduzida, utilizando-se a análise de restrição da região intergênica 16S-23S DNAr. As estirpes estudadas separaram-se em dois grupos, definidos a 56% de similaridade. As espécies de Brachiaria ssp. influenciaram a diversidade de estirpes. A maioria dos isolados oriundos de B. decumbens e B. brizantha está inserida no primeiro grupo, enquanto os oriundos de B. humidicola concentram-se no segundo grupo.The aim of this work was to study the intra-specific diversity of Azospirillum amazonense isolates and to establish possible influences of different Brachiaria spp. and edaphoclimatic conditions. The characterization of the diversity among the isolates of A. amazonense studied was conducted using restriction analysis of the 16S-23S rDNA intergenic spacer region. The evaluated strains were separated in two groups, defined at 56% of similarity. Brachiaria spp. showed effects on strain diversity. Most part of the isolates from B. decumbens and B. brizantha are inserted in the first group, while B. humidicola isolates concentrate in the second group.

  7. Estrategias de enraizamiento de genotipos Brachiaria en suelos ácidos y de baja fertilidad en Colombia

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    Jaumer Ricaurte

    2007-09-01

    Full Text Available En un Haplustox de los Llanos Orientales de Colombia se evaluaron durante 41 meses 6 genotipos de Brachiaria con resistencia variable a niveles altos de Al+3 en dos niveles de nutrientes. Los genotipos con resistencia media y alta mantuvieron altas producciones de biomasa aérea en los primeros meses, decrecieron a valores medios y estables hacia los 21 meses. La producción de biomasa y longitud de raíces en los genotipos de Brachiaria y especies de sabana nativa fue mayor en época lluviosa, con alta producción en los primeros 5 cm del perfil de suelo. Las gramíneas de la sabana nativa y B. decumbens CIAT 606 (altamente resistente a Al+3 generaron raíces finas y menor biomasa de raíces. Durante la época seca los genotipos de Brachiaria con resistencia media y alta a aluminio generaron raíces más profundas que la sabana nativa. La época seca indujo una producción de longitud y biomasa de raíces proporcionalmente más profundas que la lluviosa, tanto en genotipos de Brachiaria con resistencia media y alta a aluminio como en especies de la sabana nativa.

  8. 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

  9. Armazenamento de sementes de braquiária peletizadas e tratadas com fungicida e inseticida Brachiaria coated seed storage treated with fungicide and insecticide

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    Carlos Eduardo Pereira

    2011-12-01

    Full Text Available A qualidade de sementes é fundamental para o sucesso da formação de pastagem, de forma que é importante viabilizar tecnologias para elas. Assim, objetivou-se com este trabalho avaliar o desempenho de sementes de Brachiaria decumbens peletizadas e tratadas com fungicida e inseticida, durante o armazenamento. As sementes foram tratadas com thiabendazol na dosagem de 200mL 100kg-1 de sementes, com fipronil na dosagem de 500mL 100kg-1 de sementes e com a mistura de ambos (nas mesmas dosagens e parte não foi submetida a esses tratamentos (testemunha. Posteriormente, as sementes foram peletizadas utilizando-se uma mistura de areia + microcelulose e cola Cascorex - PVA (20%, as quais em seguida foram armazenadas em condições ambientais em armazém convencional (temperatura e umidade relativa do ar média de 21,9°C e 68%, respectivamente, durante 12 meses. As sementes foram avaliadas inicialmente e a cada quatro meses com as seguintes avaliações: teor de água, teste de germinação, índice de velocidade de germinação, teste de emergência e índice de velocidade de emergência. A peletização das sementes de Brachiaria decumbens com areia e microcelulose prejudica a porcentagem e velocidade de germinação, bem como a emergência de plântulas durante o armazenamento. Sementes de Brachiaria decumbens cv. 'Basilisk' tratadas com fipronil, thiabendazol, ou com ambos, não devem ser armazenadas por mais de oito meses.The quality of seed is crucial to the success of pasture formation. Thus the aim of this research was to evaluate the performance of Brachiaria decumbens seeds pelleted and treated with fungicides and insecticides during storage. The seeds were treated with thiabendazole at a dosage of 200mL 100kg-1 of seeds, with fipronil at a dosage of 500mL 100kg-1 of seeds and a mixture of both (in the same dosages and some was not subjected to such treatment (control. Subsequently the seeds were coated using a mixture of sand

  10. 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.

  11. Renovação de pastagem degradada com calagem, adubação e leguminosa consorciada em Neossolo Quartzarênico = Degraded pasture recovering with liming, fertilization, and associated legume in Quartzipsament

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    Edimilson Volpe

    2008-01-01

    Full Text Available A degradação é considerada o maior problema das pastagens cultivadas no Cerrado. Em Neossolo Quartzarênico, foi conduzido um experimento para avaliar diversos tratamentos de renovação de pastagem degradada de Brachiaria decumbens, introduzindo Brachiaria brizantha cv. Marandu. Os tratamentos foram: Testemunha; Calagem; Calagem +P; Calagem + ½(PK; Calagem + PK; Calagem + PK + Micronutrientes; Calagem + PK + Micronutrientes + Leguminosa. O delineamento experimental foi de blocos casualizados, com quatro repetições. Realizaram-se três cortes, em 325 dias, e, ao final, avaliação da produção de raízes e análise química do solo. Todos os tratamentos derenovação diferiram da testemunha e alguns deles diferiram entre si na produção de massa seca da parte aérea, destacando-se o tratamento com leguminosa. A produção de raízes foi significativamente superior em três tratamentos quando comparados à testemunha. Foramverificados aumentos significativos nos teores de nutrientes e pH do solo, com a aplicação de calcário e fertilizantes.The degradation is considered to be the major problem of cultivated pastures in the Cerrado. In Quartzipsament, an experiment wasconducted to evaluate several degraded pasture recovering treatments of Brachiaria decumbens, introducing Brachiaria brizantha cv. Marandu. The treatments were: Witness; Liming; Liming + P; Liming + ½(PK; Liming + PK. Liming + PK + Micronutrients; Liming + PK + Micronutrients + Legume. The experimental design was that ofrandomized blocks with four replications. Three cuts in a 325 days period were done and, in the end, the evaluation of roots production and soil chemical analysis. All renovation systems differed from the witness and some of them differed among themselves in terms ofdry mass of aerial portion, with emphasis to the legume treatment. The roots production was significantly greater in three treatments when compared to the witness. Significant increases in the

  12. Rooting strategies of Brachiaria genotypes in acid and low fertility soils of Colombia Estrategias de enraizamiento de genotipos Brachiaria en suelos ácidos y de baja fertilidad en Colombia

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    Menjivar Juan Carlos

    2007-09-01

    Full Text Available In a Typic Haplustox soil in the “Altillanura” of the Eastern Plains (Llanos Orientales of Colombia Shoot biomass production was evaluated, during 41 months in 6 Brachiaria genotypes with variable resistance to high Al levels. with two nutrient levels. Moderate and highly Al-resistant Brachiaria genotypes maintained high shoot biomass production in early months of establishment, declined to medium values until 21 months. Root biomass and root length production of Brachiaria genotypes, as well as native savanna grasses, was greater during rainy season, with a high root production in the first 5 cm of the soil. Savanna species and the genotypes B. decumbens CIAT 606 (high Al+3 resistant produced finer roots and less root biomass than native savanna species. The dry season induced a proportional increase in deeper root length and biomass production compared with rainy season in both moderately and highly Al-resistant Brachiaria genotypes as well as in native savanna species.En un Haplustox de los Llanos Orientales de Colombia se evaluaron durante 41 meses 6 genotipos de Brachiaria con resistencia variable a niveles altos de Al+3 en dos niveles de nutrientes. Los genotipos con resistencia media y alta mantuvieron altas producciones de biomasa aérea en los primeros meses, decrecieron a valores medios y estables hacia los 21 meses. La producción de biomasa y longitud de raíces en los genotipos de Brachiaria y especies de sabana nativa fue mayor en época lluviosa, con alta producción en los primeros 5 cm del perfil de suelo. Las gramíneas de la sabana nativa y B. decumbens CIAT 606 (altamente resistente a Al+3 generaron raíces finas y menor biomasa de raíces. Durante la época seca los genotipos de Brachiaria

  13. 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

  14. Silicon accumulation and water deficit tolerance in Brachiaria grasses Acúmulo de silício e tolerância ao déficit hídrico em capins do gênero Brachiaria

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    Suzana Pereira de Melo

    2003-12-01

    Full Text Available The beneficial effects of silicon (Si fertilization have been observed for several plant species, especially when submitted to stress, either biotic or abiotic. Among the possible reasons for the greater adaptability and resistance of brachiaria grass in areas of low fertility soils in Brazilian savanna, stands its capacity of absorbing and accumulating Si in aerial parts. To evaluate the effect of Si on dry matter yield of Brachiaria decumbens Stapf and Brachiaria brizantha Hochst, grown under two soil moisture regimes, a trial was set up in a completely randomized design factorial scheme (5 × 2 × 2, with five Si rates: (0; 242; 484; 968 and 1,452 kg ha-1, two soil water tensions (60% and 80% of field capacity and the two brachiaria species. The experiment was installed in a greenhouse, using one of the most representative soils in the region under cerrado, Typic Haplustox. Both brachiaria species can be considered Si-accumulating plants, since they present high Si contents in their aerial parts. Application of Si to the soil increased the contents of this element in both grass species but did not change their tolerance to water deficit, and did not affect dry matter yield.Efeitos benéficos da adubação com silício (Si têm sido observados em várias espécies vegetais, especialmente quando estas estão submetidas a estresse biótico ou abiótico. Entre as possíveis razões para a maior adaptabilidade e resistência do capim braquiária nas áreas de baixa fertilidade do solo das regiões do cerrado brasileiro, esta associada à sua capacidade em absorver e acumular Si na parte aérea. Este trabalho teve como objetivo avaliar o efeito da aplicação de Si sobre a produção de matéria seca de duas espécies das gramíneas Brachiaria decumbens Stapf e Brachiaria brizantha Hochst, cultivadas sob dois regimes de umidade no solo. Os ensaios foram instalados em delineamento inteiramente casualizado, em esquema fatorial (5 × 2 × 2 com cinco

  15. 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.

  16. Purification and characterization of lignin peroxidases from Penicillium decumbens P6

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    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.

  17. 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.

  18. 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...

  19. 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

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. Crescimento de espécies do gênero Brachiaria, sob déficit hídrico, em casa de vegetação Effect of water deficit on the growth of Brachiaria species in greenhouse

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    Jorge Luiz Schirmer de Mattos

    2005-06-01

    Full Text Available Avaliaram-se as características morfogênicas, fisiológicas e produtivas de espécies de Brachiaria, durante e após período de estresse hídrico. Os tratamentos foram arranjados em um esquema fatorial 4 x 5 quatro espécies de Brachiaria (B. decumbens, B. brizantha, B. humidicola e B. mutica e cinco níveis de potencial hídrico do solo (-0, 01, -0, 03, -0, 1, -0, 5 e -1, 5 MPa em um delineamento experimental de blocos ao acaso, com três repetições. O experimento foi instalado em casa de vegetação, em colunas de PVC com 40 cm de altura e 30 cm de diâmetro. Os déficits hídricos foram impostos durante 23 dias e, após este período, um grupo de plantas foi mantido sob condições normais de disponibilidade de água no solo, durante, aproximadamente, uma semana, para se avaliar a capacidade de recuperação das plantas. A taxa de alongamento das lâminas foliares foi comprometida em B. brizantha e a taxa de senescência de lâminas foliares em B. mutica foi aumentada com o decréscimo do potencial hídrico no solo, denotando a maior sensibilidade destas duas espécies ao déficit hídrico. Observou-se controle estomático sobre as trocas gasosas em folhas de todas as espécies. O déficit hídrico reduziu a fotossíntese líquida em todas espécies, mais acentuadamente em B. mutica e B. humidicola. Todas as espécies recuperaram suas atividades fotossintéticas normais após o déficit hídrico, mas apenas a B. brizantha restabeleceu o status hídrico de seus tecidos foliares. O déficit hídrico afetou mais acentuadamente a área de lâminas foliares verdes em B. brizantha e B. decumbens, a produção de matéria verde seca de lâminas foliares em todas as espécies estudadas, e a produção de matéria verde seca de colmos em B. decumbens e B. mutica.This study aimed to evaluate the tolerance of Brachiaria species (B. decumbens, B. brizantha, B. humidicola and B. mutica to low soil water potential. Morphogenetical, physiological and

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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.

  10. 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

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. 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.

  16. 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

  17. 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

  18. 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

    OpenAIRE

    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...

  19. 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.

  20. 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.

  1. 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 ...

  2. 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.

    186 accesiones de 9 especies de Brachiaria, se establecieron en un diseño de franjas divididas, con 2 repeticiones, para evaluar 2 niveles de fertilidad: a el recomendado para establecer pasturas; b el nivel para establecer un sistema integrado arroz-pastos. En el tercer año se evaluó el potencial de rendimiento de semillas. En las pruebas de germinación y latencia se evaluó el efecto de 2 tratamientos: 1 Agua y 2 Semilla escarificada en ácido sulfúrico; las de b. humidicola se trataron con Nitrato de Potasio. El rendimiento promedio y el Peso Unidad de las semillas no presentaron diferencias significativas (P<0.05 por efecto del nivel de fertilidad. Las semillas de B. decumbens, sin tratamiento, germinaron 0.3% a los 11 meses y se incrementó a 38.3% cuando se escarificaron; B. dictyoneura alcanzó la mayor germinación (69.3% a los 14 meses, y B. humidicola (52.1% a los 11meses. En B. brizantha y B. jubata se presentaron incrementos de 32.8 y 21.3% respectivamente, a los 14 meses.

  3. 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.

  4. 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

  5. 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

    Directory of Open Access Journals (Sweden)

    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

  6. 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

  7. 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...

  8. 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

    Directory of Open Access Journals (Sweden)

    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

  9. 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

    Directory of Open Access Journals (Sweden)

    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

  10. 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.

  11. 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.

  12. 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

    Directory of Open Access Journals (Sweden)

    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

  13. 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

  14. 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)

  15. 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.

  16. 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

    Directory of Open Access Journals (Sweden)

    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

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  19. 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

  20. 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

    Directory of Open Access Journals (Sweden)

    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

  1. 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

    Directory of Open Access Journals (Sweden)

    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

  2. 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

  3. 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...

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

    OpenAIRE

    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.

  5. 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

  6. 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

  7. 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.

  8. 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

  9. 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

  10. 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.

  11. 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

  12. 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’.

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

    Science.gov (United States)

    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.

  14. 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

    Directory of Open Access Journals (Sweden)

    Benir de Oliveira

    2007-09-01

    Full Text Available

    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%.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  17. 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...

  18. 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.

  19. 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

    Full Text Available

    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

  20. 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

  1. 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.

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

    International Nuclear Information System (INIS)

    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)

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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

  11. 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.

  12. 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

  13. 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.

  14. 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 

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

    Science.gov (United States)

    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.

  16. 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.

  17. 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

  18. 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

  19. 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.

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

    Science.gov (United States)

    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.

  1. 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.

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

    OpenAIRE

    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...

  3. 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.

  4. 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.

  5. 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

    Directory of Open Access Journals (Sweden)

    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

  6. 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)

  7. 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

  8. 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

  9. 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

    Directory of Open Access Journals (Sweden)

    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.

  10. 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.

  11. 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

    Directory of Open Access Journals (Sweden)

    Avílio Antonio Franco

    2007-09-01

    Full Text Available

    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

  12. 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.

  13. 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

  14. 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

  15. 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

  16. 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.

  17. 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.

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

    Science.gov (United States)

    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.

  19. 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.

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

    Science.gov (United States)

    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.

  1. 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

  2. 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

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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

  11. 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

  12. 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.

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

    International Nuclear Information System (INIS)

    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)

  14. 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.

  15. 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.

  16. 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

  17. Biological fixation of nitrogen in three tropical feed crops leguminous and its transfer to Brachiaria humidicola in association

    International Nuclear Information System (INIS)

    Gil, Jose Luis; Guenni, Orlando; Espinoza, Yusmary

    1997-01-01

    In Cojedes State drained savannas an experiment was carried out with the purpose of: a) to determine the biological fixation of nitrogen (BFN) in three tropical feed crops leguminous (Centrosema pubescens Cp, Stylosanthes hamata Sh and Pueraria phaseoloides, Pp) cultivated in monoculture and associated with the gramineous Brachiaria humidicola (Bh); b) to evaluate the transfer potential of N fixed to the air to the companion gramineous. To calculate the proportion of N biologically fixed, the technique of isotopic dilution was used with N 1 5. The fertilizer (enriched ammonium sulphate to 10% with N 1 5) was added during the rainy season in two regrowth periods. In each case, the aerial biomass was determined after 90 days of growth, being analyzed the total content of N and N 1 5 in the foliage. In both periods of evaluation, the association Bh / Cp was stabler, with a proportion of the leguminous in the mixture 20-30%. As monoculture, Bh had the biggest production of aerial biomass (972 gm -2 ) among all the treatments for the first period of evaluation (middle rainy season). The total production of dry matter (DM) in association, was modified between 574 (Bh/Cp) and 807 gm -2 (Bh/Sh). The production DM for the second period of evaluation (end rainy season) followed the same tendency, being observed, however, a general decrease in the yields due to the beginning of drought. The content of N in the leguminous was always higher than in Bh. Nevertheless, Bh in association reached an accumulation bigger than N (14 gm -2 ) due to its higher rate of growth. The leguminous alone had a significant proportion of N (47-69%) derivated of the BFN. Cp was the one that showed higher values of BFN (51-69%). Likewise, one observes a high proportion (57-76%) of element starting from the BFN when the leguminous were cultivated in association. In this sense one doesn't observe a clear transfer of N from the leguminous to the gramineous, since the contents of N 1 5 in Bh they were

  18. 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; ...

  19. 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 ...

  20. Efectividad de métodos de control de malezas en la producción de forraje del pasto Pangola (Digitaria decumbens Stent.

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    Valent\\u00EDn Alberto Esqueda-Esquivel

    2007-01-01

    Full Text Available Efectividad de métodos de con trol de ma le zas en la producción de forraje del pasto Pangola (Digitaria decumbens Stent. En el periodo de agosto de 1998 a agosto de 1999 se condujo un experimento en Emilio Carranza, municipio de Ve ga de Alatorre, Ve racruz, México, con el objeto de determinar el efec to de tra ta mien tos de con trol quí mi co y ma nual de ma le zas en la pro duc ción de fo rraje de zacate Pangola y en la den si dad de po bla ción de ma le zas presentes al inicio del siguiente ciclo de lluvias. Se utilizó el diseño experimental de blo ques completos al azar con cua tro re pe ti cio nes. Los tra tamien tos evaluados fueron: 1. Mezcla for mulada de picloram + 2,4-D (64 + 240 g/100 l agua 2. Mez cla for mu la da de pi cloram + flu ro xi pir (40 + 40 g/100 l agua 3. Con trol ma nual mediante chapeo con machete y 4. Testigo enhierbado. Las parcelas experimentales tuvieron 30 m de longitud y 10 m de anchura. Los tra ta mien tos 1, 2 y 3 se apli ca ron el 17 de agos to de 1998, cuan do la zar za de lo ma (Mimosa albida, que fue la es pe cie de ma le za do mi nan te te nía en tre 40 y 60 cm de al tu ra y la cobertura promedio de malezas del lote experimental, era de 57,9%. Se eva luó la co ber tu ra de ma le zas y pas to y el control de ma le zas a los 29, 60, 80, 114 y 154 días des pués de la aplicación de los tratamientos (DDA. También se determinó la producción de forraje de za ca te Pan go la a los 45, 80, 143 y 178 DDA. Con pi clo ram + flu ro xi pir y pi clo ram + 2,4-D, se controló más eficientemente a M. albida y el com ple jo de ma le zas her bá ceas que con el cha peo y se ob tu vo una produc ción significativamente mayor de ma teria seca de pas to. Ambos tratamientos herbicidas presentaron menor densidad de po bla ción de ma le zas en el si guien te ci clo de llu vias que el tratamiento con chapeo.

  1. 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.

  2. 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.

  3. 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

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    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

  4. Fotossensibilização em ovinos associada à ingestão de Brachiaria brizantha no estado do Pará Photosensitization of sheep kept on Brachiaria brizantha pasture in the state of Pará

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    Tatiane Teles Albernaz

    2010-09-01

    Full Text Available Foram estudados dois surtos e realizado um experimento de fotossensibilização associada à ingestão por Brachiaria brizantha em ovinos mestiços de Santa Inês e Dorper, com idade variando de dois a três meses, em uma fazenda no município de Santa Luzia do Pará. Esses animais foram mantidos desde o nascimento até aproximadamente dois meses de idade, em apriscos suspensos do chão, recebendo capim-elefante roxo (Pennisetum purpureum cv. roxo, concentrado, sal mineral e água ad libitum. Após esse período foram introduzidos em um piquete de B. brizantha. Na ocasião dos surtos e do experimento a fazenda foi visitada para observação dos dados epidemiológicos, avaliação clínica dos animais, colheita de amostras de sangue para dosagem de GGT, AST, BD, BI, BT, ureia e creatinina e colheita de pastagem para pesquisa de Pithomyces chartarum e saponinas. Também foi realizada necropsia com colheita de material para estudo histológico. O surto 01 ocorreu na época de escassez de chuva, com taxa de morbidade e letalidade de 43,4% e 81,6%, respectivamente. O surto 02 aconteceu no início da época chuvosa, com taxas de morbidade e letalidade de 16,3% e 76,9%, respectivamente. Em ambos os surtos o capim encontrava-se com massa residual reduzida e senescente. Dos 50 animais do experimento, 10 receberam 200ml de fluido ruminal retirado de ovelhas mães do mesmo lote, a primeira administração foi feita um dia antes da introdução desses animais na pastagem, e mais duas subsequentes com intervalo de uma semana. Após 15 dias de pastejo, os animais começaram a apresentar inquietação, procura por sombra, edema nas orelhas, mucosas amareladas, apatia, anorexia e desprendimento da pele seguido por formação de crostas em algumas áreas do corpo. Tanto os animais dos surtos quanto do experimento apresentaram aumento nos níveis de GGT, AST, BD, BI, BT, ureia e creatinina. Os valores de ureia e GGT dos animais que receberam fluido ruminal e dos

  5. 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.

  6. EFFECT OF DIFFERENT PHOSPHORUS SOURCES IN BRACHIARIA BRIZANTHA CV. MARANDU CULTIVATED IN TWO SOILS EFEITO DE DIFERENTES FONTES DE FÓSFORO NA Brachiaria Brizantha CV. MARANDU CULTIVADA EM DOIS TIPOS DE SOLOS

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    Mozart Martins Ferreira

    2007-07-01

    Full Text Available The experiment was carried out at the Soil Science Department of the Federal University of Lavras, with the objective to evaluate the effect of the furnishment of different phosphorus (P sources, during the implantation of Bracharia brizantha in the accumulation of phosphorus (P, nitrogen (N content and shoot’s dry matter production (SDMP. The forage was grown in two distinct soils, a clayey dystrophic Red Latosol (Oxisol- LVdf and in a sandy Neosol (Entisol- NQ, for 180 days, in pots (3 dm3. Four different phosphorus sources were evaluated: triple superphosphate (TS - 46.1% total P2O5, Arad reactive phosphate (AR - 33. 1% total P2O5, Araxá natural phosphate (AN - 22.71% total P2O5, and a 1:1 ratio mixture TS/AR (1:1 total P2O5. Each P-source furnished 200 and 350 mg kg-1 of P2O5, for the NQ and LVdf soils, respectively, based on the each source’s P2O5 total content. The experimental design was a completely randomized in 4x2 scheme, with four replicates. Based on the nitrogen (N complementary fertilization, applied after each cut, high shoot’s N content were found ranging from 1.32 to 2.6 g/kg for the LVdf soil and 1.01 to 2.82 g/kg for the NQ soil, such that values for crude protein ranged from 8.25 to 16.25% and 6.31 to 17.62% for the LVdf and NQ soils respectively. Soil’s distinct mineralogy influenced Braquiaria response to the different P sources furnished. Considering that the shoot’s dry matter production (SDMP was higher in the NQ soil, and the total P accumulation after four cuts was higher in the LVdf soil. The use of P- sources of higher solubility promoted higher values for SDMP. High values for brachiaria N content were observed under the addition of low solubility P-sources such as, AR and AN. Growth and dry matter production were limited by the lack of phosphorus in the grass’s establishment. KEY-WORDS: Concentration, solubility, crude protein, forage, phosphate fertilization. O experimento foi realizado no

  7. 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.

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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

    Full Text Available

    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

  14. 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

    Full Text Available

    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.

    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.

  15. Performance of dairy heifers raised on Xaraés palissadgrass (Brachiaria brizantha cv. Xaraés pasture supplemented with two types of mineral mixture

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    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.

  16. 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

  17. 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

  18. 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.

  19. 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.

  1. 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

    Full Text Available

    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

  2. Degradations and Rearrangement Reactions

    Science.gov (United States)

    Zhang, Jianbo

    This section deals with recent reports concerning degradation and rearrangement reactions of free sugars as well as some glycosides. The transformations are classified in chemical and enzymatic ways. In addition, the Maillard reaction will be discussed as an example of degradation and rearrangement transformation and its application in current research in the fields of chemistry and biology.

  3. Efeito residual da silicatagem no solo e na produtividade do capim-marandu sob pastejo Residual effect of silicate application on soil and brachiaria grass yield under grazing

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    Letícia de Abreu Faria

    2008-06-01

    Full Text Available A escória siderúrgica é uma alternativa para a correção da acidez dos solos e é constituída de silicato de cálcio. Neste estudo, avaliaram-se os efeitos residuais da aplicação de silicato de cálcio nos atributos químicos do solo e da planta em Latossolo Vermelho distroférrico típico com capim-Marandu (Brachiaria brizantha cv. Marandu, sob intensidades de pastejo em lotação rotacionada. O delineamento experimental foi de blocos ao acaso, com intensidades de pastejo avaliadas pelas ofertas diárias de forragem de 50, 100, 150 e 200 kg t-1 de MS por PV nas parcelas experimentais, enquanto a aplicação superficial de silicato de cálcio combinado com calcário dolomítico, respectivamente, nas doses 0 + 0; 2 + 0; 4 + 0; 6 + 0; 2 + 4; 4 + 2 e 0 + 6 t ha- 1 nas subparcelas com quatro repetições, duas épocas (verão e inverno e avaliação em três profundidades do solo (0-10, 10-20 e 20-40 cm. Os atributos químicos do solo pH em CaCl2, Ca, Mg, K, H + Al e V, avaliados 720 dias após a aplicação, apresentaram resultados favoráveis do poder residual do silicato de Ca e do calcário. A oferta de forragem 200 kg t-1 e o tratamento somente com calcário dolomítico (0 + 6 t ha-1 elevaram o valor de pH em CaCl2 e o V, principalmente na camada de 0-10 cm. Os teores de Si no solo foram influenciados pelas doses aplicadas de silicato de Ca, apesar de não terem causado alterações significativas nos teores foliares de Si. A composição químico-bromatológica foi afetada somente pelas ofertas e épocas. As ofertas, épocas e a interação época x oferta resultaram em efeitos na produção de matéria seca no pré-pastejo, com maiores produções para a oferta 200 kg t-1 e menores para a de 50 kg t-1 nas duas épocas. O resíduo (pós-pastejo foi influenciado pelas ofertas e épocas. As ofertas 50 e 100 kg t-1 e o tratamento com 2 t ha-1 de silicato de Ca promoveram as maiores taxas de acúmulo de matéria seca.Basic slag consists of

  4. 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.

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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

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    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

  10. 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

    Directory of Open Access Journals (Sweden)

    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

  11. 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

    Directory of Open Access Journals (Sweden)

    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

  12. 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

    Directory of Open Access Journals (Sweden)

    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

  13. How do polymers degrade?

    Science.gov (United States)

    Lyu, Suping

    2011-03-01

    Materials derived from agricultural products such as cellulose, starch, polylactide, etc. are more sustainable and environmentally benign than those derived from petroleum. However, applications of these polymers are limited by their processing properties, chemical and thermal stabilities. For example, polyethylene terephthalate fabrics last for many years under normal use conditions, but polylactide fabrics cannot due to chemical degradation. There are two primary mechanisms through which these polymers degrade: via hydrolysis and via oxidation. Both of these two mechanisms are related to combined factors such as monomer chemistry, chain configuration, chain mobility, crystallinity, and permeation to water and oxygen, and product geometry. In this talk, we will discuss how these materials degrade and how the degradation depends on these factors under application conditions. Both experimental studies and mathematical modeling will be presented.

  14. 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

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

    Directory of Open Access Journals (Sweden)

    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

  16. Bacteria and lignin degradation

    Institute of Scientific and Technical Information of China (English)

    Jing LI; Hongli YUAN; Jinshui YANG

    2009-01-01

    Lignin is both the most abundant aromatic (phenolic) polymer and the second most abundant raw material.It is degraded and modified by bacteria in the natural world,and bacteria seem to play a leading role in decomposing lignin in aquatic ecosystems.Lignin-degrading bacteria approach the polymer by mechanisms such as tunneling,erosion,and cavitation.With the advantages of immense environmental adaptability and biochemical versatility,bacteria deserve to be studied for their ligninolytic potential.

  17. FERTILIZATION AND PLANT ARRANGEMENT IN INTERCROPPED MAIZE AND BRACHIARIA ADUBAÇÃO E ARRANJO DE PLANTAS NO CONSÓRCIO MILHO E BRAQUIÁRIA

    Directory of Open Access Journals (Sweden)

    Luis Fabio Ribeiro

    2008-11-01

    -height:150%; mso-pagination:widow-orphan; text-autospace:none; font-size:10.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";} p.Assuntodocomentrio, li.Assuntodocomentrio, div.Assuntodocomentrio {mso-style-name:"Assunto do comentário"; mso-style-parent:"Texto de comentário"; mso-style-next:"Texto de comentário"; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:EN-US; mso-fareast-language:EN-US; font-weight:bold;} span.style18 {mso-style-name:style18;} ins {mso-style-type:export-only; text-decoration:none;} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} -->

    The optimization of maize and Brachiaria intercropping managment is influenced by soil fertility, Brachiaria plant density, and maize plant arrangement. This research evaluated those factors interactions and their influence on the productivity of maize and Brachiaria. The experiment was carried out during two crop cycles, in a 2x2x3+1 factorial scheme, combining two conditions of maize fertilization (grain yield expectation of 6 or > 10 t ha-1, medium or high plant density of Brachiaria (< 20 or > 30 plant m-2, three maize plant arrangements (A = 90 cm row spacing with 5 plants m-1; B = 45 cm row spacing with 2.5 plants m-1; and C = 45 cm row spacing with 3 plants m-1, and one additional treatment (heavier fertilization, without Brachiaria and maize A arrangement. Water availability influenced the responses to treatments. In the rainy year, heavier fertilization promoted expressive grain yield increase

  18. 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

  19. 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

  20. 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)

  1. Motor degradation prediction methods

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, J.R.; Kelly, J.F.; Delzingaro, M.J.

    1996-12-01

    Motor Operated Valve (MOV) squirrel cage AC motor rotors are susceptible to degradation under certain conditions. Premature failure can result due to high humidity/temperature environments, high running load conditions, extended periods at locked rotor conditions (i.e. > 15 seconds) or exceeding the motor`s duty cycle by frequent starts or multiple valve stroking. Exposure to high heat and moisture due to packing leaks, pressure seal ring leakage or other causes can significantly accelerate the degradation. ComEd and Liberty Technologies have worked together to provide and validate a non-intrusive method using motor power diagnostics to evaluate MOV rotor condition and predict failure. These techniques have provided a quick, low radiation dose method to evaluate inaccessible motors, identify degradation and allow scheduled replacement of motors prior to catastrophic failures.

  2. Endocytic collagen degradation

    DEFF Research Database (Denmark)

    Madsen, Daniel H.; Jürgensen, Henrik J.; Ingvarsen, Signe Ziir

    2012-01-01

    it crucially important to understand both the collagen synthesis and turnover mechanisms in this condition. Here we show that the endocytic collagen receptor, uPARAP/Endo180, is a major determinant in governing the balance between collagen deposition and degradation. Cirrhotic human livers displayed a marked...... up-regulation of uPARAP/Endo180 in activated fibroblasts and hepatic stellate cells located close to the collagen deposits. In a hepatic stellate cell line, uPARAP/Endo180 was shown to be active in, and required for, the uptake and intracellular degradation of collagen. To evaluate the functional...... groups of mice clearly revealed a fibrosis protective role of uPARAP/Endo180. This effect appeared to directly reflect the activity of the collagen receptor, since no compensatory events were noted when comparing the mRNA expression profiles of the two groups of mice in an array system focused on matrix-degrading...

  3. Degradation of fluorotelomer alcohols

    DEFF Research Database (Denmark)

    Ellis, David A; Martin, Jonathan W; De Silva, Amila O

    2004-01-01

    Human and animal tissues collected in urban and remote global locations contain persistent and bioaccumulative perfluorinated carboxylic acids (PFCAs). The source of PFCAs was previously unknown. Here we present smog chamber studies that indicate fluorotelomer alcohols (FTOHs) can degrade...... in the atmosphere to yield a homologous series of PFCAs. Atmospheric degradation of FTOHs is likely to contribute to the widespread dissemination of PFCAs. After their bioaccumulation potential is accounted for, the pattern of PFCAs yielded from FTOHs could account for the distinct contamination profile of PFCAs....... The significance of the gas-phase peroxy radical cross reactions that produce PFCAs has not been recognized previously. Such reactions are expected to occur during the atmospheric degradation of all polyfluorinated materials, necessitating a reexamination of the environmental fate and impact of this important...

  4. Motor degradation prediction methods

    International Nuclear Information System (INIS)

    Arnold, J.R.; Kelly, J.F.; Delzingaro, M.J.

    1996-01-01

    Motor Operated Valve (MOV) squirrel cage AC motor rotors are susceptible to degradation under certain conditions. Premature failure can result due to high humidity/temperature environments, high running load conditions, extended periods at locked rotor conditions (i.e. > 15 seconds) or exceeding the motor's duty cycle by frequent starts or multiple valve stroking. Exposure to high heat and moisture due to packing leaks, pressure seal ring leakage or other causes can significantly accelerate the degradation. ComEd and Liberty Technologies have worked together to provide and validate a non-intrusive method using motor power diagnostics to evaluate MOV rotor condition and predict failure. These techniques have provided a quick, low radiation dose method to evaluate inaccessible motors, identify degradation and allow scheduled replacement of motors prior to catastrophic failures

  5. Ecosystem degradation in India

    International Nuclear Information System (INIS)

    Sinha, B.N.

    1990-01-01

    Environmental and ecosystem studies have assumed greater relevance in the last decade of the twentieth century than even before. The urban settlements are becoming over-crowded and industries are increasingly polluting the air, water and sound in our larger metropolises. Degradation of different types of ecosystem are discussed in this book, Ecosystem Degradation in India. The book has been divided into seven chapters: Introduction, Coastal and Delta Ecosystem, River Basin Ecosystem, Mountain Ecosystem, Forest Ecosystem, Urban Ecosystem and the last chapter deals with the Environmental Problems and Planning. In the introduction the environmental and ecosystem degradation problems in India is highlighted as a whole while in other chapters mostly case studies by experts who know their respective terrain very intimately are included. The case study papers cover most part of India and deal with local problems, stretching from east coast to west coast and from Kashmir to Kanyakumari. (author)

  6. PWR degraded core analysis

    International Nuclear Information System (INIS)

    Gittus, J.H.

    1982-04-01

    A review is presented of the various phenomena involved in degraded core accidents and the ensuing transport of fission products from the fuel to the primary circuit and the containment. The dominant accident sequences found in the PWR risk studies published to date are briefly described. Then chapters deal with the following topics: the condition and behaviour of water reactor fuel during normal operation and at the commencement of degraded core accidents; the generation of hydrogen from the Zircaloy-steam and the steel-steam reactions; the way in which the core deforms and finally melts following loss of coolant; debris relocation analysis; containment integrity; fission product behaviour during a degraded core accident. (U.K.)

  7. Antifoam degradation testing

    Energy Technology Data Exchange (ETDEWEB)

    Lambert, D. P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River Ecology Lab. (SREL); Zamecnik, J. R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River Ecology Lab. (SREL); Newell, D. D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River Ecology Lab. (SREL); Williams, M. S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River Ecology Lab. (SREL)

    2015-08-20

    This report describes the results of testing to quantify the degradation products resulting from the dilution and storage of Antifoam 747. Antifoam degradation is of concern to the Defense Waste Processing Facility (DWPF) due to flammable decomposition products in the vapor phase of the Chemical Process Cell vessels, as well as the collection of flammable and organic species in the offgas condensate. The discovery that hexamethyldisiloxane is formed from the antifoam decomposition was the basis for a Potential Inadequacy in the Safety Analysis declaration by the DWPF.

  8. Detection of pump degradation

    International Nuclear Information System (INIS)

    Casada, D.A.

    1994-01-01

    There are a variety of stressors that can affect the operation of centrifugal pumps. These can generally be classified as: Mechanical; Hydraulic; Tribological; Chemical; and Other (including those associated with the pump driver). Although these general stressors are active in essentially all centrifugal pumps, the stressor level and the extent of wear and degradation can vary greatly. Parameters that affect the extent of stressor activity are manifold. In order to assure the long-term operational readiness of a pump, it is important to both understand the nature and magnitude of the specific degradation mechanisms and to monitor the performance of the pump

  9. Influência do orvalho e volume de calda de aplicação na eficácia do glyphosate na dessecação de Brachiaria plantaginea Influence of dew and spray volume on the efficacy of glyphosate for Brachiaria plantaginea burndown

    Directory of Open Access Journals (Sweden)

    E.S. Roman

    2004-09-01

    Full Text Available A eficácia de herbicidas é influenciada por diversos fatores que afetam a absorção e a translocação desses compostos na planta. A absorção de herbicidas pelas plantas, por exemplo, é influenciada, tanto física como biologicamente, pela temperatura e pela umidade relativa do ar dentro do dossel. Com a diminuição da umidade relativa do ar e/ou com o aumento da temperatura, as gotas da pulverização secam mais rapidamente e a absorção do produto diminui, ou até mesmo cessa, afetando o desempenho biológico. Com base nessa premissa, o presente estudo teve como objetivo examinar a influência do orvalho e do volume de calda de aplicação na eficiência de doses de glyphosate para o controle de Brachiaria plantaginea. Foram observadas interações significativas entre volume de calda, orvalho e dose de glyphosate. O volume mais baixo (100 L ha-1 resultou em melhor controle da espécie, especialmente quando o herbicida foi usado na menor dose (90 g ha-1. A presença de orvalho nas folhas causou reduções na atividade do produto, especialmente quando aplicado na menor dose e combinado com maior volume de calda.The efficacy of herbicides is influenced by several factors affecting the absorption and translocation of these compounds in the plant. Herbicide plant absorption, for example, is both physically and biologically influenced by temperature and air relative humidity in the plant canopy. With the reduction in relative air humidity and/or increase in temperature, the spray droplets dry more rapidly and the absorption of the herbicide decreases or even stops, affecting the biological performance. Based on that, this research aimed to study the influence of dew and spray volume on the efficacy of glyphosate rates in the control of B. plantaginea. There were significant interactions among volume of water, dew and rate of glyphosate. The lower the water volume, the more effective the glyphosate activity was, especially when applied at

  10. 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])

  11. Bacterial Degradation of Pesticides

    DEFF Research Database (Denmark)

    Knudsen, Berith Elkær

    could potentially improve bioremediation of BAM. An important prerequisite for bioaugmentation is the potential to produce the degrader strain at large quantities within reasonable time. The aim of manuscript II, was to optimize the growth medium for Aminobacter MSH1 and to elucidate optimal growth...

  12. Radiation degradation of silk

    Energy Technology Data Exchange (ETDEWEB)

    Ishida, Kazushige; Kamiishi, Youichi [Textile Research Institute of Gunma, Kiryu, Gunma (Japan); Takeshita, Hidefumi; Yoshii, Fumio; Kume, Tamikazu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2001-03-01

    Silk fibroin powder was prepared from irradiated silk fibroin fiber by means of only physical treatment. Silk fibroin fiber irradiated with an accelerated electron beam in the dose range of 250 - 1000 kGy was pulverized by using a ball mill. Unirradiated silk fibroin fiber was not pulverized at all. But the more irradiation was increased, the more the conversion efficiency from fiber to powder was increased. The conversion efficiency of silk fibroin fiber irradiated 1000 kGy in oxygen was 94%. Silk fibroin powder shows remarkable solubility, which dissolved 57% into water of ambient temperature. It is a very interesting phenomenon that silk fibroin which did not treat with chemicals gets solubility only being pulverized. In order to study mechanism of solubilization of silk fibroin powder, amino acid component of soluble part of silk fibroin powder was analyzed. The more irradiation dose up, the more glycine or alanine degraded, but degradation fraction reached bounds about 50%. Other amino acids were degraded only 20% even at the maximum. To consider crystal construction of silk fibroin, it is suggested that irradiation on silk fibroin fiber selectively degrades glycine and alanine in amorphous region, which makes it possible to pulverize and to dissolve silk fibroin powder. (author)

  13. Detection of pump degradation

    International Nuclear Information System (INIS)

    Greene, R.H.; Casada, D.A.; Ayers, C.W.

    1995-08-01

    This Phase II Nuclear Plant Aging Research study examines the methods of detecting pump degradation that are currently employed in domestic and overseas nuclear facilities. This report evaluates the criteria mandated by required pump testing at U.S. nuclear power plants and compares them to those features characteristic of state-of-the-art diagnostic programs and practices currently implemented by other major industries. Since the working condition of the pump driver is crucial to pump operability, a brief review of new applications of motor diagnostics is provided that highlights recent developments in this technology. The routine collection and analysis of spectral data is superior to all other technologies in its ability to accurately detect numerous types and causes of pump degradation. Existing ASME Code testing criteria do not require the evaluation of pump vibration spectra but instead overall vibration amplitude. The mechanical information discernible from vibration amplitude analysis is limited, and several cases of pump failure were not detected in their early stages by vibration monitoring. Since spectral analysis can provide a wealth of pertinent information concerning the mechanical condition of rotating machinery, its incorporation into ASME testing criteria could merit a relaxation in the monthly-to-quarterly testing schedules that seek to verify and assure pump operability. Pump drivers are not included in the current battery of testing. Operational problems thought to be caused by pump degradation were found to be the result of motor degradation. Recent advances in nonintrusive monitoring techniques have made motor diagnostics a viable technology for assessing motor operability. Motor current/power analysis can detect rotor bar degradation and ascertain ranges of hydraulically unstable operation for a particular pump and motor set. The concept of using motor current or power fluctuations as an indicator of pump hydraulic load stability is presented

  14. Detection of pump degradation

    Energy Technology Data Exchange (ETDEWEB)

    Greene, R.H.; Casada, D.A.; Ayers, C.W. [and others

    1995-08-01

    This Phase II Nuclear Plant Aging Research study examines the methods of detecting pump degradation that are currently employed in domestic and overseas nuclear facilities. This report evaluates the criteria mandated by required pump testing at U.S. nuclear power plants and compares them to those features characteristic of state-of-the-art diagnostic programs and practices currently implemented by other major industries. Since the working condition of the pump driver is crucial to pump operability, a brief review of new applications of motor diagnostics is provided that highlights recent developments in this technology. The routine collection and analysis of spectral data is superior to all other technologies in its ability to accurately detect numerous types and causes of pump degradation. Existing ASME Code testing criteria do not require the evaluation of pump vibration spectra but instead overall vibration amplitude. The mechanical information discernible from vibration amplitude analysis is limited, and several cases of pump failure were not detected in their early stages by vibration monitoring. Since spectral analysis can provide a wealth of pertinent information concerning the mechanical condition of rotating machinery, its incorporation into ASME testing criteria could merit a relaxation in the monthly-to-quarterly testing schedules that seek to verify and assure pump operability. Pump drivers are not included in the current battery of testing. Operational problems thought to be caused by pump degradation were found to be the result of motor degradation. Recent advances in nonintrusive monitoring techniques have made motor diagnostics a viable technology for assessing motor operability. Motor current/power analysis can detect rotor bar degradation and ascertain ranges of hydraulically unstable operation for a particular pump and motor set. The concept of using motor current or power fluctuations as an indicator of pump hydraulic load stability is presented.

  15. 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% ...

  16. 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

    Directory of Open Access Journals (Sweden)

    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

  17. 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

    Directory of Open Access Journals (Sweden)

    Eurídice de Paula Pinheiro

    2007-09-01

    Full Text Available

    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

  18. 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

    Directory of Open Access Journals (Sweden)

    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

  19. 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.

    Directory of Open Access Journals (Sweden)

    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

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

    Directory of Open Access Journals (Sweden)

    Antônio Joaquim Braga Pereira Braz

    2007-09-01

    Full Text Available

    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 (

  1. 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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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

  3. TALSPEAK Solvent Degradation

    Energy Technology Data Exchange (ETDEWEB)

    Leigh R. Martin; Bruce J. Mincher

    2009-09-01

    Understanding the radiolytic degradation behavior of organic molecules involved in new or existing schemes for the recycle of used nuclear fuels is of significant interest for sustaining a closed nuclear fuel cycle. Here we have conducted several lines of investigation to begin understanding the effects of radiolysis on the aqueous phase of the TALSPEAK process for the separation of the trivalent lanthanides from the trivalent actinides. Using the 60-Co irradiator at the INL, we have begun to quantify the effects of radiation on the aqueous phase complexants used in this separation technique, and how this will affect the actinide lanthanide separation factor. In addition we have started to develop methodologies for stable product identification, a key element in determining the degradation pathways. We have also introduced a methodology to investigate the effects of alpha radiolysis that has previously received limited attention.

  4. Rapidly Degradable Pyrotechnic System

    Science.gov (United States)

    2009-02-01

    material system (structural polymer and degradation agent ) for producing a high strength, non-corroding, highly inert, environmentally safe, extended...polymer sites in the active enzyme center differs dramatically between alkyl and aromatic polyesters. More specifically, as the degree of backbone...capped and centrifuged at 3,000 g. This procedure was repeated twice. To the remaining biomass pellet 15 mL of 1 mg/mL solution of N-ethyl-N- nitrosourea

  5. Radiation degradation of chitosan

    International Nuclear Information System (INIS)

    Norzita Yacob; Maznah Mahmud; Norhashidah Talip; Kamarudin Bahari; Kamaruddin Hashim; Khairul Zaman Dahlan

    2010-01-01

    In order to obtain an oligo chitosan, degradation of chitosan s were carried out in solid state and liquid state. The effects of an irradiation on the molecular weight and viscosity of the chitosan were investigated using Ubbelohde Capillary Viscometer and Brookfield Viscometer respectively. The molecular weight and viscosity of the chitosan s were decreased with an increase in the irradiation dose. In the presence of hydrogen peroxide, the molecular weight of chitosan can be further decreased. (author)

  6. Detection of pump degradation

    International Nuclear Information System (INIS)

    Casada, D.

    1994-01-01

    There are a variety of stressors that can affect the operation of centrifugal pumps. Although these general stressors are active in essentially all centrifugal pumps, the stressor level and the extent of wear and degradation can vary greatly. Parameters that affect the extent of stressor activity are manifold. In order to assure the long-term operational readiness of a pump, it is important to both understand the nature and magnitude of the specific degradation mechanisms and to monitor the performance of the pump. The most commonly applied method of monitoring the condition of not only pumps, but rotating machinery in general, is vibration analysis. Periodic or continuous spectral vibration analysis is a cornerstone of most pump monitoring programs. In the nuclear industry, non-spectral vibration monitoring of safety-related pumps is performed in accordance with the ASME code. Although vibration analysis has dominated the condition monitoring field for many years, there are other measures that have been historically used to help understand pump condition: advances in historically applied technologies and developing technologies offer improved monitoring capabilities. The capabilities of several technologies (including vibration analysis, dynamic pressure analysis, and motor power analysis) to detect the presence and magnitude of both stressors and resultant degradation are discussed

  7. Detection of pump degradation

    International Nuclear Information System (INIS)

    Casada, D.

    1995-01-01

    There are a variety of stressors that can affect the operation of centrifugal pumps. Although these general stressors are active in essentially all centrifugal pumps, the stressor level and the extent of wear and degradation can vary greatly. Parameters that affect the extent of stressor activity are manifold. In order to assure the long-term operational readiness of a pump, it is important to both understand the nature and magnitude of the specific degradation mechanisms and to monitor the performance of the pump. The most commonly applied method of monitoring the condition of not only pumps, but rotating machinery in general, is vibration analysis. Periodic or continuous special vibration analysis is a cornerstone of most pump monitoring programs. In the nuclear industry, non-spectral vibration monitoring of safety-related pumps is performed in accordance with the ASME code. Pump head and flow rate are also monitored, per code requirements. Although vibration analysis has dominated the condition monitoring field for many years, there are other measures that have been historically used to help understand pump condition; advances in historically applied technologies and developing technologies offer improved monitoring capabilities. The capabilities of several technologies (including vibration analysis, dynamic pressure analysis, and motor power analysis) to detect the presence and magnitude of both stressors and resultant degradation are discussed

  8. WEATHERABILITY OF ENHANCED DEGRADABLE PLASTICS

    Science.gov (United States)

    The main objective of this study was to assess the performance and the asociated variability of several selected enhanced degradable plastic materials under a variety of different exposure conditions. Other objectives were to identify the major products formed during degradation ...

  9. 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.

  10. Radiation degradation of cellulose

    International Nuclear Information System (INIS)

    Leonhardt, J.; Arnold, G.; Baer, M.; Langguth, H.; Gey, M.; Huebert, S.

    1985-01-01

    The application of straw and other cellulose polymers as feedstuff for ruminants is limited by its low digestibility. During recent decades it was attempted to increase the digestibility of straw by several chemical and physical methods. In this work some results of the degradation of gamma and electron treated wheat straw are reported. Complex methods of treatment are taken into consideration. In vitro-experiments with radiation treated straw show that the digestibility can be increased from 20% up to about 80%. A high pressure liquid chromatography method was used to analyze the hydrolysates. The contents of certain species of carbohydrates in the hydrolysates in dependence on the applied dose are given. (author)

  11. Chemical degradation of pentachlorophenol

    International Nuclear Information System (INIS)

    Shukla, S.S.; Shukla, A.; Chandrasekharaiah, M.S.

    1992-01-01

    Industry produces a large volume of hazardous wastes containing pentachlorophenol, a U.S. EPA priority hazardous organic material. The environmentally safe disposal of these PCP-contaminated wastes is a serious problem for the waste management authorities as the current treatment processes are unsatisfactory. In this paper, the results of a feasibility study of chemical degradation and/or solidification methods for PCP-containing wastes. The photochemical decomposition of the PCP in a microemulsion or in micellar media obtained with the help of SDS or CTAB show the greatest promise

  12. Radiation degradation of polymethacrylamide

    International Nuclear Information System (INIS)

    O'Connor, D.J.

    1984-01-01

    The effects of radiation on polymers have been studied for many years. When polymers are subjected to ultraviolet light or ionizing radiation, chain scission and crosslinking are possible. The radiation degradations of several methacrylate type polymers were investigated. The primary polymer studied was polymethacrylamide (PMAAm). Ultraviolet irradiated PMAAm yielded a five line ESR spectrum with 22 gauss splitting which is believed to arise from a polymeric radical ending with a methacrylamide unit. The results obtained indicate that polymethacrylamide is a polymer which undergoes main chain cleavage upon irradiation. As such this polymer may have potential applicability as a positive resist for fabrication of microelectronic devices

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  15. Radiation degradation of cellulose

    International Nuclear Information System (INIS)

    Leonhardt, J.W.; Arnold, G.; Baer, M.; Gey, M.; Hubert, S.; Langguth, H.

    1984-01-01

    The application of straw and other cellulose polymers as feedstuff for ruminants is limited by its low digestibility. During recent decades it was attempted to increase the digestibility of straw by several chemical and physical methods. In this work some results of the degradation of gamma and electron treated wheat straw are reported. Complex methods of treatment (e.g. radiation influence and influence of lyes) are taken into consideration. In vitro-experiments with radiation treated straw show that the digestibility can be increased from 20% up to about 80%. A high pressure liquid chromatography method was used to analyze the hydrolysates. The contents of certain species of carbohydrates in the hydrolysates in dependence on the applied dose are given

  16. Exploring bacterial lignin degradation.

    Science.gov (United States)

    Brown, Margaret E; Chang, Michelle C Y

    2014-04-01

    Plant biomass represents a renewable carbon feedstock that could potentially be used to replace a significant level of petroleum-derived chemicals. One major challenge in its utilization is that the majority of this carbon is trapped in the recalcitrant structural polymers of the plant cell wall. Deconstruction of lignin is a key step in the processing of biomass to useful monomers but remains challenging. Microbial systems can provide molecular information on lignin depolymerization as they have evolved to break lignin down using metalloenzyme-dependent radical pathways. Both fungi and bacteria have been observed to metabolize lignin; however, their differential reactivity with this substrate indicates that they may utilize different chemical strategies for its breakdown. This review will discuss recent advances in studying bacterial lignin degradation as an approach to exploring greater diversity in the environment. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Soil degradation in Pakistan

    International Nuclear Information System (INIS)

    Khan, M.R.

    2005-01-01

    This paper diagnoses the issues involved behind the current state, usage, interactions and linkages in the soils in Pakistan. The condition of soils is deteriorating due to developmental and environmental factors such as soil degradation, water pollution, fauna degeneration etc. Issues, problems and constraints faced in the management and usage of soils are diagnosed at different levels in the ecosystems predominant in Pakistan. The research questions propose effective solutions, types of instruments, methods or processes to resolve the issues within the various areas or ecosystems in the most sustainable and effective manner [23]. Biological solutions and methods can be applied at the sub-system level by private individuals or communities at a lower cost, and at a more localized level than engineering methods. Engineering methods may be suited for interventions at a system level rather than at a sub-system level; but even at this level they will be complementary with biological methods. (author)

  18. Degraded Crater Rim

    Science.gov (United States)

    2002-01-01

    (Released 3 May 2002) The Science The eastern rim of this unnamed crater in Southern Arabia Terra is very degraded (beaten up). This indicates that this crater is very ancient and has been subjected to erosion and subsequent bombardment from other impactors such as asteroids and comets. One of these later (younger) craters is seen in the upper right of this image superimposed upon the older crater rim material. Note that this smaller younger crater rim is sharper and more intact than the older crater rim. This region is also mantled with a blanket of dust. This dust mantle causes the underlying topography to take on a more subdued appearance. The Story When you think of Arabia, you probably think of hot deserts and a lot of profitable oil reserves. On Mars, however, Southern Arabia Terra is a cold place of cratered terrain. This almost frothy-looking image is the badly battered edge of an ancient crater, which has suffered both erosion and bombardment from asteroids, comets, or other impacting bodies over the long course of its existence. A blanket of dust has also settled over the region, which gives the otherwise rugged landscape a soft and more subdued appearance. The small, round crater (upper left) seems almost gemlike in its setting against the larger crater ring. But this companionship is no easy romance. Whatever formed the small crater clearly whammed into the larger crater rim at some point, obliterating part of its edge. You can tell the small crater was formed after the first and more devastating impact, because it is laid over the other larger crater. How much younger is the small one? Well, its rim is also much sharper and more intact, which gives a sense that it is probably far more youthful than the very degraded, ancient crater.

  19. Ordered bulk degradation via autophagy

    DEFF Research Database (Denmark)

    Dengjel, Jörn; Kristensen, Anders Riis; Andersen, Jens S

    2008-01-01

    During amino acid starvation, cells undergo macroautophagy which is regarded as an unspecific bulk degradation process. Lately, more and more organelle-specific autophagy subtypes such as reticulophagy, mitophagy and ribophagy have been described and it could be shown, depending on the experimental...... at proteasomal and lysosomal degradation ample cross-talk between the two degradation pathways became evident. Degradation via autophagy appeared to be ordered and regulated at the protein complex/organelle level. This raises several important questions such as: can macroautophagy itself be specific and what...

  20. Degradation of thiram in soil

    International Nuclear Information System (INIS)

    Raghu, K.; Murthy, N.B.K.; Kumarsamy, R.

    1975-01-01

    Determination of the residual 35 S labelled tetramethylthiuram disulfide showed that the fungicide persisted longer in sterilized than in unsterilized soil, while the chloroform extractable radioactivity decreased, the water extractable radioactivity increased with increase in time. However, in sterilized soil the water extractable radioactivity remained more or less constant. Degradation of the fungicide was further demonstrated by the release of C 35 S 2 from soil treated with labelled thiram. Dimethylamine was found to be one of the degradation products. A bacterium isolated from thiram-enriched soil could degrade the fungicide in shake culture. The degradation pathways of thiram in sterilized and unsterilized soils are discussed. (author)

  1. In vitro degradation of ribosomes.

    Science.gov (United States)

    Mora, G; Rivas, A

    1976-12-01

    The cytoplasmic ribosomes from Euglena gracilis var. bacillaris are found to be of two types taking into consideration their stability "in vitro". In the group of unstable ribosomes the large subunit is degraded. The other group apparently does not suffer any degradation under the conditions described. However the RNAs extracted from both types of ribosomes are degraded during sucrose density gradients. The degradation of the largest RNA species has been reported previously, but no comment has been made about the stability of the ribosome itself.

  2. The radiation degradation of polypropylene

    International Nuclear Information System (INIS)

    De Hollain, G.

    1977-04-01

    Polypropylene is used extensively in the manufacture of disposable medical devices because of its superior properties. Unfortunately this polymer does not lend itself well to radiation sterilization, undergoing serious degradation which affects the mechanical properties of the polymer. In this paper the effects of radiation on the mechanical and physical properties of polypropylene are discussed. A programme of research to minimize the radiation degradation of this polymer through the addition of crosslinking agents to counteract the radiation degradation is proposed. It is furthermore proposed that a process of annealing of the irradiated polymer be investigated in order to minimize the post-irradiation degradation of the polypropylene [af

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

    Directory of Open Access Journals (Sweden)

    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

  4. Polycarbonate radiolytic degradation and stabilization

    International Nuclear Information System (INIS)

    Araujo, E.S. de

    1994-01-01

    Polycarbonate Durolon, useful for medical supplies fabrication, is submitted to gamma radiation for sterilization purposes. Scissions in main chain occur, in carbonyl groups, producing molecular degradations and yellowness. The radiolytic stabilization is obtained through additive to the polymer. In this work some degradation and stabilization aspects are presented. (L.C.J.A.). 7 refs, 7 figs, 2 tabs

  5. Degradation of copepod fecal pellets

    DEFF Research Database (Denmark)

    Poulsen, Louise K.; Iversen, Morten

    2008-01-01

    amount of fecal pellets. The total degradation rate of pellets by the natural plankton community of Oresund followed the phytoplankton biomass, with maximum degradation rate during the spring bloom (2.5 +/- 0.49 d(-1)) and minimum (0.52 +/- 0.14 d(-1)) during late winter. Total pellet removal rate ranged...

  6. Degradable polymers for tissue engineering

    NARCIS (Netherlands)

    van Dijkhuizen-Radersma, Riemke; Moroni, Lorenzo; van Apeldoorn, Aart A.; Zhang, Zheng; Grijpma, Dirk W.; van Blitterswijk, Clemens A.

    2008-01-01

    This chapter elaborates the degradable polymers for tissue engineering and their required scaffold material in tissue engineering. It recognizes the examples of degradable polymers broadly used in tissue engineering. Tissue engineering is the persuasion of the body to heal itself through the

  7. MOSFET Degradation Under RF Stress

    NARCIS (Netherlands)

    Sasse, G.T.; Kuper, F.G.; Schmitz, Jurriaan

    2008-01-01

    We report on the degradation of MOS transistors under RF stress. Hot-carrier degradation, negative-bias temperature instability, and gate dielectric breakdown are investigated. The findings are compared to established voltage- and field-driven models. The experimental results indicate that the

  8. Designs for degraded Trbovlje

    Directory of Open Access Journals (Sweden)

    Naja Marot

    2005-01-01

    Full Text Available As an introduction, two degraded urban areas are presented. The first, planning unit seven, is situated in the southeastern part of Trbovlje town. The other, called Speke, lies to the south of Liverpool. The basis for the concept and context of urban renewal model are given by comparison between the newest Slovene and British spatial planning legislation, analyses of the Design management plan Nasipi and Supplementary Planning Document Edge Lane West, and review of different approaches to local communities’ involvement. Based on all the thus far collected data, a questionnaire about quality of living, knowledge of planning system and area perception was produced. Initially, it was used in a pilot residential area Žabjek, and afterwards, a shortened version was carried out in units lying in other parts of the town. Other stakeholders also expressed their ideas about how to develop planning unit seven. Speke Garston as another example of successful urban renewal is given. In conclusion guidelines for method and context development of urban renewal are given for planning unit seven, with emphasis on the Žabjek estate.

  9. Lysosomal degradation of membrane lipids.

    Science.gov (United States)

    Kolter, Thomas; Sandhoff, Konrad

    2010-05-03

    The constitutive degradation of membrane components takes place in the acidic compartments of a cell, the endosomes and lysosomes. Sites of lipid degradation are intralysosomal membranes that are formed in endosomes, where the lipid composition is adjusted for degradation. Cholesterol is sorted out of the inner membranes, their content in bis(monoacylglycero)phosphate increases, and, most likely, sphingomyelin is degraded to ceramide. Together with endosomal and lysosomal lipid-binding proteins, the Niemann-Pick disease, type C2-protein, the GM2-activator, and the saposins sap-A, -B, -C, and -D, a suitable membrane lipid composition is required for degradation of complex lipids by hydrolytic enzymes. Copyright 2009 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  10. Nitrogen fertilization efficiency with Urea (15N) in Brachiaria brizantha cv. Marandu associated with split application of ordinary superphosphate and potassium chloride

    International Nuclear Information System (INIS)

    Oliveira, P.P.A.; Trivelin, P.C.O.; Oliveira, W.S.

    2003-01-01

    In pastures, the evaluation of fertilization efficiency of urea-N is important since it is applied on a massive scale. Several studies report an enhancement of the fertilizers efficiency by associated applications of urea with potassium chloride (KCl) and ordinary superphosphate (OSP). In the recovery of degraded pastures or in intensive exploration systems, high quantities of KCl and OSP used as corrective fertilization are applied at the november, beginning of the rain season. Split applications of KCl and OSP could easily be associated with urea-N surface application without additional costs. An evaluation of this management was the objective of this experiment. The annual balance of 15 N application with urea was obtained in treatments where OSP and/or KCl were split, top-dressed in five applications associated with urea, or when both were applied together in November. Highest forage production was obtained when OSP was split, followed by split KCl, the unique application of both together, and finally both split. The recovery of urea-N in the aerial part and the soil-pasture system remained unaltered by the treatments. However, the recovery of plant crown and root system differed among the treatments and was positively correlated with forage production. Fertilizer-N recovery in the litter was favored by splitting KCl. Even though the total recovery of the system was not improved by the treatments, splitting of KCl and OSP are indicated for an increased recovery of urea-N in numerous plant structures, resulting in a higher forage production. (author)

  11. 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

    Directory of Open Access Journals (Sweden)

    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

  12. Drift Degradation Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Dwayne C. Kicker

    2001-09-28

    A statistical description of the probable block sizes formed by fractures around the emplacement drifts has been developed for each of the lithologic units of the repository host horizon. A range of drift orientations with the drift azimuth varied in 15{sup o} increments has been considered in the static analysis. For the quasi-static seismic analysis, and the time-dependent and thermal effects analysis, two drift orientations have been considered: a drift azimuth of 105{sup o} and the current emplacement drift azimuth of 75{sup o}. The change in drift profile resulting from progressive deterioration of the emplacement drifts has been assessed both with and without backfill. Drift profiles have been determined for four different time increments, including static (i.e., upon excavation), 200 years, 2,000 years, and 10,000 years. The effect of seismic events on rock fall has been analyzed. Block size distributions and drift profiles have been determined for three seismic levels, including a 1,000-year event, a 5,000-year event, and a 10,000-year event. Data developed in this modeling and analysis activity have been entered into the TDMS (DTN: MO0109RDDAAMRR.003). The following conclusions have resulted from this drift degradation analysis: (1) The available fracture data are suitable for supporting a detailed key block analysis of the repository host horizon rock mass. The available data from the north-south Main Drift and the east-west Cross Drift provide a sufficient representative fracture sample of the repository emplacement drift horizon. However, the Tptpln fracture data are only available from a relatively small section of the Cross Drift, resulting in a smaller fracture sample size compared to the other lithologic units. This results in a lower degree of confidence that the key block data based on the Tptpln data set is actually representative of the overall Tptpln key block population. (2) The seismic effect on the rock fall size distribution for all events

  13. 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

    Directory of Open Access Journals (Sweden)

    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

  14. Intrinsic immunogenicity of rapidly-degradable polymers evolves during degradation.

    Science.gov (United States)

    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

  15. Operationalizing measurement of forest degradation

    DEFF Research Database (Denmark)

    Dons, Klaus; Smith-Hall, Carsten; Meilby, Henrik

    2015-01-01

    . In Tanzania, charcoal production is considered a major cause of forest degradation, but is challenging to quantify due to sub-canopy biomass loss, remote production sites and illegal trade. We studied two charcoal production sites in dry Miombo woodland representing open woodland conditions near human......Quantification of forest degradation in monitoring and reporting as well as in historic baselines is among the most challenging tasks in national REDD+ strategies. However, a recently introduced option is to base monitoring systems on subnational conditions such as prevalent degradation activities...

  16. Ecosystemic approaches to land degradation

    Energy Technology Data Exchange (ETDEWEB)

    Puigdefabregas, J.; Barrio, G. del; Hill, J.

    2009-07-01

    Land degradation is recognized as the main outcome of desertification. However available procedures for its assessment are still unsatisfactory because are often too costly for surveying large areas and rely on specific components of the degradation process without being able to integrate them in a unique process. One of the objectives of De Survey project is designing and implementing operational procedures for desertification surveillance, including land degradation. A strategic report was compiled and reproduced here for selecting the most appropriate approaches to the project conditions. The report focuses on using attributes of ecosystem maturity as a natural way to integrate the different drivers of land degradation in simple indices. The review surveys different families of attributes concerned with water and energy fluxes through the ecosystem, its capacity to sustain biomass and net primary productivity, and its capacity to structure the space. Finally, some conclusions are presented about the choice criteria of the different approaches in the framne of operational applications. (Author) 20 refs.

  17. Ecosystemic approaches to land degradation

    International Nuclear Information System (INIS)

    Puigdefabregas, J.; Barrio, G. del; Hill, J.

    2009-01-01

    Land degradation is recognized as the main outcome of desertification. However available procedures for its assessment are still unsatisfactory because are often too costly for surveying large areas and rely on specific components of the degradation process without being able to integrate them in a unique process. One of the objectives of De Survey project is designing and implementing operational procedures for desertification surveillance, including land degradation. A strategic report was compiled and reproduced here for selecting the most appropriate approaches to the project conditions. The report focuses on using attributes of ecosystem maturity as a natural way to integrate the different drivers of land degradation in simple indices. The review surveys different families of attributes concerned with water and energy fluxes through the ecosystem, its capacity to sustain biomass and net primary productivity, and its capacity to structure the space. Finally, some conclusions are presented about the choice criteria of the different approaches in the framne of operational applications. (Author) 20 refs.

  18. Chitin Degradation In Marine Bacteria

    DEFF Research Database (Denmark)

    Paulsen, Sara; Machado, Henrique; Gram, Lone

    2015-01-01

    Introduction: Chitin is the most abundant polymer in the marine environment and the second most abundant in nature. Chitin does not accumulate on the ocean floor, because of microbial breakdown. Chitin degrading bacteria could have potential in the utilization of chitin as a renewable carbon...... and nitrogen source in the fermentation industry.Methods: Here, whole genome sequenced marine bacteria were screened for chitin degradation using phenotypic and in silico analyses.Results: The in silico analyses revealed the presence of three to nine chitinases in each strain, however the number of chitinases...... chitin regulatory system.Conclusions: This study has provided insight into the ecology of chitin degradation in marine bacteria. It also served as a basis for choosing a more efficient chitin degrading production strain e.g. for the use of chitin waste for large-scale fermentations....

  19. Predicting degradability of organic chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Finizio, A; Vighi, M [Milan Univ. (Italy). Ist. di Entomologia Agraria

    1992-05-01

    Degradability, particularly biodegradability, is one of the most important factors governing the persistence of pollutants in the environment and consequently influencing their behavior and toxicity in aquatic and terrestrial ecosystems. The need for reliable persistence data in order to assess the environmental fate and hazard of chemicals by means of predictive approaches, is evident. Biodegradability tests are requested by the EEC directive on new chemicals. Neverthless, degradation tests are not easy to carry out and data on existing chemicals are very scarce. Therefore, assessing the fate of chemicals in the environment from the simple study of their structure would be a useful tool. Rates of degradation are a function of the rates of a series of processes. Correlation between degradation rates and structural parameters are will be facilitated if one of the processes is rate determining. This review is a survey of studies dealing with relationships between structure and biodegradation of organic chemicals, to identify the value and limitations of this approach.

  20. 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

    Directory of Open Access Journals (Sweden)

    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

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

    Science.gov (United States)

    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

  2. Working session 1: Tubing degradation

    International Nuclear Information System (INIS)

    Kharshafdjian, G.; Turluer, G.

    1997-01-01

    A general introductory overview of the purpose of the group and the general subject area of SG tubing degradation was given by the facilitator. The purpose of the session was described as to open-quotes develop conclusions and proposals on regulatory and technical needs required to deal with the issues of SG tubing degradation.close quotes Types, locations and characteristics of tubing degradation in steam generators were briefly reviewed. The well-known synergistic effects of materials, environment, and stress and strain/strain rate, subsequently referred to by the acronym open-quotes MESSclose quotes by some of the group members, were noted. The element of time (i.e., evolution of these variables with time) was emphasized. It was also suggested that the group might want to consider the related topics of inspection capabilities, operational variables, degradation remedies, and validity of test data, and some background information in these areas was provided. The presentation given by Peter Millet during the Plenary Session was reviewed; Specifically, the chemical aspects and the degradation from the secondary side of the steam generator were noted. The main issues discussed during the October 1995 EPRI meeting on secondary side corrosion were reported, and a listing of the potential SG tube degradations was provided and discussed

  3. Abiotic degradation of plastic films

    Science.gov (United States)

    Ángeles-López, Y. G.; Gutiérrez-Mayen, A. M.; Velasco-Pérez, M.; Beltrán-Villavicencio, M.; Vázquez-Morillas, A.; Cano-Blanco, M.

    2017-01-01

    Degradable plastics have been promoted as an option to mitigate the environmental impacts of plastic waste. However, there is no certainty about its degradability under different environmental conditions. The effect of accelerated weathering (AW), natural weathering (NW) and thermal oxidation (TO) on different plastics (high density polyethylene, HDPE; oxodegradable high density polyethylene, HDPE-oxo; compostable plastic, Ecovio ® metalized polypropylene, PP; and oxodegradable metalized polypropylene, PP-oxo) was studied. Plastics films were exposed to AW per 110 hours; to NW per 90 days; and to TO per 30 days. Plastic films exposed to AW and NW showed a general loss on mechanical properties. The highest reduction in elongation at break on AW occurred to HDPE-oxo (from 400.4% to 20.9%) and was higher than 90% for HDPE, HDPE-oxo, Ecovio ® and PP-oxo in NW. No substantial evidence of degradation was found on plastics exposed to TO. Oxo-plastics showed higher degradation rates than their conventional counterparts, and the compostable plastic was resistant to degradation in the studied abiotic conditions. This study shows that degradation of plastics in real life conditions will vary depending in both, their composition and the environment.

  4. Producción de forraje y composición morfológica del pasto Mulato (Brachiaria híbrido 36061 sometido a diferentes regímenes de pastoreo

    Directory of Open Access Journals (Sweden)

    Aldenamar Cruz Hernández

    2011-01-01

    Full Text Available En Brachiaria híbrido se estudiaron tres frecuencias (14, 21 y 28 días y dos intensidades de pastoreo (9-11 y 13-15 cm, distribuidos en un diseño de bloques al azar en arreglo factorial 3 x 2 con tres repeticiones. Se midió, acumulación de forraje, tasa de crecimiento (TC composición botánica y relación hoja, tallo. No hubo efecto de int eracción (P>0.05 frecuencia x intensidad en la acumulación de forraje. La distribución del rendimiento fue de 55, 28 y 17 % durante las épocas de lluvias, nortes y seca, en el año 2007-2008, con la mayor acumulación anual (12,310 kg MS ha-1 al pastorear cada 28 días, con un incremento progresivo conforme aumentó el intervalo de pastoreo de 14 a 28 días (P<0.05. Similar comportamiento se observó para el periodo 2008-2009, la mayor TC se obtuvo en la época de lluvias con 36, 44, 47 kg MS ha-1 d-1, a frecuencias de 14, 21 y 28 días. La menor TC se presentó en la época seca. En la composición morfológica la mayor acumulación de hoja se presentó en la época de lluvias, seguido por las épocas de nortes y seca cada 28 días, a intensidad de 13-15 cm. En conclusión, la mayor producción de forraje, tasa de crecimiento, composición morfológica y relación hoja, tallo se concentró en la época de lluvias con intensidad de pastoreo de 13-15 cm cada 21 y 28 días.

  5. Degradation of shape memory effect

    International Nuclear Information System (INIS)

    Vandermeer, R.A.

    1983-01-01

    An important parameter for deciding whether or not a SME alloy is suitable for practical applications is the magnitude of the strain reversal accompanying martensite reversion. This research is concerned with elucidating metallurgical factors that cause degradation of this heat-activated recovery strain, E/sub R/. After explaining what is meant by degradation, two manifestations of degradation recently identified in near-monotectoid uranium-niobium alloys are described. The first was associated with the onset of plastic deformation of the martensite beyond the reversible strain limit, E/sub L/; a reduction of E/sub R/ from 5.25% at 8% total strain, i.e. E/sub L/, to 2.9% at 12% total strain was observed. A second type of degradation depended strongly on the heating rate during reversion; the E/sub R/ for an imposed strain of 6.95% was reduced from a value of 5.25% to 1.3% when the heating rate was decreased from 40 0 /sec to 0.05 0 /sec. Degradation was attributed to a change in the transformation path and the interjection of time-dependent, low temperature aging reactions

  6. Clad Degradation - FEPs Screening Arguments

    International Nuclear Information System (INIS)

    E. Siegmann

    2004-01-01

    The purpose of this report is to document the screening of the cladding degradation features, events, and processes (FEPs) for commercial spent nuclear fuel (CSNF). This report also addresses the effect of some FEPs on both the cladding and the CSNF, DSNF, and HLW waste forms where it was considered appropriate to address the effects on both materials together. This report summarizes the work of others to screen clad degradation FEPs in a manner consistent with, and used in, the Total System Performance Assessment-License Application (TSPA-LA). This document was prepared according to ''Technical Work Plan for Waste Form Degradation Modeling, Testing, and Analyses in Support of LA'' (BSC 2004a [DIRS 167796])

  7. Radiation degradation of silk protein

    International Nuclear Information System (INIS)

    Pewlong, W.; Sudatis, B.; Takeshita, Hidefumi; Yoshii, Fumio; Kume, Tamikazu

    2000-01-01

    Silk fibroin fiber from the domesticated silkworm Bombyx mori was irradiated using an electron beam accelerator to investigate the application of the radiation degradation technique as a means to solubilize fibroin. The irradiation caused a significant degradation of the fiber. The tensile strength of fibroin fiber irradiated up to 2500 kGy decreased rapidly with increasing dose. The presence of oxygen in the irradiation atmosphere enhanced degradation of the tensile strength. The solubilization of irradiated fibroin fiber was evaluated using the following three kinds of solutions: a calcium chloride solution(CaCl 2 /C 2 H 5 OH/H 2 O=1:2:8 in mole ratio), a hydrochloric acid (0.5 N) and a distilled water. Dissolution of fibroin fiber into these solutions was significantly enhanced by irradiation. Especially, an appreciable amount of water soluble proteins was extracted by a distilled water. (author)

  8. Radiation degradation of silk protein

    Energy Technology Data Exchange (ETDEWEB)

    Pewlong, W; Sudatis, B [Office of Atomic Energy for Peace, Bangkok (Thailand); Takeshita, Hidefumi; Yoshii, Fumio; Kume, Tamikazu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2000-03-01

    Silk fibroin fiber from the domesticated silkworm Bombyx mori was irradiated using an electron beam accelerator to investigate the application of the radiation degradation technique as a means to solubilize fibroin. The irradiation caused a significant degradation of the fiber. The tensile strength of fibroin fiber irradiated up to 2500 kGy decreased rapidly with increasing dose. The presence of oxygen in the irradiation atmosphere enhanced degradation of the tensile strength. The solubilization of irradiated fibroin fiber was evaluated using the following three kinds of solutions: a calcium chloride solution(CaCl{sub 2}/C{sub 2}H{sub 5}OH/H{sub 2}O=1:2:8 in mole ratio), a hydrochloric acid (0.5 N) and a distilled water. Dissolution of fibroin fiber into these solutions was significantly enhanced by irradiation. Especially, an appreciable amount of water soluble proteins was extracted by a distilled water. (author)

  9. The Science of Battery Degradation

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, John P. [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Materials Physics; El Gabaly Marquez, Farid [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Materials Physics; McCarty, Kevin [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Materials Physics; Sugar, Joshua Daniel [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Materials Physics; Talin, Alec A. [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Materials Physics; Fenton, Kyle R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Power Sources Design and Development; Nagasubramanian, Ganesan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Power Sources Design and Development; Harris, Charles Thomas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Nanosystems Synthesis/Analysis; Jungjohann, Katherine Leigh [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Nanosystems Synthesis/Analysis; Hayden, Carl C. [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Combustion Chemistry Dept.; Kliewer, Christopher Jesse [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Combustion Chemistry Dept.; Hudak, Nicholas S. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Power Sources Research and Development; Leung, Kevin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Nanostructure Physics; McDaniel, Anthony H. [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Hydrogen and Combustion Technology; Tenney, Craig M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Chemical and Biological Systems; Zavadil, Kevin R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Advanced Materials Lab.

    2015-01-01

    This report documents work that was performed under the Laboratory Directed Research and Development project, Science of Battery Degradation. The focus of this work was on the creation of new experimental and theoretical approaches to understand atomistic mechanisms of degradation in battery electrodes that result in loss of electrical energy storage capacity. Several unique approaches were developed during the course of the project, including the invention of a technique based on ultramicrotoming to cross-section commercial scale battery electrodes, the demonstration of scanning transmission x-ray microscopy (STXM) to probe lithium transport mechanisms within Li-ion battery electrodes, the creation of in-situ liquid cells to observe electrochemical reactions in real-time using both transmission electron microscopy (TEM) and STXM, the creation of an in-situ optical cell utilizing Raman spectroscopy and the application of the cell for analyzing redox flow batteries, the invention of an approach for performing ab initio simulation of electrochemical reactions under potential control and its application for the study of electrolyte degradation, and the development of an electrochemical entropy technique combined with x-ray based structural measurements for understanding origins of battery degradation. These approaches led to a number of scientific discoveries. Using STXM we learned that lithium iron phosphate battery cathodes display unexpected behavior during lithiation wherein lithium transport is controlled by nucleation of a lithiated phase, leading to high heterogeneity in lithium content at each particle and a surprising invariance of local current density with the overall electrode charging current. We discovered using in-situ transmission electron microscopy that there is a size limit to lithiation of silicon anode particles above which particle fracture controls electrode degradation. From electrochemical entropy measurements, we discovered that entropy

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

    Directory of Open Access Journals (Sweden)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  12. Degradation of materials and passivity

    International Nuclear Information System (INIS)

    Meisel, W.

    1997-01-01

    Demanding for a reduction in materials degradation is a serious problem all over the world. Moessbauer spectroscopy (MS) is, among others, a very valuable tool to follow many degradation processes. Evidently, Fe is the most important Moessbauer element considering the overall presence of iron in everyday life. MS may contribute to our knowledge about nearly all fields of materials degradation, chemical, mechanical, thermal, irradiative, etc. Following some general lines, corrosion is considered in particular. MS is applicable to investigate the bulk of materials as well as their surface layers with an information depth of ca. 250 nm. In general, it has to be applied as a surface sensitive method in combination with other relevant methods in order to get a detailed insight into ongoing processes. Some examples have been selected to elucidate the application of MS in this field. Another class of examples concerns attempts to prevent corrosion, i.e., the application of coatings and transforming chemicals. A very effective and most natural way to reduce corrosion is the passivation of materials. The effect of passive layers and their destruction by environmental influences are discussed using results of MS and related methods. It is outlined that passivity is not restricted to chemically treated metals but can be considered as a general concept for preventing different kinds of materials from degradation. (orig.)

  13. Land degradation and property regimes

    Science.gov (United States)

    Paul M. Beaumont; Robert T. Walker

    1996-01-01

    This paper addresses the relationship between property regimes and land degradation outcomes, in the context of peasant agriculture. We consider explicitly whether private property provides for superior soil resource conservation, as compared to common property and open access. To assess this we implement optimization algorithms on a supercomputer to address resource...

  14. Degradation of CIGS solar cells

    NARCIS (Netherlands)

    Theelen, M.J.

    2015-01-01

    Large scale commercial introduction of CIGS photovoltaics (PV) requires modules with low costs, high efficiencies and long and predictable lifetimes. Unfortunately,knowledge about the lifetime of CIGS PV is limited, which is reflected in the results of field studies: degradation rates varying from

  15. The Degradation of a Nation.

    Science.gov (United States)

    Morozova, Galina Fedorouna

    1995-01-01

    Maintains that the process of national degradation is a real danger and concern of all Russian society. Discusses environmental concerns, such as water, soil, and air pollution; falling birth rates; aging of the population; crime; and decline in moral values. Concludes that it is imperative for all citizens to stop and reverse these trends. (CFR)

  16. Polymeric Materials - introduction and degradation

    DEFF Research Database (Denmark)

    Kontogeorgis, Georgios

    1999-01-01

    These notes support the polymer part of the courses 91742 and 91762 (Materials and Corrosion/degradation of materials) taught in IFAKthey contain a short introduction on group contribution methods for estimating properties of polymers, polymer thermodynamics, viscoelasticity models as well...

  17. Abiotic degradation of antibiotic ionophores

    DEFF Research Database (Denmark)

    Bohn, Pernille; Bak, Søren A; Björklund, Erland

    2013-01-01

    Hydrolytic and photolytic degradation were investigated for the ionophore antibiotics lasalocid, monensin, salinomycin, and narasin. The hydrolysis study was carried out by dissolving the ionophores in solutions of pH 4, 7, and 9, followed by incubation at three temperatures of 6, 22, and 28 °C f...... because they absorb light of environmentally irrelevant wavelengths....

  18. Nitrogen fertilization efficiency with Urea ({sup 15}N) in Brachiaria brizantha cv. Marandu associated with split application of ordinary superphosphate and potassium chloride; Eficiencia da fertilizacao nitrogenada com ureia ({sup 15}N) em Brachiaria brizantha cv. Marandu associada ao parcelamento de superfosfato simples e cloreto de potassio

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, P.P.A. [EMBRAPA, Pirassununga, SP (Brazil). Centro Nacional de Pesquisa de Gado e Leite]. E-mail: ppaolive@cnpgl.embrapa.br; Trivelin, P.C.O. [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Lab. de Isotopos Estaveis]. E-mail: pcotrive@cena.usp.br; Oliveira, W.S. [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Lab. de Biologia Celular e Molecular]. E-mail: wsolivei@carpa.ciagri.usp.br

    2003-08-01

    In pastures, the evaluation of fertilization efficiency of urea-N is important since it is applied on a massive scale. Several studies report an enhancement of the fertilizers efficiency by associated applications of urea with potassium chloride (KCl) and ordinary superphosphate (OSP). In the recovery of degraded pastures or in intensive exploration systems, high quantities of KCl and OSP used as corrective fertilization are applied at the november, beginning of the rain season. Split applications of KCl and OSP could easily be associated with urea-N surface application without additional costs. An evaluation of this management was the objective of this experiment. The annual balance of {sup 15} N application with urea was obtained in treatments where OSP and/or KCl were split, top-dressed in five applications associated with urea, or when both were applied together in November. Highest forage production was obtained when OSP was split, followed by split KCl, the unique application of both together, and finally both split. The recovery of urea-N in the aerial part and the soil-pasture system remained unaltered by the treatments. However, the recovery of plant crown and root system differed among the treatments and was positively correlated with forage production. Fertilizer-N recovery in the litter was favored by splitting KCl. Even though the total recovery of the system was not improved by the treatments, splitting of KCl and OSP are indicated for an increased recovery of urea-N in numerous plant structures, resulting in a higher forage production. (author)

  19. Desynapsis and precocious cytokinesis in Brachiaria humidicola ...

    Indian Academy of Sciences (India)

    and infertile acid soils, it has achieved wide utilization for pastures in Brazilian farms. Among the 55 ... In higher plants, cytokinesis is a genetically controlled multistep ... systems owing to its good adaptation to poorly drained and infertile acid ...

  20. Desynapsis and precocious cytokinesis in Brachiaria humidicola ...

    Indian Academy of Sciences (India)

    Among the 55 accessions of B. humidicola analysed from the Embrapa Beef Cattle collection, one (H022), presented desynapsis and an abnormal pattern of cytokinesis in the first meiotic division. Among 28 inflorescences analysed in this accession, 12 were affected by the anomaly. In affected meiocytes, the first ...

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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:

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

    OpenAIRE

    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 ...

  4. Advanced Oxidation Degradation of Diclofenac

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, William J., E-mail: wcooper@uci.edu [Urban Water Research Center, Department of Civil and Environmental Engineering, University of California, Irvine, CA 92697 (United States); Song Weihua, E-mail: wsong@fudan.edu.cn [Department of Environmental Science & Engineering, Fudan University, Shanghai 200433 (China)

    2012-07-01

    Advanced oxidation/reduction processes (AO/RPs), utilize free radical reactions to directly degrade chemical contaminants as an alternative to traditional water treatment. This study reports the absolute rate constants for reaction of diclofenac sodium and the model compound (2, 6-dichloraniline) with the two major AO/RP radicals; the hydroxyl radical (•OH) and hydrated electron (e{sup -}{sub aq}). The bimolecular reaction rate constants (M{sup -1} s{sup -1}) for diclofenac for •OH was (9.29 ± 0.11) x 10{sup 9}, and, for e- aq was (1.53 ± 0.03) x10{sup 9}. Preliminary degradation mechanisms are suggested based on product analysis using {sup 60}Co γ-irradiation and LC-MS for reaction by-product identification. The toxicity of products was evaluated using the Vibrio fischeri luminescent bacteria method. (author)

  5. Advanced Oxidation Degradation of Diclofenac

    International Nuclear Information System (INIS)

    Cooper, William J.; Song Weihua

    2012-01-01

    Advanced oxidation/reduction processes (AO/RPs), utilize free radical reactions to directly degrade chemical contaminants as an alternative to traditional water treatment. This study reports the absolute rate constants for reaction of diclofenac sodium and the model compound (2, 6-dichloraniline) with the two major AO/RP radicals; the hydroxyl radical (•OH) and hydrated electron (e - aq ). The bimolecular reaction rate constants (M -1 s -1 ) for diclofenac for •OH was (9.29 ± 0.11) x 10 9 , and, for e- aq was (1.53 ± 0.03) x10 9 . Preliminary degradation mechanisms are suggested based on product analysis using 60 Co γ-irradiation and LC-MS for reaction by-product identification. The toxicity of products was evaluated using the Vibrio fischeri luminescent bacteria method. (author)

  6. Fungal degradation of organophosphorous insecticides

    Energy Technology Data Exchange (ETDEWEB)

    Bumpus, J.A. [Notre Dame Univ., IN (United States); Kakar, S.N.; Coleman, R.D. [Argonne National Lab., IL (United States)

    1992-07-01

    Organophosphorous insecticides are used extensively to treat a variety of pests and insects. Although as a group they are easily degraded by bacteria in the environment, a number of them have half-lives of several months. Little is known about their biodegradation by fungi. We have shown that Phanerochaete chrysosporium can substantially degrade chlorpyrifos, fonofos, and terbufos (27.5%, 12.2%, and 26.6%, respectively) during 18-day incubation in nitrogen-limited stationary cultures. The results demonstrate that the clorinated pyridinyl ring of chlorpyrifos and the phenyl ring of fonofos undergo ring cleavage during biodegradation by the fungus. The usefulness of the fungus system for bioremediation is discussed. 16 refs., 7 figs., 2 tabs.

  7. Fungal degradation of organophosphorous insecticides

    Energy Technology Data Exchange (ETDEWEB)

    Bumpus, J.A. (Notre Dame Univ., IN (United States)); Kakar, S.N.; Coleman, R.D. (Argonne National Lab., IL (United States))

    1992-01-01

    Organophosphorous insecticides are used extensively to treat a variety of pests and insects. Although as a group they are easily degraded by bacteria in the environment, a number of them have half-lives of several months. Little is known about their biodegradation by fungi. We have shown that Phanerochaete chrysosporium can substantially degrade chlorpyrifos, fonofos, and terbufos (27.5%, 12.2%, and 26.6%, respectively) during 18-day incubation in nitrogen-limited stationary cultures. The results demonstrate that the clorinated pyridinyl ring of chlorpyrifos and the phenyl ring of fonofos undergo ring cleavage during biodegradation by the fungus. The usefulness of the fungus system for bioremediation is discussed. 16 refs., 7 figs., 2 tabs.

  8. Radiation degradation of silk protein

    Energy Technology Data Exchange (ETDEWEB)

    Wachiraporn Pewlong; Boonya Sudatis [Office of Atomic Energy for Peace, Bangkok (Thailand); Takeshita, Hidefumi; Yoshii, Fumio; Kume, Tamikazu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2000-09-01

    Silk fibroin fiber from the domesticated silkworm Bombyx mori was irradiated in the dose range up to 2500 kGy using an electron beam accelerator to apply the radiation degradation technique as a means to solubilize fibroin. The tensile strength of irradiated fibroin fiber decreased with increasing dose and the presence of oxygen in the irradiation atmosphere enhanced the degradation. The solubilization of irradiated fibroin fiber was evaluated using the following three kinds of solutions: calcium chloride solution (CaCl{sub 2}/C{sub 2}H{sub 5}OH/H{sub 2}O = 1 : 2 : 8 in mole ratio), hydrochloric acid (0.5N) and distilled water. Dissolution of fibroin fiber into these solutions was significantly enhanced by irradiation. Especially, an appreciable amount of water-soluble protein was extracted by distilled water. (author)

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

    Directory of Open Access Journals (Sweden)

    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

  10. Degradation and inhibition of cyclooxygenase

    OpenAIRE

    Neuß, Heiko

    2011-01-01

    The cyclooxygenase (COX) is a central enzyme in the genesis of pain, inflammation and carcinogenesis. Two major isoforms, COX-1 and COX-2, have been described. The COX-1 is constitutively expressed in most tissues and has housekeeping functions, whereas the COX-2 is the inducible isoform, expressed under conditions of inflammation and tumor growth. First, we researched the degradation of the COX-2 enzyme. We were able to demonstrate, that the COX-2 protein was ubiquitinated before prote...

  11. Single gene retrieval from thermally degraded DNA

    Indian Academy of Sciences (India)

    Unknown

    DNA thermal degradation was shown to occur via a singlet oxygen pathway. A comparative study of the ther- mal degradation of cellular DNA and isolated DNA showed that cellular ..... definite level of energy (e.g. depurination active energy,.

  12. 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

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

    OpenAIRE

    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...

  14. Flow accelerated organic coating degradation

    Science.gov (United States)

    Zhou, Qixin

    Applying organic coatings is a common and the most cost effective way to protect metallic objects and structures from corrosion. Water entry into coating-metal interface is usually the main cause for the deterioration of organic coatings, which leads to coating delamination and underfilm corrosion. Recently, flowing fluids over sample surface have received attention due to their capability to accelerate material degradation. A plethora of works has focused on the flow induced metal corrosion, while few studies have investigated the flow accelerated organic coating degradation. Flowing fluids above coating surface affect corrosion by enhancing the water transport and abrading the surface due to fluid shear. Hence, it is of great importance to understand the influence of flowing fluids on the degradation of corrosion protective organic coatings. In this study, a pigmented marine coating and several clear coatings were exposed to the laminar flow and stationary immersion. The laminar flow was pressure driven and confined in a flow channel. A 3.5 wt% sodium chloride solution and pure water was employed as the working fluid with a variety of flow rates. The corrosion protective properties of organic coatings were monitored inline by Electrochemical Impedance Spectroscopy (EIS) measurement. Equivalent circuit models were employed to interpret the EIS spectra. The time evolution of coating resistance and capacitance obtained from the model was studied to demonstrate the coating degradation. Thickness, gloss, and other topography characterizations were conducted to facilitate the assessment of the corrosion. The working fluids were characterized by Fourier Transform Infrared Spectrometer (FTIR) and conductivity measurement. The influence of flow rate, fluid shear, fluid composition, and other effects in the coating degradation were investigated. We conclude that flowing fluid on the coating surface accelerates the transport of water, oxygen, and ions into the coating, as

  15. 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

  16. Degradation analysis of thin film photovoltaic modules

    International Nuclear Information System (INIS)

    Radue, C.; Dyk, E.E. van

    2009-01-01

    Five thin film photovoltaic modules were deployed outdoors under open circuit conditions after a thorough indoor evaluation. Two technology types were investigated: amorphous silicon (a-Si:H) and copper indium gallium diselenide (CIGS). Two 14 W a-Si:H modules, labelled Si-1 and Si-2, were investigated. Both exhibited degradation, initially due to the well-known light-induced degradation described by Staebler and Wronski [Applied Physics Letters 31 (4) (1977) 292], and thereafter due to other degradation modes such as cell degradation. The various degradation modes contributing to the degradation of the a-Si:H modules will be discussed. The initial maximum power output (P MAX ) of Si-1 was 9.92 W, with the initial light-induced degradation for Si-1 ∼30% and a total degradation of ∼42%. For Si-2 the initial P MAX was 7.93 W, with initial light-induced degradation of ∼10% and a total degradation of ∼17%. Three CIGS modules were investigated: two 20 W modules labelled CIGS-1 and CIGS-2, and a 40 W module labelled CIGS-3. CIGS-2 exhibited stable performance while CIGS-1 and CIGS-3 exhibited degradation. CIGS is known to be stable over long periods of time, and thus the possible reasons for the degradation of the two modules are discussed.

  17. Degradation analysis of thin film photovoltaic modules

    Energy Technology Data Exchange (ETDEWEB)

    Radue, C., E-mail: chantelle.radue@nmmu.ac.z [Department of Physics, PO Box 77000, Nelson Mandela Metropolitan University, Port Elizabeth 6031 (South Africa); Dyk, E.E. van [Department of Physics, PO Box 77000, Nelson Mandela Metropolitan University, Port Elizabeth 6031 (South Africa)

    2009-12-01

    Five thin film photovoltaic modules were deployed outdoors under open circuit conditions after a thorough indoor evaluation. Two technology types were investigated: amorphous silicon (a-Si:H) and copper indium gallium diselenide (CIGS). Two 14 W a-Si:H modules, labelled Si-1 and Si-2, were investigated. Both exhibited degradation, initially due to the well-known light-induced degradation described by Staebler and Wronski [Applied Physics Letters 31 (4) (1977) 292], and thereafter due to other degradation modes such as cell degradation. The various degradation modes contributing to the degradation of the a-Si:H modules will be discussed. The initial maximum power output (P{sub MAX}) of Si-1 was 9.92 W, with the initial light-induced degradation for Si-1 approx30% and a total degradation of approx42%. For Si-2 the initial P{sub MAX} was 7.93 W, with initial light-induced degradation of approx10% and a total degradation of approx17%. Three CIGS modules were investigated: two 20 W modules labelled CIGS-1 and CIGS-2, and a 40 W module labelled CIGS-3. CIGS-2 exhibited stable performance while CIGS-1 and CIGS-3 exhibited degradation. CIGS is known to be stable over long periods of time, and thus the possible reasons for the degradation of the two modules are discussed.

  18. 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.

  19. 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.

  20. Modelling land degradation in IMAGE 2

    NARCIS (Netherlands)

    Hootsmans RM; Bouwman AF; Leemans R; Kreileman GJJ; MNV

    2001-01-01

    Food security may be threatened by loss of soil productivity as a result of human-induced land degradation. Water erosion is the most important cause of land degradation, and its effects are irreversible. This report describes the IMAGE land degradation model developed for describing current and

  1. 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)

  2. Using microorganisms to aid in hydrocarbon degradation

    International Nuclear Information System (INIS)

    Black, W.; Zamora, J.

    1993-01-01

    Aliphatic hydrocarbons are threatening the potable water supply and the aquatic ecosystem. Given the right microbial inhabitant(s), a large portion of these aliphatic hydrocarbons could be biodegraded before reaching the water supply. The authors' purpose is to isolate possible oil-degrading organisms. Soil samples were taken from hydrocarbon-laden soils at petroleum terminals, a petroleum refinery waste-treatment facility, a sewage-treatment plant grease collector, a site of previous bioremediation, and various other places. Some isolates known to be good degraders were obtained from culture collection services. These samples were plated on a 10w-30 multigrade motor oil solid medium to screen for aliphatic hydrocarbon degraders. The degrading organisms were isolated, identified, and tested (CO 2 evolution, BOD, and COD) to determine the most efficient degrader(s). Thirty-seven organisms were tested, and the most efficient degraders were Serratia marcescens, Escherichia coli, and Enterobacter agglomerans

  3. Enzymatic degradation of polycaprolactone–gelatin blend

    International Nuclear Information System (INIS)

    Banerjee, Aditi; Chatterjee, Kaushik; Madras, Giridhar

    2015-01-01

    Blends of polycaprolactone (PCL), a synthetic polymer and gelatin, natural polymer offer a optimal combination of strength, water wettability and cytocompatibility for use as a resorbable biomaterial. The enzymatic degradation of PCL, gelatin and PCL–gelatin blended films was studied in the presence of lipase (Novozym 435, immobilized) and lysozyme. Novozym 435 degraded the PCL films whereas lysozyme degraded the gelatin. Though Novozym 435 and lysozyme individually could degrade PCL–gelatin blended films, the combination of these enzymes showed the highest degradation of these blended films. Moreover, the enzymatic degradation was much faster when fresh enzymes were added at regular intervals. The changes in physico-chemical properties of polymer films due to degradation were studied by scanning electron microscopy, Fourier transform infrared spectroscopy and differential scanning calorimetry. These results have important implications for designing resorbable biomedical implants. (paper)

  4. Study of PP/montmorillonite composite degradation

    International Nuclear Information System (INIS)

    Baer, Marcia; Granado, Carlos J.F.

    2009-01-01

    The objective of this work was to produce composites of PP/sodium bentonite and PP/ organophilic bentonite through melt intercalation and analyze the degradation produced by ultraviolet irradiation. The XRD results showed that the samples of nature bentonite had better interaction with de polymer and produced intercalated nanocomposite. The effect of UV irradiation on degradation was observed after 24 hours of exposition. The samples showed the same photoproducts and at the same proportion until 240 hours of UV exposition; with 480 hours the organophilize bentonite composite showed higher degradation than other ones. The superficial cracks increased with degradation time. The degradation occurs due chromophores impurities presented in the samples, thus samples with sodium clay show higher degradation, and organophilic clay contains ammonium salt that contribute to increase the degradation. (author)

  5. STRUCTURAL PERFORMANCE OF DEGRADED REINFORCED CONCRETE MEMBERS

    International Nuclear Information System (INIS)

    Braverman, J.I.; Miller, C.A.; Ellingwood, B.R.; Naus, D.J.; Hofmayer, C.H.; Bezler, P.; Chang, T.Y.

    2001-01-01

    This paper describes the results of a study to evaluate, in probabilistic terms, the effects of age-related degradation on the structural performance of reinforced concrete members at nuclear power plants. The paper focuses on degradation of reinforced concrete flexural members and shear walls due to the loss of steel reinforcing area and loss of concrete area (cracking/spalling). Loss of steel area is typically caused by corrosion while cracking and spalling can be caused by corrosion of reinforcing steel, freeze-thaw, or aggressive chemical attack. Structural performance in the presence of uncertainties is depicted by a fragility (or conditional probability of failure). The effects of degradation on the fragility of reinforced concrete members are calculated to assess the potential significance of various levels of degradation. The fragility modeling procedures applied to degraded concrete members can be used to assess the effects of degradation on plant risk and can lead to the development of probability-based degradation acceptance limits

  6. Early detection of materials degradation

    Science.gov (United States)

    Meyendorf, Norbert

    2017-02-01

    Lightweight components for transportation and aerospace applications are designed for an estimated lifecycle, taking expected mechanical and environmental loads into account. The main reason for catastrophic failure of components within the expected lifecycle are material inhomogeneities, like pores and inclusions as origin for fatigue cracks, that have not been detected by NDE. However, material degradation by designed or unexpected loading conditions or environmental impacts can accelerate the crack initiation or growth. Conventional NDE methods are usually able to detect cracks that are formed at the end of the degradation process, but methods for early detection of fatigue, creep, and corrosion are still a matter of research. For conventional materials ultrasonic, electromagnetic, or thermographic methods have been demonstrated as promising. Other approaches are focused to surface damage by using optical methods or characterization of the residual surface stresses that can significantly affect the creation of fatigue cracks. For conventional metallic materials, material models for nucleation and propagation of damage have been successfully applied for several years. Material microstructure/property relations are well established and the effect of loading conditions on the component life can be simulated. For advanced materials, for example carbon matrix composites or ceramic matrix composites, the processes of nucleation and propagation of damage is still not fully understood. For these materials NDE methods can not only be used for the periodic inspections, but can significantly contribute to the material scientific knowledge to understand and model the behavior of composite materials.

  7. Environmental Degradation: Causes and Consequences

    Directory of Open Access Journals (Sweden)

    Swati Tyagi

    2014-08-01

    Full Text Available The subject of environmental economics is at the forefront of the green debate: the environment can no longer be viewed as an entity separate from the economy. Environmental degradation is of many types and have many consequences. To address this challenge a number of studies have been conducted in both developing and developed countries applying different methods to capture health benefits from improved environmental quality. Minimizing exposure to environmental risk factors by enhancing air quality and access to improved sources of drinking and bathing water, sanitation and clean energy is found to be associated with significant health benefits and can contribute significantly to the achievement of the Millennium Development Goals of environmental sustainability, health and development. In this paper, I describe the national and global causes and consequences of environmental degradation and social injustice. This paper provides a review of the literature on studies associated with reduced environmental risk and in particular focusing on reduced air pollution, enhanced water quality and climate change mitigation.

  8. Charcoal production and environmental degradation

    International Nuclear Information System (INIS)

    Hosier, R.H.

    1993-01-01

    This paper examines the environmental impacts of continued tree harvesting for charcoal production to supply the urban areas in Tanzania. Woodlands appear to recover relatively well following harvesting for charcoal production. Selective harvesting, where the high quality, low cost fuel production species and specimens are culled first from a piece of land, serves to maintain the viability of the woodlands resource while providing charcoal. This recovery period can be prolonged through any number of human induced activities, such as heavy grazing, multiple burns and extended cultivation periods. At the same time, post-harvest management techniques, such as coppice management, sprout protection and fertilization, can also improve the ability of woodlands to recover following harvesting. The environmental history of a given area determines why certain areas continue to be strong suppliers of woodfuel while others are not. For example, Shinyanga started from a low productivity base and has been degraded by successive waves of tree harvesting compounded by heavy grazing pressure. It is this multiple complex of pressures over a long period of time on land which is intrinsically of low productivity, and not the harvesting of woodlands for fuels, which has led to the environmental degradation in these areas. (author)

  9. Microbial Enzymatic Degradation of Biodegradable Plastics.

    Science.gov (United States)

    Roohi; Bano, Kulsoom; Kuddus, Mohammed; Zaheer, Mohammed R; Zia, Qamar; Khan, Mohammed F; Ashraf, Ghulam Md; Gupta, Anamika; Aliev, Gjumrakch

    2017-01-01

    The renewable feedstock derived biodegradable plastics are important in various industries such as packaging, agricultural, paper coating, garbage bags and biomedical implants. The increasing water and waste pollution due to the available decomposition methods of plastic degradation have led to the emergence of biodegradable plastics and biological degradation with microbial (bacteria and fungi) extracellular enzymes. The microbes utilize biodegradable polymers as the substrate under starvation and in unavailability of microbial nutrients. Microbial enzymatic degradation is suitable from bioremediation point of view as no waste accumulation occurs. It is important to understand the microbial interaction and mechanism involved in the enzymatic degradation of biodegradable plastics under the influence of several environmental factors such as applied pH, thermo-stability, substrate molecular weight and/or complexity. To study the surface erosion of polymer film is another approach for hydrolytic degradation characteristion. The degradation of biopolymer is associated with the production of low molecular weight monomer and generation of carbon dioxide, methane and water molecule. This review reported the degradation study of various existing biodegradable plastics along with the potent degrading microbes (bacteria and fungi). Patents available on plastic biodegradation with biotechnological significance is also summarized in this paper. This paper assesses that new disposal technique should be adopted for the degradation of polymers and further research is required for the economical production of biodegradable plastics along with their enzymatic degradation. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

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

    Directory of Open Access Journals (Sweden)

    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.

  11. Bioresorption and degradation of biomaterials.

    Science.gov (United States)

    Das, Debarun; Zhang, Ziyang; Winkler, Thomas; Mour, Meenakshi; Gunter, Christina; Morlock, Michael; Machens, Hans-Gunther; Schilling, Arndt F

    2012-01-01

    The human body is a composite structure, completely constructed of biodegradable materials. This allows the cells of the body to remove and replace old or defective tissue with new material. Consequently, artificial resorbable biomaterials have been developed for application in regenerative medicine. We discuss here advantages and disadvantages of these bioresorbable materials for medical applications and give an overview of typically used metals, ceramics and polymers. Methods for the quantification of bioresorption in vitro and in vivo are described. The next challenge will be to better understand the interface between cell and material and to use this knowledge for the design of “intelligent” materials that can instruct the cells to build specific tissue geometries and degrade in the process.

  12. Permafrost degradation in West Greenland

    DEFF Research Database (Denmark)

    Foged, Niels Nielsen; Ingeman-Nielsen, Thomas

    2012-01-01

    Important aspects of civil engineering in West Greenland relate to the presence of permafrost and mapping of the annual and future changes in the active layer due to the ongoing climatically changes in the Arctic. The Arctic Technology Centre (ARTEK) has worked more than 10 years on this topic...... and the first author has been involved since 1970 in engineering geology, geotechnical engineering and permafrost related studies for foundation construction and infrastructures in towns and communities mainly in West Greenland. We have since 2006 together with the Danish Meteorological Institute, Greenland...... Survey (ASIAQ) and the University of Alaska Fairbanks carried out the US NSF funded project ARC-0612533: Recent and future permafrost variability, retreat and degradation in Greenland and Alaska: An integrated approach. This contribution will present data and observations from the towns Ilulissat...

  13. Bacterial Degradation of Aromatic Compounds

    Directory of Open Access Journals (Sweden)

    Qing X. Li

    2009-01-01

    Full Text Available Aromatic compounds are among the most prevalent and persistent pollutants in the environment. Petroleum-contaminated soil and sediment commonly contain a mixture of polycyclic aromatic hydrocarbons (PAHs and heterocyclic aromatics. Aromatics derived from industrial activities often have functional groups such as alkyls, halogens and nitro groups. Biodegradation is a major mechanism of removal of organic pollutants from a contaminated site. This review focuses on bacterial degradation pathways of selected aromatic compounds. Catabolic pathways of naphthalene, fluorene, phenanthrene, fluoranthene, pyrene, and benzo[a]pyrene are described in detail. Bacterial catabolism of the heterocycles dibenzofuran, carbazole, dibenzothiophene, and dibenzodioxin is discussed. Bacterial catabolism of alkylated PAHs is summarized, followed by a brief discussion of proteomics and metabolomics as powerful tools for elucidation of biodegradation mechanisms.

  14. Soil physical land degradation processes

    Science.gov (United States)

    Horn, Rainer

    2017-04-01

    According to the European Soil Framework Directive (2006) soil compaction is besides water and wind erosion one of the main physical reasons and threats of soil degradation. It is estimated, that 32% of the subsoils in Europe are highly degraded and 18% moderately vulnerable to compaction. The problem is not limited to crop land or forest areas (especially because of non-site adjusted harvesting machines) but is also prevalent in rangelands and grassland, and even in so called natural non-disturbed systems. The main reasons for an intense increase in compacted agricultural or forested regions are the still increasing masses of the machines as well the increased frequency of wheeling under non favorable site conditions. Shear and vibration induced soil deformation enhances the deterioration of soil properties especially if the soil water content is very high and the internal soil strength very low. The same is true for animal trampling in combination with overgrazing of moist to wet pastures which subsequently causes a denser (i.e. reduced proportion of coarse pores with smaller continuity) but still structured soil horizons and will finally end in a compacted platy structure. In combination with high water content and shearing due to trampling therefore results in a complete muddy homogeneous soil with no structure at all. (Krümmelbein et al. 2013) Site managements of arable, forestry or horticulture soils requires a sufficiently rigid pore system which guarantees water, gas and heat exchange, nutrient transport and adsorption as well as an optimal rootability in order to avoid subsoil compaction. Such pore system also guarantees a sufficient microbial activity and composition in order to also decompose the plant etc. debris. It is therefore essential that well structured horizons dominate in soils with at best subangular blocky structure or in the top A- horizons a crumbly structure due to biological activity. In contrast defines the formation of a platy

  15. Enzyme stabilization for pesticide degradation

    Energy Technology Data Exchange (ETDEWEB)

    Rivers, D.B.; Frazer, F.R. III; Mason, D.W.; Tice, T.R.

    1988-01-01

    Enzymes offer inherent advantages and limitations as active components of formulations used to decontaminate soil and equipment contaminated with toxic materials such as pesticides. Because of the catalytic nature of enzymes, each molecule of enzyme has the potential to destroy countless molecules of a contaminating toxic compound. This degradation takes place under mild environmental conditions of pH, temperature, pressure, and solvent. The basic limitation of enzymes is their degree of stability during storage and application conditions. Stabilizing methods such as the use of additives, covalent crosslinking, covalent attachment, gel entrapment, and microencapsulation have been directed developing an enzyme preparation that is stable under extremes of pH, temperature, and exposure to organic solvents. Initial studies were conducted using the model enzymes subtilisin and horseradish peroxidase.

  16. CELLULOSE DEGRADATION BY OXIDATIVE ENZYMES

    Directory of Open Access Journals (Sweden)

    Maria Dimarogona

    2012-09-01

    Full Text Available Enzymatic degradation of plant biomass has attracted intensive research interest for the production of economically viable biofuels. Here we present an overview of the recent findings on biocatalysts implicated in the oxidative cleavage of cellulose, including polysaccharide monooxygenases (PMOs or LPMOs which stands for lytic PMOs, cellobiose dehydrogenases (CDHs and members of carbohydrate-binding module family 33 (CBM33. PMOs, a novel class of enzymes previously termed GH61s, boost the efficiency of common cellulases resulting in increased hydrolysis yields while lowering the protein loading needed. They act on the crystalline part of cellulose by generating oxidized and non-oxidized chain ends. An external electron donor is required for boosting the activity of PMOs. We discuss recent findings concerning their mechanism of action and identify issues and questions to be addressed in the future.

  17. The degradation of Brazilian socioeconomics

    Directory of Open Access Journals (Sweden)

    MARCUS ALBAN

    2018-03-01

    Full Text Available ABSTRACT In recent years, a number of illegal activities operated under the radar of conventional analysis have taken place in Brazil. This study proposes an Extended Keynesian Model in order to understand this phenomenon, a model that explains that crises happen because of the replacement of productive activities with unproductive and destructive activities. The model is used here to examine Brazil’s socioeconomic history since the institution of the economic plan that established the actual currency “Real” (R$, concluding that as the plan’s concern was predominantly with stabilization and not growth, productive activities have never been promoted on an appropriate scale. This has paved the way for the advancement of unproductive and destructive activities which have ultimately led to the country’s increasing degradation.

  18. Recovering of images degraded by atmosphere

    Science.gov (United States)

    Lin, Guang; Feng, Huajun; Xu, Zhihai; Li, Qi; Chen, Yueting

    2017-08-01

    Remote sensing images are seriously degraded by multiple scattering and bad weather. Through the analysis of the radiative transfer procedure in atmosphere, an image atmospheric degradation model considering the influence of atmospheric absorption multiple scattering and non-uniform distribution is proposed in this paper. Based on the proposed model, a novel recovering method is presented to eliminate atmospheric degradation. Mean-shift image segmentation and block-wise deconvolution are used to reduce time cost, retaining a good result. The recovering results indicate that the proposed method can significantly remove atmospheric degradation and effectively improve contrast compared with other removal methods. The results also illustrate that our method is suitable for various degraded remote sensing, including images with large field of view (FOV), images taken in side-glance situations, image degraded by atmospheric non-uniform distribution and images with various forms of clouds.

  19. Nanoparticles from Degradation of Biodegradable Plastic Mulch

    Science.gov (United States)

    Flury, Markus; Sintim, Henry; Bary, Andy; English, Marie; Schaefer, Sean

    2017-04-01

    Plastic mulch films are commonly used in crop production. They provide multiple benefits, including control of weeds and insects, increase of soil and air temperature, reduction of evaporation, and prevention of soil erosion. The use of plastic mulch film in agriculture has great potential to increase food production and security. Plastic mulch films must be retrieved and disposed after usage. Biodegradable plastic mulch films, who can be tilled into the soil after usage offer great benefits as alternative to conventional polyethylene plastic. However, it has to be shown that the degradation of these mulches is complete and no micro- and nanoparticles are released during degradation. We conducted a field experiment with biodegradable mulches and tested mulch degradation. Mulch was removed from the field after the growing season and composted to facilitate degradation. We found that micro- and nanoparticles were released during degradation of the mulch films in compost. This raises concerns about degradation in soils as well.

  20. Bacteria-mediated bisphenol A degradation.

    Science.gov (United States)

    Zhang, Weiwei; Yin, Kun; Chen, Lingxin

    2013-07-01

    Bisphenol A (BPA) is an important monomer in the manufacture of polycarbonate plastics, food cans, and other daily used chemicals. Daily and worldwide usage of BPA and BPA-contained products led to its ubiquitous distribution in water, sediment/soil, and atmosphere. Moreover, BPA has been identified as an environmental endocrine disruptor for its estrogenic and genotoxic activity. Thus, BPA contamination in the environment is an increasingly worldwide concern, and methods to efficiently remove BPA from the environment are urgently recommended. Although many factors affect the fate of BPA in the environment, BPA degradation is mainly depended on the metabolism of bacteria. Many BPA-degrading bacteria have been identified from water, sediment/soil, and wastewater treatment plants. Metabolic pathways of BPA degradation in specific bacterial strains were proposed, based on the metabolic intermediates detected during the degradation process. In this review, the BPA-degrading bacteria were summarized, and the (proposed) BPA degradation pathway mediated by bacteria were referred.

  1. Robust PV Degradation Methodology and Application

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, Dirk [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Deline, Christopher A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Kurtz, Sarah [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Kimball, Greg [SunPower; Anderson, Mike [SunPower

    2017-11-15

    The degradation rate plays an important role in predicting and assessing the long-term energy generation of PV systems. Many methods have been proposed for extracting the degradation rate from operational data of PV systems, but most of the published approaches are susceptible to bias due to inverter clipping, module soiling, temporary outages, seasonality, and sensor degradation. In this manuscript, we propose a methodology for determining PV degradation leveraging available modeled clear-sky irradiance data rather than site sensor data, and a robust year-over-year (YOY) rate calculation. We show the method to provide reliable degradation rate estimates even in the case of sensor drift, data shifts, and soiling. Compared with alternate methods, we demonstrate that the proposed method delivers the lowest uncertainty in degradation rate estimates for a fleet of 486 PV systems.

  2. CLAD DEGRADATION - FEPS SCREENING ARGUMENTS

    International Nuclear Information System (INIS)

    R. Schreiner

    2004-01-01

    The purpose of this report is to evaluate and document the screening of the clad degradation features, events, and processes (FEPs) with respect to modeling used to support the Total System Performance Assessment-License Application (TSPA-LA). This report also addresses the effect of certain FEPs on both the cladding and the commercial spent nuclear fuel (CSNF), DOE-owned spent nuclear fuel (DSNF), and defense high-level waste (DHLW) waste forms, as appropriate to address the effects on multiple materials and both components (FEPs 2.1.09.09.0A, 2.1.09.11.0A, 2.1.11.05.0A, 2.1.12.02.0A, and 2.1.12.03.0A). These FEPs are expected to affect the repository performance during the postclosure regulatory period of 10,000 years after permanent closure. Table 1-1 provides the list of cladding FEPs, including their screening decisions (include or exclude). The primary purpose of this report is to identify and document the analysis, screening decision, and TSPA-LA disposition (for included FEPs) or screening argument (for excluded FEPs) for these FEPs related to clad degradation. In some cases, where a FEP covers multiple technical areas and is shared with other FEP reports, this report may provide only a partial technical basis for the screening of the FEP. The full technical basis for shared FEPs is addressed collectively by the sharing FEP reports. The screening decisions and associated TSPA-LA dispositions or screening arguments from all of the FEP reports are cataloged in a project-specific FEPs database

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

    Institute of Scientific and Technical Information of China (English)

    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.

  4. Durability Improvements Through Degradation Mechanism Studies

    Energy Technology Data Exchange (ETDEWEB)

    Borup, Rodney L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mukundan, Rangachary [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Spernjak, Dusan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Baker, Andrew M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lujan, Roger W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Langlois, David Alan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ahluwalia, Rajesh [Argonne National Lab. (ANL), Argonne, IL (United States); Papadia, D. D. [Argonne National Lab. (ANL), Argonne, IL (United States); Weber, Adam Z. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Kusoglu, Ahmet [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Shi, Shouwnen [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); More, K. L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Grot, Steve [Ion Power, New Castle, DE (United States)

    2015-08-03

    The durability of polymer electrolyte membrane (PEM) fuel cells is a major barrier to the commercialization of these systems for stationary and transportation power applications. By investigating cell component degradation modes and defining the fundamental degradation mechanisms of components and component interactions, new materials can be designed to improve durability. To achieve a deeper understanding of PEM fuel cell durability and component degradation mechanisms, we utilize a multi-institutional and multi-disciplinary team with significant experience investigating these phenomena.

  5. Thermal degradation of organo-soluble polyimides

    Institute of Scientific and Technical Information of China (English)

    黄俐研; 史燚; 金熹高

    1999-01-01

    The thermal degradation behavior of two organo-soluble polyimides was investigated by high resolution pyrolysis-gas chromatography/mass spectrometry. The pyrolyzates of the polymers at various temperatures were identified and characterized quantitatively. The relationship between the polymer structure and pyrolyzate distribution was discussed. The kinetic parameters of the thermal degradation were calculated based on thermogravimetric measurements. Finally, the thermal degradation mechanism for the polymers was suggested.

  6. 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

    Directory of Open Access Journals (Sweden)

    Márcia Regina Albertoni

    2007-09-01

    Full Text Available

    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.

  7. Litter decomposition and nutrient release from Brachiaria, Sorghum and soybean in no-tillage areas in the Cerrado region, GoiásDecomposição e liberação de nutrientes da palhada de braquiária, sorgo e soja em áreas de plantio direto no cerrado goiano

    Directory of Open Access Journals (Sweden)

    Celeste Queiroz Rossi

    2013-09-01

    Full Text Available The evaluation of plant litter decomposition added to the soil by cover crops provides a better understanding of nutrient supply to crops of commercial interest. The objective of this study was to evaluate the decomposition rate and dynamics of release of N, P and K in crop residues from crop of soybeans grown in Oxisol under no tillage. The residues used were Congo grass (Brachiaria ruziziensis and sorghum (Sorghum bicolor L. Moench. The average production of Congo grass biomass + soybean was 6.1 Mg ha-1 and soybean + sorghum was 3.8 Mg ha-1. The dry matter decomposition and nutrient release were monitored at 15, 30, 60, 90, 120 days using bags containing residues deposited on the soil surface. A mathematical model was used to describe the litter decomposition and N, P, K release and the decomposition constant (k and half-life (T1/2 were calculated. The values of T1/2 for dry matter were 154 and 258 days for Brachiaria + soybean and soybean + sorghum, respectively, in the dry season and 99 and 119 days in the rainy season. The nutrient with the lowest T1/2 was P, followed by K and N in both litters and evaluated at different times. A avaliação da decomposição dos resíduos vegetais adicionados ao solo pelas plantas de cobertura permite uma melhor compreensão do fornecimento de nutrientes para as culturas de interesse comercial. O objetivo do trabalho foi avaliar as taxas de decomposição e a dinâmica da liberação de N, P e K de resíduos culturais na entressafra da soja cultivada em Latossolo Vermelho, sob plantio direto. Os resíduos utilizados foram braquiária (Brachiaria ruziziensis R. Germ. & Evrard e o sorgo (Sorghum bicolor L. Moench. A produção média de biomassa seca de braquiária + soja foi de 6,1 Mg ha-1 e do sorgo + soja foi de 3,8 Mg ha-1 . A decomposição da matéria seca e a liberação de nutrientes foram monitoradas aos 15, 30, 60, 90, 120 dias por meio de sacolas contendo resíduos culturais depositados na superf

  8. Simulating Degradation Data for Prognostic Algorithm Development

    Data.gov (United States)

    National Aeronautics and Space Administration — PHM08 Challenge Dataset is now publicly available at the NASA Prognostics Respository + Download INTRODUCTION - WHY SIMULATE DEGRADATION DATA? Of various challenges...

  9. Photovoltaic Degradation Rates -- An Analytical Review

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, D. C.; Kurtz, S. R.

    2012-06-01

    As photovoltaic penetration of the power grid increases, accurate predictions of return on investment require accurate prediction of decreased power output over time. Degradation rates must be known in order to predict power delivery. This article reviews degradation rates of flat-plate terrestrial modules and systems reported in published literature from field testing throughout the last 40 years. Nearly 2000 degradation rates, measured on individual modules or entire systems, have been assembled from the literature, showing a median value of 0.5%/year. The review consists of three parts: a brief historical outline, an analytical summary of degradation rates, and a detailed bibliography partitioned by technology.

  10. Degradation Mechanisms of Military Coating Systems

    National Research Council Canada - National Science Library

    Keene, L. T; Halada, G. P; Clayton, C. R; Kosik, W. E; McKnight, S. H

    2004-01-01

    This work describes the development and application of specialized characterization techniques used to study the environmental degradation mechanisms of organic coating systems employed by the United...

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

    Directory of Open Access Journals (Sweden)

    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.

  12. Intake, digestibility, ruminal parameters, and microbial protein synthesis in crossbred steers fed diets based on Brachiaria grass silage and sorghum silage Consumo, digestibilidade, parâmetros ruminais e síntese de proteína microbiana em novilhos cruzados alimentados com dietas a base de silagem de braquiária e silagem de sorgo

    Directory of Open Access Journals (Sweden)

    F.H.M. Chizzotti

    2009-12-01

    Full Text Available A trial was carried out with four Holstein x Nellore crossbred steers (225±22kg of BW fitted with ruminal and abomasal cannulaes in a 4 x 4 Latin Square design to evaluate the intake and the total and partial apparent digestibilities of nutrients, ruminal parameters, and microbial synthesis. Diets consisted of 60% silage and 40% concentrate formulated to be isonitrogenous (12.5% of crude protein, dry matter basis. Treatments consisted of different proportions of Brachiaria brizantha grass silage and sorghum silage: 100:0; 67:33; 33:67, and 0:100%, respectively, on dry matter basis. The intake of dry matter, organic matter, crude protein, ether extract, non-fiber carbohydrates, and total digestible nutrients linearly increased (P0.05 by the treatments. The use of 67% of sorghum silage and 33% of grass silage increased intake and digestibility of nutrients without affecting ruminal pH, ruminal NH3-N, and microbial efficiency.Realizou-se um estudo com quatro novilhos cruzados Holandês x Nelore (225±22kg de peso vivo, canulados no rúmen e abomaso, distribuídos em quadrado latino 4 x 4 para avaliar o efeito de diferentes proporções de silagem de Braquiária brizantha e silagem de sorgo sobre o consumo e a digestibilidade dos nutrientes no trato digestório total e parcial, sobre os parâmetros ruminais e sobre a eficiência microbiana. As dietas continham 60% de volumoso e 40% de concentrado e foram formuladas para serem isonitrogenadas (12,5% de proteína bruta na matéria seca. Os tratamentos consistiram em diferentes proporções de silagens de Brachiaria brizantha e de sorgo: 100:0; 67:33; 33:67 e 0:100%, respectivamente (% da matéria seca. O consumo de matéria seca, matéria orgânica, proteína bruta, extrato etéreo, carboidratos não-fibrosos e nutrientes digestíveis totais aumentou linearmente (P0,05. O uso de 67% de silagem de sorgo com 33% de silagem de braquiária aumentou o consumo e a digestibilidade dos nutrientes sem afetar

  13. Atividade alelopática de substâncias químicas isoladas do Capim-Marandu e suas variações em função do pH Allelopathic activity of chemical substances isolated from Brachiaria brizantha cv. Marandu and their variations in function of pH

    Directory of Open Access Journals (Sweden)

    L.S. Santos

    2008-01-01

    Full Text Available Este trabalho teve por objetivos isolar, identificar e caracterizar a atividade alelopática de substâncias químicas produzidas pela Brachiaria brizantha cv. Marandu e determinar as variações na atividade dessas substâncias em função da variação do pH da solução. A atividade alelopática foi realizada em bioensaios de germinação e desenvolvimento da radícula e do hipocótilo, utilizando as plantas daninhas malícia (Mimosa pudica e mata-pasto (Senna obtusifolia como receptoras. Os efeitos do pH foram analisados na faixa de 3,0 a 9,0. Os triterpenos pentacíclicos friedelina e epifriedelinol isolados da parte aérea de B. brizantha apresentaram baixa atividade inibitória na germinação de sementes e no desenvolvimento da radícula e do hipocótilo das duas plantas daninhas. As duas substâncias apresentaram comportamento diferenciado em relação à variação do pH da solução, com inibições mais marcantes em relação à planta daninha mata-pasto.This work aimed to isolate, identify and determine the allelopathic activity of the chemical substances produced by Brachiaria brizantha cv. Marandu and to verify the effects of the pH in the solution on the activity of these compounds. The allelopathic activity was evaluated based on germination bioassays and radicle and hypocotyl growth using the species 'malícia' (Mimosa pudica and 'mata-pasto' (Senna obtusifolia as receptors. The effect of pH was analyzed in a range from 3.0 to 9.0. The pentacyclic triterpenes friedelin and epifriefelinol isolated from the shoots of B. brizantha showed a low inhibitory activity against seed germination and radicle and hypocotyl growth of the two receptor plants evaluated. The pentacyclic triterpenes friedelin and epifrifelinol presented differentiated behaviors in relation to the pH variation in the solution, with stronger inhibition activity against the weed 'mata-pasto'.

  14. 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

    Directory of Open Access Journals (Sweden)

    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

  15. Thermal degradation of glucosinolates in red cabbage

    NARCIS (Netherlands)

    Oerlemans, K.; Barrett, D.M.; Bosch Suades, C.; Verkerk, R.; Dekker, M.

    2006-01-01

    Thermal degradation of individual glucosinolates within the plant matrix was studied. Red cabbage samples were heated at different temperatures for various times. To rule out the influence of enzymatic breakdown and to focus entirely on the thermal degradation of glucosinolates, myrosinase was

  16. Degradation mechanisms in organic photovoltaic devices

    NARCIS (Netherlands)

    Grossiord, Nadia; Kroon, Jan M.; Andriessen, Ronn; Blom, Paul W. M.

    In the present review, the main degradation mechanisms occurring in the different layer stacking (i.e. photoactive layer, electrode, encapsulation film, interconnection) of polymeric organic solar cells and modules are discussed. Bulk and interfacial, as well as chemical and physical degradation

  17. Pt/C Fuel Cell Catalyst Degradation

    DEFF Research Database (Denmark)

    Zana, Alessandro

    This thesis investigates the degradation behavior of Pt/C catalysts under simulated automotive conditions. By using the “tool box” synthesis method the Pt loading has been changed from low to high Pt loadings, therefore permitting to study the role of Pt on the degradation of high surface area (H...

  18. Single gene retrieval from thermally degraded DNA

    Indian Academy of Sciences (India)

    To simulate single gene retrieval from ancient DNA, several related factors have been investigated. By monitoring a 889 bp polymerase chain reaction (PCR) product and genomic DNA degradation, we find that heat and oxygen (especially heat) are both crucial factors influencing DNA degradation. The heat influence ...

  19. Geodiversity and land degradation in Hungary

    Science.gov (United States)

    Őrsi, Anna

    2014-05-01

    Geodiversity represents a variety of natural values, but they are threatened by a series of anthropogenic activities and land degradation processes. Their effect depends on the intensity of the processes and the sensitivity of the area in question. As a consequence of land degradation processes not only biodiversity but also geodiversity can be damaged and deteriorated. The appearance of the natural landscape changes and natural processes may not have a decisive role in landscape development any more. Some of the damages are irreversible because fundamental changes happen in the landscape, or the processes having created the original forms are no longer in operation. Small scale land degradation processes may be reversible if nature is still capable of reproducing the original state. The most important land degradation processes are desertification and soil erosion. Mining, waste disposal, urbanisation and construction activities, agriculture, inaccurate forest and water management, tourism, unsuitable land use can also lead to severe land degradation problems. The objective of the paper is to show Hungarian examples to all land degradation processes that threaten geodiversity. The results will be shown on a series of maps showing land degradation processes endangering geodiversity in Hungary. A detailed analysis of smaller study sites will be provided to show the effects of certain land degradation processes on landform development and on the changes of geodiversity. This research is supported by the Hungarian Scientific Research Fund (OTKA), project Nr. 10875.

  20. A systems approach to restoring degraded drylands

    Science.gov (United States)

    Jeremy J. James; Roger L. Sheley; Todd Erickson; Kimberly S. Rollins; Michael H. Taylor; Kingsley W. Dixon

    2013-01-01

    Drylands support over 2 billion people and are major providers of critical ecosystem goods and services across the globe. Drylands, however, are one of the most susceptible biomes to degradation. International programmes widely recognize dryland restoration as key to combating global dryland degradation and ensuring future global sustainability. While the need to...

  1. Lignin-degrading enzyme activities.

    Science.gov (United States)

    Chen, Yi-ru; Sarkanen, Simo; Wang, Yun-Yan

    2012-01-01

    Over the past three decades, the activities of four kinds of enzyme have been purported to furnish the mechanistic foundations for macromolecular lignin depolymerization in decaying plant cell walls. The pertinent fungal enzymes comprise lignin peroxidase (with a relatively high redox potential), manganese peroxidase, an alkyl aryl etherase, and laccase. The peroxidases and laccase, but not the etherase, are expressed extracellularly by white-rot fungi. A number of these microorganisms exhibit a marked preference toward lignin in their degradation of lignocellulose. Interestingly, some white-rot fungi secrete both kinds of peroxidase but no laccase, while others that are equally effective express extracellular laccase activity but no peroxidases. Actually, none of these enzymes has been reported to possess significant depolymerase activity toward macromolecular lignin substrates that are derived with little chemical modification from the native biopolymer. Here, the assays commonly employed for monitoring the traditional fungal peroxidases, alkyl aryl etherase, and laccase are described in their respective contexts. A soluble native polymeric substrate that can be isolated directly from a conventional milled-wood lignin preparation is characterized in relation to its utility in next-generation lignin-depolymerase assays.

  2. Synaptic Synthesis, Dephosphorylation, and Degradation

    Science.gov (United States)

    La Montanara, Paolo; Rusconi, Laura; Locarno, Albina; Forti, Lia; Barbiero, Isabella; Tramarin, Marco; Chandola, Chetan; Kilstrup-Nielsen, Charlotte; Landsberger, Nicoletta

    2015-01-01

    Mutations in the X-linked CDKL5 (cyclin-dependent kinase-like 5) gene have been associated with several forms of neurodevelopmental disorders, including atypical Rett syndrome, autism spectrum disorders, and early infantile epileptic encephalopathy. Accordingly, loss of CDKL5 in mice results in autistic-like features and impaired neuronal communication. Although the biological functions of CDKL5 remain largely unknown, recent pieces of evidence suggest that CDKL5 is involved in neuronal plasticity. Herein, we show that, at all stages of development, neuronal depolarization induces a rapid increase in CDKL5 levels, mostly mediated by extrasomatic synthesis. In young neurons, this induction is prolonged, whereas in more mature neurons, NMDA receptor stimulation induces a protein phosphatase 1-dependent dephosphorylation of CDKL5 that is mandatory for its proteasome-dependent degradation. As a corollary, neuronal activity leads to a prolonged induction of CDKL5 levels in immature neurons but to a short lasting increase of the kinase in mature neurons. Recent results demonstrate that many genes associated with autism spectrum disorders are crucial components of the activity-dependent signaling networks regulating the composition, shape, and strength of the synapse. Thus, we speculate that CDKL5 deficiency disrupts activity-dependent signaling and the consequent synapse development, maturation, and refinement. PMID:25555910

  3. Degraded character recognition based on gradient pattern

    Science.gov (United States)

    Babu, D. R. Ramesh; Ravishankar, M.; Kumar, Manish; Wadera, Kevin; Raj, Aakash

    2010-02-01

    Degraded character recognition is a challenging problem in the field of Optical Character Recognition (OCR). The performance of an optical character recognition depends upon printed quality of the input documents. Many OCRs have been designed which correctly identifies the fine printed documents. But, very few reported work has been found on the recognition of the degraded documents. The efficiency of the OCRs system decreases if the input image is degraded. In this paper, a novel approach based on gradient pattern for recognizing degraded printed character is proposed. The approach makes use of gradient pattern of an individual character for recognition. Experiments were conducted on character image that is either digitally written or a degraded character extracted from historical documents and the results are found to be satisfactory.

  4. Quantitative accelerated degradation testing: Practical approaches

    International Nuclear Information System (INIS)

    Mohammadian, S. Hossein; Ait-Kadi, Daoud; Routhier, Francois

    2010-01-01

    The concept of accelerated testing by tracking degradation of samples over test time needs to be developed for reliability estimation. This paper aims at proposing practical approaches to conduct accelerated degradation testing on new and available used samples. For this purpose, product failure is related to a suitable physical property. Then, its failure time is defined as the expected time in which its property reaches the critical level. Degradation model of field samples returned from service due to a degrading failure mode has been estimated based on the least square method, and available gap between manufacturer criterion and user's claim (to report a failure) has also been discussed. For a product under some stresses, a general formula has been proposed by the superposition principle in order to estimate its degradation for independent and dependent failure modes. If used samples are available, and acceleration factor of the related test is unknown, partial aging method has been presented to considerably shorten the test time.

  5. Degradation of multiwall carbon nanotubes by bacteria

    International Nuclear Information System (INIS)

    Zhang, Liwen; Petersen, Elijah J.; Habteselassie, Mussie Y.; Mao, Liang; Huang, Qingguo

    2013-01-01

    Understanding the environmental transformation of multiwall carbon nanotubes (MWCNTs) is important to their life cycle assessment and potential environmental impacts. We report that a bacterial community is capable of degrading 14 C-labeled MWCNTs into 14 CO 2 in the presence of an external carbon source via co-metabolism. Multiple intermediate products were detected, and genotypic characterization revealed three possible microbial degraders: Burkholderia kururiensis, Delftia acidovorans, and Stenotrophomonas maltophilia. This result suggests that microbe/MWCNTs interaction may impact the long-term fate of MWCNTs. Highlights: •Mineralization of MWCNTs by a bacterial community was observed. •The mineralization required an external carbon source. •Multiple intermediate products were identified in the MWCNT degrading culture. •Three bacterial species were found likely responsible for MWCNT degradation. -- The 14 C-labeled multiwall carbon nanotubes can be degraded to 14 CO 2 and other byproducts by a bacteria community under natural conditions

  6. Radiation degradation of alginate and chitosan

    Energy Technology Data Exchange (ETDEWEB)

    Nagasawa, Naotsugu; Mitomo, Hiroshi [Department of Biological and Chemical Engineering, Faculty of Engineering, Gunma University, Kiryu, Gunma (Japan); Yoshii, Fumio; Kume, Tamikazu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2000-03-01

    Alginate and chitosan were irradiated in solid or aqueous solution condition with Co{sup 60} gamma rays in the dose range of 20 to 500 kGy. Degradation was observed both in solid and solution conditions. The degradation in solution was remarkably greater than that in solid. For example, the molecular weight of alginate in 4%(w/v) solution decreased from 2 x 10{sup 5} for 0 kGy to 6 x 10{sup 3} for 50 kGy irradiation while the equivalent degradation by solid irradiation required 500 kGy. The activated species from irradiated water must be responsible for the degradation in solution. The degradation was also accompanied with the color change of alginate: the color became deep brown for highly degraded alginate. UV spectra showed a distinct absorption peak at 265 nm for colored alginates, increasing with dose. The fact that discoloration of colored alginate was caused on exposure to ozone suggests a formation of double bond in pyranose-ring by scission of glycosidic bond. Degradation behavior of chitosan in irradiation was almost the same as that of alginate. (author)

  7. Degradation of chlorocarbons driven by hydrodynamic cavitation

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Z.L.; Ondruschka, B.; Braeutigam, P. [Institut fuer Technische Chemie und Umweltchemie, Friedrich-Schiller-Universitaet Jena, Jena (Germany)

    2007-05-15

    To provide an efficient lab-scale device for the investigation of the degradation of organic pollutants driven by hydrodynamic cavitation, the degradation kinetics of chloroform and carbon tetrachloride and the increase of conductivity in aqueous solutions were measured. These are values which were not previously available. Under hydrodynamic cavitation conditions, the degradation kinetics for chlorocarbons was found to be pseudo first-order. Meanwhile, C-H and C-Cl bonds are broken, and Cl{sub 2}, Cl{sup .}, Cl{sup -} and other ions released can increase the conductivity and enhance the oxidation of KI in aqueous solutions. The upstream pressures of the orifice plate, the cavitation number, and the solution temperature have substantial effects on the degradation kinetics. A decreased cavitation number can result in more cavitation events and enhances the degradation of chlorocarbons and/or the oxidation of KI. A decrease in temperature is generally favorable to the cavitation chemistry. Organic products from the degradation of carbon tetrachloride and chloroform have demonstrated the formation and recombination of free radicals, e.g., CCl{sub 4}, C{sub 2}Cl{sub 4}, and C{sub 2}Cl{sub 6} are produced from the degradation of CHCl{sub 3}. CHCl{sub 3} and C{sub 2}Cl{sub 6} are produced from the degradation of CCl{sub 4}. Both the chemical mechanism and the reaction kinetics of the degradation of chlorocarbons induced by hydrodynamic cavitation are consistent with those obtained from the acoustic cavitation. Therefore, the technology of hydrodynamic cavitation should be a good candidate for the removal of organic pollutants from water. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  8. Radiation degradation of short-cotton linters

    International Nuclear Information System (INIS)

    Ma Zue Teh; Zhou Rui Min

    1984-01-01

    Radiation degradation of short-cotton linters has been studied by using X-ray diffraction, an infrared spectrometer and a viscosimeter. Average molecular weight and crystallinity of short-cotton linters and the change of reducing sugar in γ-radiation degradation were examined. It was found that cellulosic saccharification in hydrolysis was enhanced with preirradiation of linter. This probably resulted from the radiation induced change of cellulosic structure. Sensitizers to promote radiation degradation effect were investigated. Carbon tetrachloride has been found to be effective. (author)

  9. Kinetic Parameters of Thermal Degradation of Polymers

    Institute of Scientific and Technical Information of China (English)

    朱新生; 程嘉祺

    2003-01-01

    The derivative expressions between activation energy (E) and the temperature at the maximum mass loss rate(Tmax) and between activation energy (E) and exponent (N) were deduced in the light of Arrhenius theory. It was found that the increase of activation energy results in the decrease of exponent and the increase of Tmax. The kinetic parameters were involved in the analysis of the thermal degradation of several polymers. The degradation kinetics of these polymers well complied with the prediction of the derivative expressions for the polymer degradation with single mechanism dominated.

  10. ANTI-BIOFOULING BY DEGRADATION OF POLYMERS

    Institute of Scientific and Technical Information of China (English)

    Chun-feng Ma; Hong-jun Yang; Guang-zhao Zhang

    2012-01-01

    Copolymers of methyl methacrylate (MMA) and acrylate terminated poly(ethylene oxide-co-ethylene carbonate)(PEOC) macromonomer (PEOCA) were synthesized,and the degradation of the polymers was investigated by use of quartz crystal microbalance with dissipation (QCM-D).It is shown that the polymeric surface exhibits degradation in seawater depending on the content of the side chains.Field tests in seawater show that the surface constructed by the copolymer can effectively inhibit marine biofouling because it can be self-renewed due to degradation of the copolymer.

  11. Radiation damage calculations for the LANSCE degrader

    International Nuclear Information System (INIS)

    Ferguson, P.D.; Sommer, W.F.; Dudziak, D.J.; Wechsler, M.S.; Barnett, M.H.; Corzine, R.K.

    1998-01-01

    The A-6 water degrader at the Los Alamos Neutron Science Center (LANSCE) linear proton accelerator has an outer shell of Inconel 718. The degrader was irradiated by 800-MeV protons during 1988--1993 to an exposure of 5.3 ampere-hours (A h). As described in Ref. 1, material from the Inconel is currently being cut into specimens for microhardness, three-point bending, ball punch, microscopy, and corrosion tests. This paper is devoted to calculations of radiation damage, particularly displacement and He production, sustained by the degrader Inconel

  12. Autonomous valve for detection of biopolymer degradation

    DEFF Research Database (Denmark)

    Keller, Stephan Urs; Noeth, Nadine-Nicole; Fetz, Stefanie

    2009-01-01

    We present a polymer microvalve that allows the detection of biopolymer degradation without the need of external energy. The valve is based on a polymer container filled with a colored marker solution and closed by a thin lid. This structure is covered by a film of poly(L-lactide) and degradation...... of the biopolymer triggers the release of the color which is detected visually. The autonomous valve has potential for the fast testing of biopolymer degradation under various environmental conditions or by specific enzymes....

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

    Science.gov (United States)

    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.

  14. Method of degrading pollutants in soil

    Science.gov (United States)

    Hazen, Terry C.; Lopez-De-Victoria, Geralyne

    1994-01-01

    A method and system for enhancing the motility of microorganisms by placing an effective amount of chlorinated hydrocarbons, preferably chlorinated alkenes, and most preferably trichloroethylene in spaced relation to the microbes so that the surprisingly strong, monomodal, chemotactic response of the chlorinated hydrocarbon on subsurface microbes can draw the microbes away from or towards and into a substance, as desired. In remediation of groundwater pollution, for example, TCE can be injected into the plume to increase the population of microbes at the plume whereby the plume can be more quickly degraded. A TCE-degrading microbe, such as Welchia alkenophilia, can be used to degrade the TCE following the degradation of the original pollutant.

  15. Bacterial degradation of monocyclic aromatic amines

    Directory of Open Access Journals (Sweden)

    Pankaj Kumar Arora

    2015-08-01

    Full Text Available Aromatic amines are an important group of industrial chemicals, which are widely used for manufacturing of dyes, pesticides, drugs, pigments, and other industrial products. These compounds have been considered highly toxic to human beings due to their carcinogenic nature. Three groups of aromatic amines have been recognized: monocyclic, polycyclic and heterocyclic aromatic amines. Bacterial degradation of several monocyclic aromatic compounds has been studied in a variety of bacteria, which utilizes monocyclic aromatic amines as their sole source of carbon and energy. Several degradation pathways have been proposed and the related enzymes and genes have also been characterized. Many reviews have been reviewed toxicity of monocyclic aromatic amines; however, there is lack of review on biodegradation of monocyclic aromatic amines. The aim of this review is to summarize bacterial degradation of monocyclic aromatic amines. This review will increase our current understanding of biochemical and molecular basis of bacterial degradation of monocyclic aromatic amines.

  16. Plant Wall Degradative Compounds and Systems

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The present invention relates to cell wall degradative systems, in particular to systems containing enzymes that bind to and/or depolymerize cellulose. These systems...

  17. Polymer Composites Corrosive Degradation: A Computational Simulation

    Science.gov (United States)

    Chamis, Christos C.; Minnetyan, Levon

    2007-01-01

    A computational simulation of polymer composites corrosive durability is presented. The corrosive environment is assumed to manage the polymer composite degradation on a ply-by-ply basis. The degradation is correlated with a measured pH factor and is represented by voids, temperature and moisture which vary parabolically for voids and linearly for temperature and moisture through the laminate thickness. The simulation is performed by a computational composite mechanics computer code which includes micro, macro, combined stress failure and laminate theories. This accounts for starting the simulation from constitutive material properties and up to the laminate scale which exposes the laminate to the corrosive environment. Results obtained for one laminate indicate that the ply-by-ply degradation degrades the laminate to the last one or the last several plies. Results also demonstrate that the simulation is applicable to other polymer composite systems as well.

  18. Stability and Degradation of Polymer Solar cells

    DEFF Research Database (Denmark)

    Norrman, Kion

    The current state-of-the-art allows for roll-to-roll manufacture of polymer solar cells in high volume with stability and efficiency sufficient to grant success in low-energy applications. However, further improvement is needed for the successful application of the devices in real life applications....... This is obtained by detailed knowledge of the degradation mechanisms. Methods to compare and standardize device stability are urgently needed. Methodologies to study failure mechanism that are based on physical processes (e.g. morphological changes) are well-established. However, methodologies to study chemical...... degradation mechanisms are currently scarce. An overview of known degradation mechanisms will be presented and discussed in relation to state-of-the-art methodologies to study failure mechanisms with focus on chemical degradation....

  19. Degradation Behavior of Thermal Stabilized Polyacrylonitrile Fibers

    Directory of Open Access Journals (Sweden)

    LEI Shuai

    2017-05-01

    Full Text Available In the temperature range of 300-800℃, 40%-50% of the mass lost during the processing of polyacrylonitrile based carbon fiber (PANCF. Understanding the degradation behavior will be valuable in understanding the formation mechanism of pseudo-graphite structure, and providing theoretic basis for producing high performance carbon fiber and increasing the carbonization yield. The simulation of the degradation progress was carried out on the thermogravimetric analyzer (TGA, the results show that there are two degradation steps for PAN fiber stabilized in air, and controlled by cyclization coefficient and oxygen content. The cyclization coefficient and oxygen content are effective to the density of carbon fiber by influencing the degradation behavior, which cause defects in the fiber. The higher cyclization coefficient leads to form less structural defects and higher density of the fiber; on the contrary, the higher oxygen content leads to form more structural defects and lower density of the fiber.

  20. Degradation characteristics of waste polyurethane by radiation

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jong Seok; Ahn, Sung Jun; Gwon Hui Jeong; Jeong, Sung In; Nho, Young Chang; Lim, Youn Mook [Research Division for Industry and Environment, Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

    2017-06-15

    Polyurethane (PU) is a very popular polymer that is used in a variety of applications due to its good mechanical, thermal, and chemical properties. However, waste PU recycling has received significant attention due to environmental issues. The aim of this work was to investigate the degradation characteristics of waste PU to recycle. Degradation of waste PU was carried out using a radiation techniques. Waste PUs were exposed to a gamma {sup 60}Co sources. To verify degradation, the irradiated PUs were characterized using FT-IR, gel permeation chromatography (GPC), and their thermal/mechanical properties are reported. When the radiation dose was 500 kGy, the molecular weight of the waste PU drastically decreased. Also, the mechanical properties of waste PU were approximately 4 times lower than those of non-irradiated PU. This study has confirmed the possibility of making fine particle of waste PU for recycling through radiation degradation techniques.

  1. Degradation mechanisms of small scale piping systems

    International Nuclear Information System (INIS)

    Bartonicek, J.; Koenig, G.; Blind, D.

    1996-01-01

    Operational experience shows that many degradation mechanisms can have an effect on small-scale piping systems. We can see from the analyses carried out that the degradation which has occurred is primarily linked with the fact that these piping systems were classified as being of low safety relevance. This is mainly due to such components being classified into low safety relevance category at the design stage, as well as to the low level of operational monitoring. Since in spite of the variety of designs and operational modes the degradation mechanisms detected may be attributed to the piping systems, we can make decisive statements on how to avoid such degradation mechanisms. Even small-scale piping systems may achieve guaranteed integrity in such cases by taking the appropriate action. (orig.) [de

  2. ESR studies on degradation processes in polyethyleneterephtalate

    International Nuclear Information System (INIS)

    Chipara, M.; Chipara, M.D.; Georgescu, L.; Constantinescu, L.; Morosanu, C.

    2002-01-01

    Complete text of publication follows. The generation of free radicals by degradation processes (thermal, plasma and radiation induced) is analyzed. Details regarding the generation of free radicals, their interactions, and kinetics, as revealed by electron spin resonance (ESR), with emphasis on laser beam degradation, are discussed. Some ESR lines of laser-irradiated polyethyleneterephtalate (PET), recorded at room temperature, are shown in Figure 1. The lines are narrow singlets located around g=2.003. The resonance line amplitude, width and double integral of the resonance line are affected by the power of the incident beam. The common features of these degradation processes (universal behavior) as well as the fingerprints of each degradation process are analyzed in detail

  3. Aggradation, Degradation, and Water Quality Conditions

    National Research Council Canada - National Science Library

    1993-01-01

    The purpose of this study is to compile a record of pertinent data and information relative to aggradation, degradation, and water quality within the system of six Missouri River mainstem reservoirs...

  4. Degradation of crude oil by marine cyanobacteria

    Digital Repository Service at National Institute of Oceanography (India)

    Raghukumar, C.; Vipparty, V.; David, J.J.; Chandramohan, D.

    The marine cyanobacteria Oscillatoria salina Biswas, Plectonema terebrans Bornet et Flanhault and Aphanocapsa sp. degraded Bombay High crude oil when grown in artificial seawater nutrients as well as in plain natural seawater. Oil removals...

  5. Hot carrier degradation in semiconductor devices

    CERN Document Server

    2015-01-01

    This book provides readers with a variety of tools to address the challenges posed by hot carrier degradation, one of today’s most complicated reliability issues in semiconductor devices.  Coverage includes an explanation of carrier transport within devices and book-keeping of how they acquire energy (“become hot”), interaction of an ensemble of colder and hotter carriers with defect precursors, which eventually leads to the creation of a defect, and a description of how these defects interact with the device, degrading its performance. • Describes the intricacies of hot carrier degradation in modern semiconductor technologies; • Covers the entire hot carrier degradation phenomenon, including topics such as characterization, carrier transport, carrier-defect interaction, technological impact, circuit impact, etc.; • Enables detailed understanding of carrier transport, interaction of the carrier ensemble with the defect precursors, and an accurate assessment of how the newly created defects imp...

  6. Degradation of magnetite nanoparticles in biomimetic media

    Energy Technology Data Exchange (ETDEWEB)

    Briceño, Sarah; Hernandez, Ana C.; Sojo, Juan [Instituto Venezolano de Investigaciones Científicas (IVIC), Laboratorio de Materiales, Centro de Ingeniería de Materiales y Nanotecnología (Venezuela, Bolivarian Republic of); Lascano, Luis [Dpto. Física, Escuela Politécnica Nacional (Ecuador); Gonzalez, Gema, E-mail: gemagonz@ivic.gob.ve, E-mail: gema.gonzalez@epn.edu.ec [Escuela Nacional Politécnica (Ecuador)

    2017-04-15

    Magnetic nanoparticles (NPs) of magnetite Fe{sub 3}O{sub 4} obtained by coprecipitation (COP), thermal decomposition (DT), and commercial sample (CM) have been degraded in similar conditions to physiological medium at pH 4.7 and in simulated body fluid (SBF) at pH 7.4. The formation of the nanoparticles was confirmed by FTIR spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). In view of medical and environmental applications, the stability of the particles was measured with dynamic light scattering. The degradation processes were followed with atomic absorption spectroscopy (EAA) and TEM. Magnetic measurements were carried out using vibrating sample magnetometry (VSM). Our results revealed that the structural and magnetic properties of the remaining nanoparticles after the degradation process were significantly different to those of the initial suspension. The degradation kinetics is affected by the pH, the coating, and the average particle size of the nanoparticles.

  7. PHOTOCATALYTIC DEGRADATION OF CRYSTAL VIOLET BY ...

    African Journals Online (AJOL)

    In recent years, removal of undesirable organic contaminants from water and wastewater is ... accidental leakage of tanks containing pollutants, etc. ..... Consideration of reaction pathways and degradation rates is critical for detection of waste.

  8. Phytohormone and Light Regulation of Chlorophyll Degradation

    Directory of Open Access Journals (Sweden)

    Xiaoyu Zhu

    2017-11-01

    Full Text Available Degreening, due to the net loss of chlorophyll (Chl, is the most prominent symptom during the processes of leaf senescence, fruit ripening, and seed maturation. Over the last decade or so, extensive identifications of Chl catabolic genes (CCGs have led to the revelation of the biochemical pathway of Chl degradation. As such, exploration of the regulatory mechanism of the degreening process is greatly facilitated. During the past few years, substantial progress has been made in elucidating the regulation of Chl degradation, particularly via the mediation of major phytohormones' signaling. Intriguingly, ethylene and abscisic acid's signaling have been demonstrated to interweave with light signaling in mediating the regulation of Chl degradation. In this review, we briefly summarize this progress, with an effort on providing a framework for further investigation of multifaceted and hierarchical regulations of Chl degradation.

  9. Concrete performance using low-degradation aggregates.

    Science.gov (United States)

    2012-06-01

    The durability of Portland cement concrete (PCC) has long been identified as a concern by transportation communities around the United States. In this study, the long-term performance of two batches of concrete incorporating either low-degradation (L...

  10. Implications for Forest Resource Degradation and Deforestation ...

    African Journals Online (AJOL)

    Effects of Socio-Economic Status and Food Consumption Pattern on Household Energy uses: Implications for Forest Resource Degradation and Deforestation around Wondo Genet Catchments, South-Central Ethiopia.

  11. Polycyclic aromatic hydrocarbons (PAHs) degradation by laccase ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-11-02

    Nov 2, 2009 ... Full Length Research Paper. Polycyclic aromatic ... production of paper, feeds, chemicals and fuels there is ... microbes with the production of lignin-modifying enzymes ... enable white rot fungi to degrade a variety of toxic.

  12. Method of degrading pollutants in soil

    Science.gov (United States)

    Hazen, T.C.; Lopez-De-Victoria, G.

    1994-07-05

    Disclosed are a method and system for enhancing the motility of microorganisms. This is accomplished by placing an effective amount of chlorinated hydrocarbons, preferably chlorinated alkenes, and most preferably trichloroethylene in spaced relation to the microbes so that the surprisingly strong, monomodal, chemotactic response of the chlorinated hydrocarbon on subsurface microbes can draw the microbes away from or towards and into a substance, as desired. In remediation of groundwater pollution, for example, TCE can be injected into the plume to increase the population of microbes at the plume whereby the plume can be more quickly degraded. A TCE-degrading microbe, such as Welchia alkenophilia, can be used to degrade the TCE following the degradation of the original pollutant. 5 figures.

  13. Degradation of Waterfront Reinforced Concrete Structures

    African Journals Online (AJOL)

    Key words: Degradation, reinforced concrete, Dar es Salaam port. Abstract—One of the ... especially corrosion of the reinforcement. ... Corrosion of steel reinforcement contributes .... cracks along the line of reinforcement bars and most of the ...

  14. Modelling sulfamethoxazole degradation under different redox conditions

    Science.gov (United States)

    Sanchez-Vila, X.; Rodriguez-Escales, P.

    2015-12-01

    Sulfamethoxazole (SMX) is a low adsorptive, polar, sulfonamide antibiotic, widely present in aquatic environments. Degradation of SMX in subsurface porous media is spatially and temporally variable, depending on various environmental factors such as in situ redox potential, availability of nutrients, local soil characteristics, and temperature. It has been reported that SMX is better degraded under anoxic conditions and by co-metabolism processes. In this work, we first develop a conceptual model of degradation of SMX under different redox conditions (denitrification and iron reducing conditions), and second, we construct a mathematical model that allows reproducing different experiments of SMX degradation reported in the literature. The conceptual model focuses on the molecular behavior and contemplates the formation of different metabolites. The model was validated using the experimental data from Barbieri et al. (2012) and Mohatt et al. (2011). It adequately reproduces the reversible degradation of SMX under the presence of nitrite as an intermediate product of denitrification. In those experiments degradation was mediated by the transient formation of a diazonium cation, which was considered responsible of the substitution of the amine radical by a nitro radical, forming the 4-nitro-SMX. The formation of this metabolite is a reversible process, so that once the concentration of nitrite was back to zero due to further advancement of denitrification, the concentration of SMX was fully recovered. The forward reaction, formation of 4-nitro SMX, was modeled considering a kinetic of second order, whereas the backward reaction, dissociation of 4-nitro-SMX back to the original compound, could be modeled with a first order degradation reaction. Regarding the iron conditions, SMX was degraded due to the oxidation of iron (Fe2+), which was previously oxidized from goethite due to the degradation of a pool of labile organic carbon. As the oxidation of iron occurred on the

  15. Degradation of hop bitter acids by fungi

    International Nuclear Information System (INIS)

    Huszcza, Ewa; Bartmanska, Agnieszka; Aniol, Miroslaw; Maczka, Wanda; Zolnierczyk, Anna; Wawrzenczyk, Czeslaw

    2008-01-01

    Nine fungal strains related to: Trametes versicolor, Nigrospora oryzae, Inonotus radiatus, Crumenulopsis sororia, Coryneum betulinum, Cryptosporiopsis radicicola, Fusarium equiseti, Rhodotorula glutinis and Candida parapsilosis were tested for their ability to degrade humulones and lupulones. The best results were obtained for T. versicolor culture, in which humulones and lupulones were fully degraded after 4 days of incubation in the dark or after 36 h in the light. The experiments were performed on a commercial hop extract and on sterilized spent hops

  16. Increased radiation degradation in methyl methacrylate copolymers

    International Nuclear Information System (INIS)

    Helbert, J.N; Wagner, G.E.; Caplan, P.J.; Poindexter, E.H.

    1975-01-01

    The effect of polar substituents at the quaternary carbon on degradation processes in several polymers and 10 to 20 percent copolymers of methyl methacrylate was explored. EPR was used to monitor radiation degradation products and to determine radiation G values. Irradiations were carried out at 77 0 K in a gamma irradiator at a dose rate of 0.3 Mrad/hr. (U.S.)

  17. Accelerated Testing Of Photothermal Degradation Of Polymers

    Science.gov (United States)

    Kim, Soon Sam; Liang, Ranty Hing; Tsay, Fun-Dow

    1989-01-01

    Electron-spin-resonance (ESR) spectroscopy and Arrhenius plots used to determine maximum safe temperature for accelerated testing of photothermal degradation of polymers. Aging accelerated by increasing illumination, temperature, or both. Results of aging tests at temperatures higher than those encountered in normal use valid as long as mechanism of degradation same throughout range of temperatures. Transition between different mechanisms at some temperature identified via transition between activation energies, manifesting itself as change in slope of Arrhenius plot at that temperature.

  18. Photochemical degradation of alachlor in water

    Directory of Open Access Journals (Sweden)

    Tajana Đurkić

    2017-01-01

    Full Text Available This study investigates the photochemical degradation of alachlor, a chloroacetanilide herbicide. All experiments were conducted in ultra-pure deionized water (ASTM Type I quality using direct ultraviolet (UV photolysis and the UV/H2O2 advanced oxidation process. The direct UV photolysis and UV/H2O2 experiments were conducted in a commercial photochemical reactor with a quartz reaction vessel equipped with a 253.7 nm UV low pressure mercury lamp (Philips TUV 16 W. The experimental results demonstrate that UV photolysis was very effective for alachlor degradation (up to 97% removal using a high UV fluence of 4200 mJ/cm2. The UV/H2O2 process promoted alachlor degradation compared to UV photolysis alone, with a high degree of decomposition (97% achieved at a significantly lower UV fluence of 600 mJ/cm2 when combined with 1 mg H2O2/L. The application of UV photolysis alone with a UV fluence of 600 mJ/cm2 gave a negligible 4% alachlor degradation. The photo degradation of alachlor, in both direct UV photolysis and the UV/H2O2 process, followed pseudo first-order kinetics. The degradation rate constant was about 6 times higher for the UV/H2O2 process than for UV photolysis alone.

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

    Science.gov (United States)

    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.

  20. 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...

  1. Degradation of morpholine by Mycobacterium sp. isolated from ...

    African Journals Online (AJOL)

    Jane

    2011-08-08

    Aug 8, 2011 ... Full Length Research Paper. Degradation ... The heterocyclic xenobiotic compound morpholine (1- ... Culture of morpholine degrading microorganisms ..... Biodegradation and toxicity of selected amines on aquatic organisms.

  2. 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.

  3. Nanobiocatalytic Degradation of Acid Orange 7

    Science.gov (United States)

    Hastings, Jason

    The catalytic properties of various metal nanoparticles have led to their use in environmental remediation applications. However, these remediation strategies are limited by their ability to deliver catalytic nanoparticles and a suitable electron donor to large treatment zones. Clostridium pasteurianum BC1 cells, loaded with bio-Pd nanoparticles, were used to effectively catalyze the reductive degradation and removal of Acid Orange 7 (AO7), a model azo compound. Hydrogen produced fermentatively by the C. pasteurianum BC1 acted as the electron donor for the process. Pd-free bacterial cultures or control experiments conducted with heat-killed cells showed limited reduction of AO7. Experiments also showed that the in situ biological production of H2 by C. pasteurianum BC1 was essential for the degradation of AO7, which suggests a novel process where the in situ microbial production of hydrogen is directly coupled to the catalytic bio-Pd mediated reduction of AO7. The differences in initial degradation rate for experiments conducted using catalyst concentrations of 1ppm Pd and 5ppm Pd and an azo dye concentration of 100ppm AO7 was 0.39 /hr and 1.94 /hr respectively, demonstrating the importance of higher concentrations of active Pd(0). The degradation of AO7 was quick as demonstrated by complete reductive degradation of 50ppm AO7 in 2 hours in experiments conducted using a catalyst concentration of 5ppm Pd. Dye degradation products were analyzed via Gas Chromatograph-Mass Spectrometer (GCMS), High Performance Liquid Chromatography (HPLC), UltraViolet-Visible spectrophotometer (UV-Vis) and Matrix-Assisted Laser Desorption/Ionization (MALDI) spectrometry. The presence of 1-amino 2-naphthol, one of the hypothesized degradation products, was confirmed using mass spectrometry.

  4. Mineral induced mechanochemical degradation: the imazaquin case.

    Science.gov (United States)

    Nasser, Ahmed; Buchanovsky, Nadia; Gerstl, Zev; Mingelgrin, Uri

    2009-03-01

    The potential role of mechanochemical processes in enhancing degradation of imazaquin by soil components is demonstrated. The investigated components include montmorillonite saturated with Na(+), Ca(2+), Cu(2+)and Al(3+), Agsorb (a commercial clay mix), birnessite and hematite. The mechanical force applied was manual grinding of mixtures of imazaquin and the minerals, using mortar and pestle. The degradation rates of imazaquin in these mixtures were examined as a function of the following parameters: time of grinding, herbicide load (3.9, 8.9, 16.7 and 26.6 mg imazaquin per g mineral), temperature (10, 25, 40 and 70 degrees C), acidic/basic conditions, and dry or wet grinding. Dry grinding of imazaquin for 5 min with Al-montmorillonite or with hematite resulted in 56% and 71% degradation of the imazaquin, respectively. Wet grinding slightly reduced the degradation rate with hematite and entirely cancelled the enhancing effect of grinding with Al-montmorillonite. Wet grinding in the presence of the transition metals: Ni(2+), Cu(2+), Fe(3+) added as chlorides was carried out. Addition of Cu(2+) to Na-montmorillonite loaded with imazaquin was the most effective treatment in degrading imazaquin (more than 90% of the imazaquin degraded after 5 min of grinding). In this treatment, Cu-montmorillonite formation during the grinding process was confirmed by XRD and accordingly, grinding with Cu-montmorillonite gave similar degradation values. LC-MS analysis revealed that the mechanochemical transformation of imazaquin resulted in the formation of a dimer and several breakdown products. The reported results demonstrate once again that mechanochemical procedures offer a remediation avenue applicable to soils polluted with organic contaminants.

  5. Crater Degradation on Mercury: A Global Perspective

    Science.gov (United States)

    Kinczyk, M. J.; Byrne, P. K.; Prockter, L. M.; Susorney, H. C. M.; Chapman, C. R.; Barnouin, O. S.

    2017-12-01

    On geologic timescales, initially fresh craters are subjected to many weathering mechanisms. Whereas water and wind are, or were, effective erosive mechanisms such as on Earth and Mars, micrometeorite bombardment and modification due to subsequent impacts are the dominant processes that degrade craters and crater rays on airless bodies like the Moon and Mercury. Classifying craters based on their state of degradation can help determine the relative ages of landforms proximal to, and crosscut by, these craters. However, this method is most effective when used together with statistical analysis of crater distributions. Pre-MESSENGER degradation classification schemes lacked sufficient detail to be consistently applied to craters of various sizes and morphological types—despite evidence suggesting that the ejecta deposits of large basins persist much longer than those of smaller craters, for instance—yet broad assumptions have been made regarding the correlation of crater class to the planet's time-stratigraphic sequence. Moreover, previous efforts to categorize craters by degradation state have either been restricted to regional study sites or applied only to a subset of crater age or size. As a result, numerous interpretations of crater degradation state persist for Mercury, challenging a complete understanding of this process on the innermost planet. We report on the first global survey of crater degradation on Mercury. By modifying an established 5-class scheme, we have systematically applied a rigorous set of criteria to all craters ≥40 km in diameter on the planet. These criteria include the state and morphology of crater deposits separately (e.g., rim, floor, wall, ejecta) and degradation classes were assigned as the collection of these individual attributes. This approach yields a consistent classification of craters of different sizes. Our results provide the first comprehensive assessment of how craters of various states of degradation are distributed

  6. Self-degradable Cementitious Sealing Materials

    Energy Technology Data Exchange (ETDEWEB)

    Sugama, T.; Butcher, T., Lance Brothers, Bour, D.

    2010-10-01

    A self-degradable alkali-activated cementitious material consisting of a sodium silicate activator, slag, Class C fly ash, and sodium carboxymethyl cellulose (CMC) additive was formulated as one dry mix component, and we evaluated its potential in laboratory for use as a temporary sealing material for Enhanced Geothermal System (EGS) wells. The self-degradation of alkali-activated cementitious material (AACM) occurred, when AACM heated at temperatures of {ge}200 C came in contact with water. We interpreted the mechanism of this water-initiated self-degradation as resulting from the in-situ exothermic reactions between the reactants yielded from the dissolution of the non-reacted or partially reacted sodium silicate activator and the thermal degradation of the CMC. The magnitude of self-degradation depended on the CMC content; its effective content in promoting degradation was {ge}0.7%. In contrast, no self-degradation was observed from CMC-modified Class G well cement. For 200 C-autoclaved AACMs without CMC, followed by heating at temperatures up to 300 C, they had a compressive strength ranging from 5982 to 4945 psi, which is {approx}3.5-fold higher than that of the commercial Class G well cement; the initial- and final-setting times of this AACM slurry at 85 C were {approx}60 and {approx}90 min. Two well-formed crystalline hydration phases, 1.1 nm tobermorite and calcium silicate hydrate (I), were responsible for developing this excellent high compressive strength. Although CMC is an attractive, as a degradation-promoting additive, its addition to both the AACM and the Class G well cement altered some properties of original cementitious materials; among those were an extending their setting times, an increasing their porosity, and lowering their compressive strength. Nevertheless, a 0.7% CMC-modified AACM as self-degradable cementitious material displayed the following properties before its breakdown by water; {approx}120 min initial- and {approx}180 min final

  7. Fontes suplementares de proteína para novilhos mestiços em recria em pastagens de capim-braquiária no período das águas: desempenho produtivo e econômico Protein sources in multiple supplements for finishing crossbred steers on Brachiaria pasture, in the wet season: productive and economical performance

    Directory of Open Access Journals (Sweden)

    Marlos Oliveira Porto

    2009-08-01

    Full Text Available Avaliou-se o desempenho de novilhos mestiços Holandês-Zebu em fase de recria recebendo suplementação com fontes de proteína em uma área de pastagem de Brachiaria brizantha, cv. Marandu, durante o período das águas. A área foi dividida em piquetes de 1,5 ha, com disponibilidade média de matéria seca e matéria seca potencialmente digestível de 7,46 e 4,50 t/ha, respectivamente. Utilizaram-se 25 novilhos mestiços com peso e idade iniciais médios de 229 kg e 12 meses, distribuídos em delineamento inteiramente casualizado, com cinco fontes de proteína e cinco repetições. As fontes de proteína testadas foram mistura mineral - grupo controle (60 g/animal; farelo de soja + farelo de algodão + mistura mineral (510 g/animal; farelo de soja + mistura mineral (460 g/animal; grão de soja triturado e mistura mineral (560 g/animal; grão de soja inteiro e mistura mineral (560 g/animal. Embora sem significância estatística, os animais que receberam suplemento múltiplo apresentaram ganho médio diário de 211 g/animal (23,78% a mais que aqueles que receberam somente mistura mineral. O uso do suplemento múltiplo à base de farelo de soja e farelo de algodão proporcionou aumento numérico de 247 g/animal em relação à mistura mineral. A suplementação com as fontes de proteína pode proporcionar ganhos adicionais durante o período das águas. A suplementação múltipla proporcionou retorno econômico, indiferentemente da fonte de proteína utilizada.The performance was evaluated of beef crossbred Holstein-Zebu steers, supplemented with different protein sources on pasture of Brachiaria brizantha, cv. Marandu, during the wet season. The area was divided into paddocks of 1.5 ha, with an availability of dry matter and potentially digestible dry matter of 7.46 and 4.50 t/ha, respectively. Twenty-five animals with 229 kg initial weight and 12 months of age were distributed in a complete randomized design, with five treatments and five

  8. Phenomenology of BWR fuel assembly degradation

    Science.gov (United States)

    Kurata, Masaki; Barrachin, Marc; Haste, Tim; Steinbrueck, Martin

    2018-03-01

    Severe accidents occurred at the Fukushima-Daiichi Nuclear Power Station (FDNPS) which required an immediate re-examination of fuel degradation phenomenology. The present paper reviews the updated knowledge on the phenomenology of the fuel degradation, focusing mainly on the BWR fuel assembly degradation at the macroscopic scale and that of the individual interactions at the meso-scale. Oxidation of boron carbide (B4C) control rods potentially generates far larger amounts of heat and hydrogen under BWR accident conditions. All integral tests with B4C control rods or control blades have shown early failure, liquefaction, relocation and oxidation of B4C starting at temperatures around 1250 °C, well below the significant interaction temperatures of UO2-Zry. These interactions or reactions potentially influence the progress of fuel degradation in the early phase. The steam-starved conditions, which are being discussed as a likely scenario at the FDNPS accident, highly influence the individual interactions and potentially lead the fuel degradation in non-prototypical directions. The detailed phenomenology of individual interactions and their influence on the transient and on the late phase of the severe accidents are also discussed.

  9. Modeling the degradation kinetics of ascorbic acid.

    Science.gov (United States)

    Peleg, Micha; Normand, Mark D; Dixon, William R; Goulette, Timothy R

    2018-06-13

    Most published reports on ascorbic acid (AA) degradation during food storage and heat preservation suggest that it follows first-order kinetics. Deviations from this pattern include Weibullian decay, and exponential drop approaching finite nonzero retention. Almost invariably, the degradation rate constant's temperature-dependence followed the Arrhenius equation, and hence the simpler exponential model too. A formula and freely downloadable interactive Wolfram Demonstration to convert the Arrhenius model's energy of activation, E a , to the exponential model's c parameter, or vice versa, are provided. The AA's isothermal and non-isothermal degradation can be simulated with freely downloadable interactive Wolfram Demonstrations in which the model's parameters can be entered and modified by moving sliders on the screen. Where the degradation is known a priori to follow first or other fixed order kinetics, one can use the endpoints method, and in principle the successive points method too, to estimate the reaction's kinetic parameters from considerably fewer AA concentration determinations than in the traditional manner. Freeware to do the calculations by either method has been recently made available on the Internet. Once obtained in this way, the kinetic parameters can be used to reconstruct the entire degradation curves and predict those at different temperature profiles, isothermal or dynamic. Comparison of the predicted concentration ratios with experimental ones offers a way to validate or refute the kinetic model and the assumptions on which it is based.

  10. Degradable polymeric materials for osteosynthesis: Tutorial

    Directory of Open Access Journals (Sweden)

    D Eglin

    2008-12-01

    Full Text Available This report summarizes the state of the art and recent developments and advances in the use of degradable polymers devices for osteosynthesis. The current generation of biodegradable polymeric implants for bone repair utilising designs copied from metal implants, originates from the concept that devices should be supportive and as “inert” substitute to bone tissue. Today degradable polymeric devices for osteosynthesis are successful in low or mild load bearing applications. However, the lack of carefully controlled randomized prospective trials that document their efficacy in treating a particular fracture pattern is still an issue. Then, the choice between degradable and non-degradable devices must be carefully weighed and depends on many factors such as the patient age and condition, the type of fracture, the risk of infection, etc. The improvement of the biodegradable devices mechanical properties and their degradation behaviour will have to be achieved to broaden their use. The next generation of biodegradable implants will probably see the implementation of the recent gained knowledge in cell-material interactions and cells therapy, with a better control of the spatial and temporal interfaces between the material and the surrounding bone tissue.

  11. Degradation of chlorpyrifos in tropical rice soils.

    Science.gov (United States)

    Das, Subhasis; Adhya, Tapan K

    2015-04-01

    Chlorpyrifos [O,O-diethyl O-(3,5,6-trichloro-2-pyridinol) phosphorothioate] is used worldwide as an agricultural insecticide against a broad spectrum of insect pests of economically important crops including rice, and soil application to control termites. The insecticide mostly undergoes hydrolysis to diethyl thiophosphoric acid (DETP) and 3,5,6-trichloro-2-pyridinol (TCP), and negligible amounts of other intermediate products. In