Effect on of in vitro fermentation of mixture of Tithonia diversifolia, Cenchrus clandestinum and polyunsaturated fats

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Juan Leonardo Cardona Iglesias

2017-04-01

Full Text Available The aim of this study was evaluated by in vitro, the effect of mixing wild sunflower (Tithonia diversifolia, kikuyu (Cenchrus clandestinum and concentrated feed, with the addition of polyunsaturated fatty acids (AGPI on the production of methane (CH4 ml/g MSd, dry matter digestibility (%DIVMS and production of volatile fatty acids (AGV. The research was conducted in NUTRILAB laboratory (Medellin, Colombia in September 2015. Three combinations of AGPI rich lipid sources were used with a total maximum inclusion level corresponding to 3% of incubated dry matter. Combinations of lipid sources were: SAGPI1: 0.5% soya oil, 0.5% sish oil, 2% rich in omega 3 bypass fat. SAGPI2: 1% Soya oil, 0.5% fish oil, 1.5% bypass fat rich in omega 3. SAGPI3: 2.5% Soya oil, 0.5% fish oil. A source of bypass fat (GSP was also used. The results were processed using pre-planned test comparisons through the PROC MIXED-SAS.The methane production in vitro decreased (p<0.05, while the dry matter digestibility increased (p<0.05 24 and 48 hours after wild sunflower was include and / or AGPI or both into the mixtures. In the molar ratio of AGV (%, acetic acid showed an increased presence. The inclusion of forage like wild sunflower and sources of AGPI supplementation in cattle, could be a strategy to reduce methane emissions without causing a detriment to the ruminal fermentation.

Ciclo de vida, estruturas reprodutivas e dispersão de populações experimentais de capim-carrapicho (Cenchrus echinatus L. Life cycle, reproductive structures and dispersion of experimental populations of sandbur (Cenchrus ech inatus L.

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R.P. de B. Pacheco

1984-06-01

Full Text Available A partir de semeaduras mensais de 500 cariopses em áreas de 5,00 x 3,80 m em sulcos distanciados de um metro e com profundidade de 3 cm foram obtidas 12 populações experimentais. Após 20 dias foram feitos desbastes nos canteiros restando 120 plantas distanciadas de 20 cm nas linhas. A cada mês foram coletadas ao acaso, 10 plantas para a contagem das estruturas reprodutivas. Considerando-se as quantidades de racemos, de fascículos e de cariopses, épocas de florescimento, tempo de dispersão e duração do ciclo de vida foi possível distinguir quatro periodos de semeadura. O primeiro de novembro a janeiro caracterizado pela quantidade de racemos e de fascículos bem maior que a dos outros períodos, cerca de 70% do total geral e também pela maior quantidade de cariopses. O início do florescimento foi o mais precoce (2.° mês a dispersão de fascículos durante 120 dias com os maiores ID (72% e 210 dias de duração do ciclo de vida. O segundo de fevereiro a março caracterizado pela menor quantidade de race-mos, de fascículos e de cariopses (2% do total geral. O início do florescimento foi tardio (4.° mês; dispersão de fascículos durante 60 dias e o menor ID (44%; 180 e 150 dias, respectivamente, de duração do ciclo de vida. O 3.° período de abril a julho, caracterizado por quantidade pequena de racemos (19% do total geral e quantidade intermediária de fascículos e cariopses (cerca de 21% do total geral. O início do florescimento foi tardio (4.° mês; dispersão de fascículos durante 60 dias (para as de abril e 90 dias (para as de maio, junho e julho, ID (70% e 210 dias de duração do ciclo de vida. 0 4.° período de agosto a outubro, caracterizado por quantidade muito pequena de race-mos, de fascículos e de cariopses (7% do total geral. 0 início do florescimento ocorreu no 3.° mês; dispersão de fascículos durante 60 dias, ID (47% e 150 dias (agosto e 120 dias (setembro e outubro de duração do ciclo.Twelve experimental populations were obtained by making monthly so wings in 3 cm deep de pressions spaced one meter a part in 5,00 x 3,80 m plots. After 20 days the plots were thinned to leave 120 plants 20 cm apart. Each month 10 plant s were randomly harvested and the reproductive structures counted. Four sowing periods wer e distinguishab le based on the number of racemes, fascicles and ca ryopse s produced , the time of initiation of flowering, duration of fascicle dispersal and life cycle length. The first period includes so wings made in the months of november to january and is characterized by the highest production of racemes and fascicles, about 70% of the total, as well as the greatest production of caryopses. Also, the initiation of flowering was th e most precocious (2 nd month, the period of fascicle dispersal the longest (210 days, the dispersal index the highest (72% and the life cycle long (210 days. The second period includ es sowings made in Februa ry and March and is characterized by the lowest production of racemes, fas cicles and caryopses (2% of the total . Initiation of flowering was late (4 th month . Fascicle dispersal ocurred during 60 days and the dispersal index was the lowest observed (44%. Life cycle length was 180 and 150 da ys re spectively fo r the January and February sowings. The third period includes April to June and was characterized by low raceme production (19% of the total and intermediate production of fa sc ic le s an d ca ryopse s (about 21% of the total. The initiation of flowering was retarded (4th month, fascicle dispersal lasted 60 days for the April sowing and 90 days for the sowings of May, June and July. The dispersal index was 70% and life cycle length was 210 days. The fourth period, sowings of August and October, was characterized by very low production of racemes, fascicles and caryopses (7% of the total. Flowering was initiation in the third month and fascicle dispersal ocurred during 60 days. The dispersal index was 47% and life cycle length 150 (August sowing and 120 (September and October sowings days.

Short Communication: An apospory-specific genomic region is conserved between Buffelgrass (Cenchrus ciliaris L.) and Pennisetum squamulatum Fresen.

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Roche; Cong; Chen; Hanna; Gustine; Sherwood; Ozias-Akins

1999-07-01

Twelve molecular markers linked to pseudogamous apospory, a form of gametophytic apomixis, were previously isolated from Pennisetum squamulatum Fresen. No recombination between these markers was found in a segregating population of 397 individuals (Ozias-Akins et al. 1998, Proc. Natl Acad. Sci. USA, 95, 5127-5132). The objective of the present study was to test if these markers were also linked to the aposporous mode of reproduction in two small segregating populations of Cenchrus ciliaris (= Pennisetum ciliare (L.)Link), another apomictic grass species. Among 12 markers (sequence characterized amplified regions, SCARs), six were scored as dominant markers between aposporous and sexual C. ciliaris genotypes (presence/absence, respectively). Five were always linked to apospory and one showed a low level of recombination in 84 progenies. Restriction fragment length polymorphisms (RFLPs) were observed between sexual and apomictic phenotypes for three of the six remaining SCARs from P. squamulatum when used as probes. No recombination was observed in the F1 progenies. Preliminary data from megabase DNA analysis and sequencing in both species indicate that an apospory-specific genomic region (ASGR) is highly conserved between the two species. Although C. ciliaris has a smaller genome size to P. squamulatum, a higher copy number for markers linked to apospory found in the former may impair the progress of positional cloning of gene(s) for apomixis in this species.

Recombination within the apospory specific genomic region leads to the uncoupling of apomixis components in Cenchrus ciliaris.

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Conner, Joann A; Gunawan, Gunawati; Ozias-Akins, Peggy

2013-07-01

Apomixis enables the clonal propagation of maternal genotypes through seed. If apomixis could be harnessed via genetic engineering or introgression, it would have a major economic impact for agricultural crops. In the grass species Pennisetum squamulatum and Cenchrus ciliaris (syn. P. ciliare), apomixis is controlled by a single dominant "locus", the apospory-specific genomic region (ASGR). For P. squamulatum, 18 published sequenced characterized amplified region (SCAR) markers have been identified which always co-segregate with apospory. Six of these markers are conserved SCARs in the closely related species, C. ciliaris and co-segregate with the trait. A screen of progeny from a cross of sexual × apomictic C. ciliaris genotypes identified a plant, A8, retaining two of the six ASGR-linked SCAR markers. Additional and newly identified ASGR-linked markers were generated to help identify the extent of recombination within the ASGR. Based on analysis of missing markers, the A8 recombinant plant has lost a significant portion of the ASGR but continues to form aposporous embryo sacs. Seedlings produced from aposporous embryo sacs are 6× in ploidy level and hence the A8 recombinant does not express parthenogenesis. The recombinant A8 plant represents a step forward in reducing the complexity of the ASGR locus to determine the factor(s) required for aposporous embryo sac formation and documents the separation of expression of the two components of apomixis in C. ciliaris.

Segmental allotetraploidy and allelic interactions in buffelgrass (Pennisetum ciliare (L.) Link syn. Cenchrus ciliaris L.) as revealed by genome mapping.

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Jessup, R W; Burson, B L; Burow, O; Wang, Y W; Chang, C; Li, Z; Paterson, A H; Hussey, M A

2003-04-01

Linkage analyses increasingly complement cytological and traditional plant breeding techniques by providing valuable information regarding genome organization and transmission genetics of complex polyploid species. This study reports a genome map of buffelgrass (Pennisetum ciliare (L.) Link syn. Cenchrus ciliaris L.). Maternal and paternal maps were constructed with restriction fragment length polymorphisms (RFLPs) segregating in 87 F1 progeny from an intraspecific cross between two heterozygous genotypes. A survey of 862 heterologous cDNAs and gDNAs from across the Poaceae, as well as 443 buffelgrass cDNAs, yielded 100 and 360 polymorphic probes, respectively. The maternal map included 322 RFLPs, 47 linkage groups, and 3464 cM, whereas the paternal map contained 245 RFLPs, 42 linkage groups, and 2757 cM. Approximately 70 to 80% of the buffelgrass genome was covered, and the average marker spacing was 10.8 and 11.3 cM on the respective maps. Preferential pairing was indicated between many linkage groups, which supports cytological reports that buffelgrass is a segmental allotetraploid. More preferential pairing (disomy) was found in the maternal than paternal parent across linkage groups (55 vs. 38%) and loci (48 vs. 15%). Comparison of interval lengths in 15 allelic bridges indicated significantly less meiotic recombination in paternal gametes. Allelic interactions were detected in four regions of the maternal map and were absent in the paternal map.

Cochliotoxin, a Dihydropyranopyran-4,5-dione, and Its Analogues Produced by Cochliobolus australiensis Display Phytotoxic Activity against Buffelgrass (Cenchrus ciliaris).

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Masi, Marco; Meyer, Susan; Clement, Suzette; Cimmino, Alessio; Cristofaro, Massimo; Evidente, Antonio

2017-05-26

Buffelgrass (Pennisetum ciliare or Cenchrus ciliaris) is a perennial grass that has become highly invasive in the Sonoran Desert of southern Arizona. In the search for novel control strategies against this weed, strains of the foliar fungal pathogen Cochliobolus australiensis from buffelgrass have been screened for their ability to produce phytotoxic metabolites that could potentially be used as natural herbicides in an integrated pest management strategy. A new phytotoxin, named cochliotoxin, was isolated from liquid culture of this fungus together with radicinin, radicinol, and their 3-epimers. Cochliotoxin was characterized, essentially by spectroscopic methods, as 3-hydroxy-2-methyl-7-(3-methyloxiranyl)-2,3-dihydropyrano[4,3-b]pyran-4,5-dione. Its relative stereochemistry was assigned by 1 H NMR techniques, while the absolute configuration (2S,3S) was determined applying the advanced Mosher's method by esterification of its hydroxy group at C-3. When bioassayed in a buffelgrass coleoptile elongation test and by leaf puncture bioassay against the host weed and two nontarget grasses, cochliotoxin showed strong phytotoxicity. In the same tests, radicinin and 3-epi-radicinin also showed phytotoxic activity, while radicinol and 3-epi-radicinol were largely inactive. All five compounds were more active in leaf puncture bioassays on buffelgrass than on the nontarget grass tanglehead (Heteropogon contortus), while the nontarget grass Arizona cottontop (Digitaria californica) was more sensitive to radicinin and 3-epi-radicinin. Cochliotoxin at low concentration was significantly more active on buffelgrass than on either native grass, but the difference was small.

Evolution of the apomixis transmitting chromosome in Pennisetum

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Yamada-Akiyama Hitomi

2011-10-01

Full Text Available Abstract Background Apomixis is an intriguing trait in plants that results in maternal clones through seed reproduction. Apomixis is an elusive, but potentially revolutionary, trait for plant breeding and hybrid seed production. Recent studies arguing that apomicts are not evolutionary dead ends have generated further interest in the evolution of asexual flowering plants. Results In the present study, we investigate karyotypic variation in a single chromosome responsible for transmitting apomixis, the Apospory-Specific Genomic Region carrier chromosome, in relation to species phylogeny in the genera Pennisetum and Cenchrus. A 1 kb region from the 3' end of the ndhF gene and a 900 bp region from trnL-F were sequenced from 12 apomictic and eight sexual species in the genus Pennisetum and allied genus Cenchrus. An 800 bp region from the Apospory-Specific Genomic Region also was sequenced from the 12 apomicts. Molecular cytological analysis was conducted in sixteen Pennisetum and two Cenchrus species. Our results indicate that the Apospory-Specific Genomic Region is shared by all apomictic species while it is absent from all sexual species or cytotypes. Contrary to our previous observations in Pennisetum squamulatum and Cenchrus ciliaris, retrotransposon sequences of the Opie-2-like family were not closely associated with the Apospory-Specific Genomic Region in all apomictic species, suggesting that they may have been accumulated after the Apospory-Specific Genomic Region originated. Conclusions Given that phylogenetic analysis merged Cenchrus and newly investigated Pennisetum species into a single clade containing a terminal cluster of Cenchrus apomicts, the presumed monophyletic origin of Cenchrus is supported. The Apospory-Specific Genomic Region likely preceded speciation in Cenchrus and its lateral transfer through hybridization and subsequent chromosome repatterning may have contributed to further speciation in the two genera.

Pyriculins A and B, two monosubstituted hex-4-ene-2,3-diols and other phytotoxic metabolites produced by Pyricularia grisea isolated from buffelgrass (Cenchrus ciliaris).

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Masi, Marco; Meyer, Susan; Górecki, Marcin; Mandoli, Alessandro; Di Bari, Lorenzo; Pescitelli, Gennaro; Cimmino, Alessio; Cristofaro, Massimo; Clement, Suzette; Evidente, Antonio

2017-11-01

Pyricularia grisea has been identified as a foliar pathogen on buffelgrass (Cenchrus ciliaris) in North America and was studied as a potential source of phytotoxins for buffelgrass control. Two monosubstituted hex-4-ene-2,3-diols, named pyriculins A and B, were isolated from its culture filtrate organic extract together with (10S,11S)-(-)-epipyriculol, trans-3,4-dihydro-3,4,8-trihydroxy-1(2H)-napthalenone, and (4S)-(+)-isosclerone. Pyriculins A and B were characterized by spectroscopic (essentially nuclear magnetic resonance [NMR], High-resolution electrospray ionization mass spectrometry [HRESIMS]) and chemical methods such as (4E)-1-(4-hydroxy-1,3-dihydroisobenzofuran-1-yl)hex-4-ene-2,3-diols. The relative and absolute configuration of these compounds was determined by a combination of spectroscopic (NMR, electronic circular dichroism [ECD]) and computational tools. When bioassayed in a buffelgrass coleoptile and radicle elongation test, (10S,11S)-(-)-epipyriculol proved to be the most toxic compound. Seed germination was much reduced and slowed with respect to the control and radicles failed to elongate. All five compounds delayed germination, but only (10S,11S)-(-)-epipyriculol was able to prevent radicle development of buffelgrass seedlings. It had no effect on coleoptile elongation, while the other four compounds caused significantly increased coleoptile development relative to the control. © 2017 Wiley Periodicals, Inc.

Growth, biomass production and photosynthesis of Cenchrus ciliaris L. under Acacia tortilis (Forssk.) Hayne based silvopastoral systems in semi arid tropics.

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Mishra, A K; Tiwari, H S; Bhatt, R K

2010-11-01

The growth, biomass production and photosynthesis of Cenchrus ciliaris was studied under the canopies of 17 yr old Acacia tortilis trees in semi arid tropical environment. On an average the full grown canopy of A. tortilis at the spacing of 4 x 4 m allowed 55% of total Photosynthetically Active Radiation (PAR) which in turn increased Relative Humidity (RH) and reduced under canopy temperature to -1.75 degrees C over the open air temperature. C. ciliaris attained higher height under the shade of A. tortilis. The tiller production and leaf area index decreased marginally under the shade of tree canopies as compared to the open grown grasses. C. ciliaris accumulated higher chlorophyll a and b under the shade of tree canopies indicating its shade adaptation potential. The assimilatory functions such as rate of photosynthesis, transpiration, stomatal conductance, photosynthetic water use efficiency (PN/TR) and carboxylation efficiency (PN/CINT) decreased under the tree canopies due to low availability of PAR. The total biomass production in term of fresh and dry weight decreased under the tree canopies. On average of 2 yr C. ciliaris had produced 12.78 t ha(-1) green and 3.72 -t ha(-1) dry biomass under the tree canopies of A. tortilis. The dry matter yield reduced to 38% under the tree canopies over the open grown grasses. The A. tortilis + C. ciliaris maintained higher soil moisture, organic carbon content and available N P K for sustainable biomass production for the longer period. The higher accumulation of crude protein, starch, sugar and nitrogen in leaves and stem of C. ciliaris indicates that this grass species also maintained its quality under A. tortilis based silvopastoral system. The photosynthesis and dry matter accumulation are closely associated with available PAR indicating that for sustainable production of this grass species in the silvopasture systems for longer period about 55% or more PAR is required.

Review of the genus Neotetricodes Zhang et Chen (Hemiptera: Fulgoromorpha: Issidae) with description of two new species.

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Chang, Zhi-Min; Yang, Lin; Zhang, Zheng-Guang; Chen, Xiang-Sheng

2015-12-11

Two new species of the issid genus Neotetricodes Zhang et Chen (Hemiptera: Fulgoromorpha: Issidae): Neotetricodes longispinus Chang et Chen sp. nov. (China: Yunnan) and Neotetricodes xiphoideus Chang et Chen sp. nov. (China: Yunnan) are described and illustrated. The generic characteristic is redefined. A checklist and key to the species of the genus are provided. The female genitalia of the genus are firstly described.

In Silico and Fluorescence In Situ Hybridization Mapping Reveals Collinearity between the Pennisetum squamulatum Apomixis Carrier-Chromosome and Chromosome 2 of Sorghum and Foxtail Millet

OpenAIRE

Sapkota, Sirjan; Conner, Joann A.; Hanna, Wayne W.; Simon, Bindu; Fengler, Kevin; Deschamps, St?phane; Cigan, Mark; Ozias-Akins, Peggy

2016-01-01

Apomixis, or clonal propagation through seed, is a trait identified within multiple species of the grass family (Poaceae). The genetic locus controlling apomixis in Pennisetum squamulatum (syn Cenchrus squamulatus) and Cenchrus ciliaris (syn Pennisetum ciliare, buffelgrass) is the apospory-specific genomic region (ASGR). Previously, the ASGR was shown to be highly conserved but inverted in marker order between P. squamulatum and C. ciliaris based on fluorescence in situ hybridization (FISH) a...

Morphological evaluation of buffelgrass cultivar “Lucero INTA-PEMAN” in drought conditions

OpenAIRE

GRIFFA, S.; RIBOTTA, A; LUNA, C; BOLLATI, G; LÓPEZ COLOMBA, E.; TOMMASINO, E; CARLONI, E; QUIROGA, M.; GRUNBERG, K

2011-01-01

In searching for new cultivars that are better adapted to edapho-climatic constraints existing in northwestern Argentina, mainly drought and salinity stress, a hybrid of buffelgrass (Cenchrus ciliaris L.) named Lucero INTA PEMAN was obtained by controlled crosses at the Instituto de Fitopatología y Fisiología Vegetal, INTA. The objective was to morphologically evaluate and compare Cenchrus ciliaris cv Lucero with Texas-4464, Biloela and Molopo cultivars in Dean Funes (North of the Province of...

In Silico and Fluorescence In Situ Hybridization Mapping Reveals Collinearity between the Pennisetum squamulatum Apomixis Carrier-Chromosome and Chromosome 2 of Sorghum and Foxtail Millet.

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Sirjan Sapkota

Full Text Available Apomixis, or clonal propagation through seed, is a trait identified within multiple species of the grass family (Poaceae. The genetic locus controlling apomixis in Pennisetum squamulatum (syn Cenchrus squamulatus and Cenchrus ciliaris (syn Pennisetum ciliare, buffelgrass is the apospory-specific genomic region (ASGR. Previously, the ASGR was shown to be highly conserved but inverted in marker order between P. squamulatum and C. ciliaris based on fluorescence in situ hybridization (FISH and varied in both karyotype and position of the ASGR on the ASGR-carrier chromosome among other apomictic Cenchrus/Pennisetum species. Using in silico transcript mapping and verification of physical positions of some of the transcripts via FISH, we discovered that the ASGR-carrier chromosome from P. squamulatum is collinear with chromosome 2 of foxtail millet and sorghum outside of the ASGR. The in silico ordering of the ASGR-carrier chromosome markers, previously unmapped in P. squamulatum, allowed for the identification of a backcross line with structural changes to the P. squamulatum ASGR-carrier chromosome derived from gamma irradiated pollen.

In Silico and Fluorescence In Situ Hybridization Mapping Reveals Collinearity between the Pennisetum squamulatum Apomixis Carrier-Chromosome and Chromosome 2 of Sorghum and Foxtail Millet.

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Sapkota, Sirjan; Conner, Joann A; Hanna, Wayne W; Simon, Bindu; Fengler, Kevin; Deschamps, Stéphane; Cigan, Mark; Ozias-Akins, Peggy

2016-01-01

Apomixis, or clonal propagation through seed, is a trait identified within multiple species of the grass family (Poaceae). The genetic locus controlling apomixis in Pennisetum squamulatum (syn Cenchrus squamulatus) and Cenchrus ciliaris (syn Pennisetum ciliare, buffelgrass) is the apospory-specific genomic region (ASGR). Previously, the ASGR was shown to be highly conserved but inverted in marker order between P. squamulatum and C. ciliaris based on fluorescence in situ hybridization (FISH) and varied in both karyotype and position of the ASGR on the ASGR-carrier chromosome among other apomictic Cenchrus/Pennisetum species. Using in silico transcript mapping and verification of physical positions of some of the transcripts via FISH, we discovered that the ASGR-carrier chromosome from P. squamulatum is collinear with chromosome 2 of foxtail millet and sorghum outside of the ASGR. The in silico ordering of the ASGR-carrier chromosome markers, previously unmapped in P. squamulatum, allowed for the identification of a backcross line with structural changes to the P. squamulatum ASGR-carrier chromosome derived from gamma irradiated pollen.

Effect of substitution of groundnut with high glucosinolate mustard (Brassica juncea) meal on nutrient utilization, growth, vital organ weight and blood composition of lambs.

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Tripathi, M K.; Mishra, A S.; Misra, A K.; Mondal, D; Karim, S A.

2001-03-01

Twenty-four 14-day-old weaner Avivastra (Russian MerinoxNali) male lambs were maintained for 180 days on ad libidum Cenchrus (Cenchrus ciliaris) hay and concentrate mixture (CM) contained groundnut meal (control) and mustard meal (MM group) as major protein source. The two CMs were isonitrogenous (21% CP) and isocaloric (2.78McalMEkg(-1) DM), while, CM fed to MM group contained 24.6mg glucosinolatesg(-1) DM. Digestibility of nutrients was similar (P>0.05) in the two groups except for CP and hemicellulose, which was higher (P0.05) in the two groups. Average daily gain (ADG) was, however, 22% higher (Pgrowth rate and induced iodine deficiency. Carcass of lambs fed mustard meal had more fat and less protein.

Efeitos de misturas de dinitramine e diuron em pré-plantio incorporado na cultura do algodão (Gossypium hirsutum L. Effects of dinitramine and diuron mixtures applied pre-planting incorporated on cotton (Gossypium hirsutum L.

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R. Victoria Filho

1982-06-01

dinitramine and diuron mixtures on weed control in cotton at two experiments at Casa Branca - SP on a clay soil (3 ,6% organic matter and Jaboticabal - SP on a clay loam (2,3% organic matter. The cotton variety sowed was IAC-13 -1 at Casa Branca (nov, 05, 1975 and RM-4A at Jaboticabal (dec. 3, 1975. The experiment had a design of randomized blocks with the treatments dinitramine at 0.25 kg; 0.40 kg; 0.50 kg/ha; diuron at 1.20 kg; 1.50 kg; 1.80 kg/ha and ali dinitramine + diuron mixture s with this rates; one treatment with trifluralin + diuron at 1.00 + 1.20 kg/ha, and one hoeded treatment. The best weed control results on the clay soil were obta ined by the mixtures when compared with the dinitramine and diuron appl ication on large crabgrass (Digitaria sanguinallis (L. Scop., go ose gras s (Eleusine indica (L . Gaertn., Paraguay starbur (Acanthospermum australe ( Loef. O. Kuntze, Borreria alata (Aubl. D.C., Brasil callalily (Richardia brasiliensis Gomez and sidas (Sida spp. but on the clay loam soil were the most important weeds we re la r ge c rabg ras s , s outhe rn s andbur (Cenchrus echinatus L. , West Indies pennisetum (Pennisetum setosum (L. Rich. Pers, Paraguay sandbur, Brasil callalily and sidas the be st weed control results were obtained with trifluralin + diuron and with dinitramine at 0.25 kg; 0.40 kg; 0.50 kg in mixture with diuron at 1.80 kg/ha. The treatments used didn't present any phyto toxicity to cotton at the initial development and there wasn't significant difference in the total yield.

jfewr ©2016 - jfewr Publications

African Journals Online (AJOL)

B.L. PENUEL

Terminalia albida, Ziziphus spina-christi, Sena siamea, Annona senegalensis, Terminalia glaucescens, Guiera senegalensis, Tamarindus indica and Grewia venusta while the abundant grass species are: Cenchrus species, Sena obtusifolia, Sida acuta, Hibiscus asper, Tridax procumbens, Croton lobatus and Portulaca.

A new species complex including Claviceps fusiformis and Claviceps hirtella

Czech Academy of Sciences Publication Activity Database

Pažoutová, Sylvie; Kolařík, Miroslav; Odvody, G.; Frederickson, D. E.; Olšovská, Jana; Man, Petr

2008-01-01

Roč. 31, - (2008), s. 95-110 ISSN 1560-2745 Grant - others:US(US) Intsormil Institutional research plan: CEZ:AV0Z50200510 Keywords : alkaloids * cenchrus * claviceps Subject RIV: EE - Microbiology, Virology Impact factor: 2.279, year: 2008

Caracterización de producción de etanol a partir de zacate buffel y sus implicaciones ambientales

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Kareen Krizzan Encinas Soto

2016-12-01

Full Text Available En esta investigación se caracterizó el potencial para la obtención de etanol a partir de la planta silvestre Cenchrus ciliaris, también conocida como zacate buffel. A partir de estudios experimentales a nivel laboratorio, se determinaron los rendimientos técnicos y requerimientos energéticos de las etapas de pretratamiento ácido, hidrólisis enzimática y fermentación. Los valores obtenidos fueron comparados con los reportados en la literatura para otros procesos de producción de combustibles. Los resultados del presente trabajo indican que el procesamiento de Cenchrus ciliaris consume la tercera parte de la energía requerida para procesar gasolina por 1 MJ de etanol producido. Asimismo, mediante este proceso es factible la reducción de las emisiones de gases de efecto invernadero por 1 MJ de energía de etanol producido en aproximadamente 40 % su valor actual.

Analyse de la dynamique des pâturages autour des ouvrages ...

African Journals Online (AJOL)

The dynamics are characterized by the proliferation of Acaciatortilis and Balanites aegyptiaca due to the movement of animals and ancestry of Cenchrus biflorus and Schoenefeldia gracilis on other herbaceous species. However, livestock wells do not pose a threat to the future production of these spaces because they ...

Ploidy determination of buffel grass accessions in the USDA National Plant Germplasm System collection by flow cytometry

Science.gov (United States)

Buffelgrass [Pennisetum ciliare (L.) Link syn. Cenchrus ciliaris L.] is an important forage and range grass in many of the semi-arid tropical and subtropical regions of the world. The species reproduces primarily by apomixis but it is highly diverse because a wide array of different apomictic ecoty...

Soil erosion studies in buffelgrass pastures

Science.gov (United States)

Diego Valdez-Zamudio; D. Phillip Guertin

2000-01-01

The introduction of exotic grasses in native rangelands to increase the production of forage has been a good alternative for the cattle industry in North America. Different studies have demonstrated that buffelgrass (Cenchrus ciliaris L.), a plant introduced from Africa, increases the annual green forage production approximately three times in comparison to production...

Essential oil of some seasonal flowering plants grown in Saudi Arabia

OpenAIRE

S.A. Al-Mazroa; L.H. Al-Wahaibi; A.A. Mousa; H.Z. Al-Khathlan

2015-01-01

The constituents of the essential oils of Rumex vesicarius, Erucaria hispanica, Schimpera arabica, Savignya parviflora, Horwoodia dicksoniae, Sisymbrium irio, Plantago amplexicaulis, Plantago boissieri, Arnebia linearifolia, Foeniculum vulgare, Trigonella hamosa, Lotus halophilus, Reseda muricata, Cenchrus ciliaris is reported. These oils were analyzed by GC/MS and most of them are being studied for the first time.

the utilisation of ctnchrus and paivicum pastures or lucerne hay for ...

African Journals Online (AJOL)

At lhis rate the Panit'um pasture farled to provide an adequate mainlenance diet for the entire period of the trraf, but the Cenchrus pasture produccd ... season sheep were grazed in rotation around paddocks, being moved at 3 to 4-day intervals ... was possible to skip certain paddocks in the rotation and surplus growth was ...

Notulae to the Italian alien vascular flora: 4

OpenAIRE

Galasso,Gabriele; Domina,Gianniantonio; Bonari,Gianmaria; Buono,Sergio; Chianese,Giuseppina; Cortesi,Gloria; Cortesi,Gloria; Iamonico,Duilio; Olivieri,Nicola; Peruzzi,Lorenzo; Pierini,Brunello; Roma-Marzio,Francesco; Scoppola,Anna; Soldano,Adriano; Stinca,Adriano

2017-01-01

In this contribution, new data concerning the Italian distribution of alien vascular flora are presented. It includes new records and exclusions for Italy or for Italian administrative regions of taxa in the genera Cedrus, Cenchrus, Citrus, Cyrtomium, Diospyros, Elaeagnus, Erigeron, Iris, Oenothera, Pavonia, Phytolacca, Styphnolobium, and Verbena. Furthermore, a new combination in the genus Amaranthus is proposed.

Essential oil of some seasonal flowering plants grown in Saudi Arabia

Directory of Open Access Journals (Sweden)

S.A. Al-Mazroa

2015-03-01

Full Text Available The constituents of the essential oils of Rumex vesicarius, Erucaria hispanica, Schimpera arabica, Savignya parviflora, Horwoodia dicksoniae, Sisymbrium irio, Plantago amplexicaulis, Plantago boissieri, Arnebia linearifolia, Foeniculum vulgare, Trigonella hamosa, Lotus halophilus, Reseda muricata, Cenchrus ciliaris is reported. These oils were analyzed by GC/MS and most of them are being studied for the first time.

Final Environmental Assessment Implementation of the Integrated Natural Resources Management Plan for Avon Park Air Force Range Florida

Science.gov (United States)

2004-01-01

divine nightshade (Solanum nigrescens) Coast sandspur (Cenchrus incertus) Three plants — tropical soda apple (Solanum viarum), cogon grass ( Imperata ...consequence on the APAFR ecosystem. However in the last 5 years, there has been an increase in the number of sites where cogon grass ( Imperata ...verticillata Hydrilla Hymenachne amplexicaulis West In mdian arsh grass Imperata cylindrica Cogon grass Lantana camara Lantana Ligustrum sinense Chinese

Morphological evaluation of buffelgrass cultivar “Lucero INTA-PEMAN” in drought conditions

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GRIFFA, S.

2011-04-01

Full Text Available In searching for new cultivars that are better adapted to edapho-climatic constraints existing in northwestern Argentina, mainly drought and salinity stress, a hybrid of buffelgrass (Cenchrus ciliaris L. named Lucero INTA PEMAN was obtained by controlled crosses at the Instituto de Fitopatología y Fisiología Vegetal, INTA. The objective was to morphologically evaluate and compare Cenchrus ciliaris cv Lucero with Texas-4464, Biloela and Molopo cultivars in Dean Funes (North of the Province of Córdoba, Argentina under drought field conditions using a randomized complete block design with three replications in two crop cycles (2006/2007 and 2007/2008 considering one-year plant and re-growth as ontogenic stages of the plant, respectively. Thirteen morphological characters were analyzed by ANOVA and DGC testing (p <0.05. Although most of the thirteen morphological characters evaluated showed decreased re-growth over one-year plants, Lucero was least affected by low water availability, showed highest values for seed production components in both ontogenic stages and was superior to Texas-4464 in biomass production characters and to Biloela and Molopo cultivars in most of them. Lucero showed a promising and considerable forage value for drought-affected regions, such as northwestern Argentina.

Seedbed preparation influence on morphometric characteristics of perennial grasses of a semi-arid rangeland in Kenya

OpenAIRE

Opiyo, Francis EO; Ekaya, Wellington N; Nyariki, Dickson M; Mureithi, Stephen Mwangi

2011-01-01

Semi-arid rangelands in Kenya are an important source of forage for both domestic and wild animals. However, indigenous perennial grasses notably Cenchrus ciliaris (African foxtail grass), Eragrostis superba (Maasai love grass) and Enteropogon macrostachyus (Bush rye grass) are disappearing at an alarming rate. Efforts to re-introduce them through restoration programs have often yielded little success. This can partly be attributed to failure of topsoil to capture and store scarce water to me...

Levantamento de plantas infestantes em lavouras de milho 'safrinha'no estado de São Paulo Weed survey in autumn corn crops in the state of São Paulo, Brazil

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Aildson P. Duarte

1999-08-01

Full Text Available Fez-se o levantamento da flora infestante na lavoura do milho "safrinha" nas duas principais regiões de plantio no Estado de São Paulo, em 1995. Foram visitadas 85 lavouras na Região do Médio Vale do Paranapanema e 29 na Região Norte. Nesta, em quatro lavouras fez-se a semeadura na palha e em 25, em solo com preparo de gradagem simples, todos sem herbicida. Naquela, a semeadura na palha foi em 68 lavouras, em 11 fez-se gradagem simples e, em seis, gradagem dupla, havendo aplicação de herbicidas de POS em algumas áreas. As espécies que ocorreram, segundo a sua freqüência, foram, na Região Norte: Glycine max> Amaranthus retroflexus> Acanthospermum hispidum = Bidens pilosa = Alternanthera tenella > Cenchrus echinatus > Euphorbia heterophylla > Ipomoea spp. > Commelina benghalensis > Sida spp. = Eleusine indica; e, na Região do Médio Vale do Paranapanema: Euphorbia heterophylla = Glycine max = Commelina benghalensis > Bidens pilosa = Raphanus sativus > Cenchrus echinatus = Acanthospermum hispidum > Brachiaria plantaginea > Sida spp. = Coronopus didymus > Eleusine indica > Digitaria horizontalis > Amaranthus retroflexus. O preparo do solo com gradagem dupla, resultou em menor índice de ocorrência de alta infestação, seguida da gradagem simples. O uso de herbicidas, de modo geral, também reduziu esse índice. As espécies Commelina benghalensis, Digitaria horizontalis, Sida spp., Eleusine indica e Amaranthus hibridus ocorreram apenas com a semeadura direta na Região do Paranapanema. Na Região Norte, Ipomoea spp. e Euphorbia heterophylla só ocorreram nas áreas com gradagem simples.A weed infestation survey was carried out in the two main cultivation regions of autumn corn crops in the State of São Paulo. In the Médio Vale do Paranapanema 85 plantations were visited and in the Região Norte 29 plantations. In this region four crops were sowed directly and 25 after soil preparation with a single harrowing, all without herbicides

Modelagem geoestatística da distribuição de carbono do solo e biomassa de herbáceas em sistema silvopastoril.

OpenAIRE

Marystella Duarte Correia

2013-01-01

Estudos de algumas regiões semiáridas têm apontado o efeito benéfico de certas espécies de árvores em sistemas silvopastoris, por promoverem a formação de fertilidade do solo e aumentarem a sustentabilidade da produtividade agrícola. Neste trabalho, foram selecionadas três espécies arbóreas encontradas em pastagens de Capim buffel (Cenchrus ciliaris), juazeiro (Zyziphus joazeiro), umbuzeiro (Spondias tuberosa) e algaroba (Prosopis juliflora) da caatinga, bioma exclusivamente brasileiro,...

Moringa oleifera leaf extract: An innovative priming tool for rangeland grasses

OpenAIRE

NOUMAN, Wasif; SIDDIQUI, Muhammad Tahir; BASRA, Shahzad Maqsood Ahmed

2012-01-01

Moringa oleifera leaf extract (MLE) is rich in amino acids, ascorbate, zeatin, minerals, and many other compounds known for their growth-promoting potential. This study was planned to explore the potential of MLE as a seed priming agent to increase the germination rate and plant vigor of 3 range grasses, i.e. Cenchrus ciliaris, Panicum antidotale, and Echinochloa crusgalli. The priming strategies used were hydropriming, CaCl2, PEG-8000 (-1.1 M Pa), MLE (concentrate; 1:10, 1:20, 1:30, and 1:40...

Evaluación morfológica del cultivar de buffelgrass “Lucero INTA-PEMAN” en condiciones de sequía

OpenAIRE

GRUNBERG, K; QUIROGA, M; CARLONI, E; TOMMASINO, E; BOLLATI, G; LÓPEZ COLOMBA, E; LUNA, C; RIBOTTA, A; GRIFFA, S

2011-01-01

En la búsqueda de nuevos cultivares nacionales mejor adaptados a las restricciones edafo-climáticas presentes en el noroeste argentino, principalmente estrés por sequía y salinidad, un híbrido de buffelgrass (Cenchrus ciliaris L.) denominado Lucero INTA-PEMAN fue obtenido mediante cruzamientos controlados en el Instituto de Fitopatología y Fisiología Vegetal (IFFIVE), INTA. El objetivo fue evaluar morfológicamente al cultivar Lucero en comparación a los cultivares Texas-4464, Biloela y Molopo...

Utilización de la leucaena leucocephala como suplemento en cabras en crecimiento

OpenAIRE

Clavero, Tyrone; Razz, Rosa

2009-01-01

Con el objeto de evaluar el crecimiento de cabras mestizas (Nubian x Criollo) suplementadas con Leucaena leucocephala, se realizó un ensayo en el Occidente de Venezuela en una zona caracterizada como Bosque muy Seco Tropical. Se evaluaron tres raciones: T1 (pastoreo en gramínea-Cenchrus cillaris), T2 (pastoreo en gramínea + 2 h/día en Leucaena), T3 (pastoreo en gramínea + alimento concentrado comercial, 300 g/animal/día). El diseño experimental fue de bloques completamente al azar. El peso de...

Avaliação de fenos de capim-buffel colhido em diferentes alturas de corte

OpenAIRE

Pinho, Ricardo Martins Araujo; Santos, Edson Mauro; Bezerra, Higor Fábio Carvalho; Oliveira, Juliana Silva de; Carvalho, Gleidson Giordano Pinto de; Campos, Fleming Sena; Pereira, Gildenia Araujo; Correia, Robervânia Maria

2013-01-01

Objetivou-se avaliar o rendimento forrageiro, composição bromatológica e recuperação de matéria seca do feno de capim-buffel (Cenchrus ciliaris L.), colhido em diferentes alturas de corte. O experimento foi realizado na Estação Experimental Pendência, da Empresa Estadual de Pesquisa Agropecuária da Paraíba S.A. (EMEPA), situada no Município de Soledade-PB. Utilizou-se um delineamento experimental em blocos casualizados, com quatro alturas de corte (30; 40; 50 e 60cm) e cinco repetições. O ren...

Chemical constituents of Cenchrus ciliaris L. from the Cholistan desert, Pakistan

OpenAIRE

Ashraf Muhammad Aqeel; Mahmood Karamat; Yusoff Ismail; Qureshi Ahmad Kaleem

2013-01-01

The Cholistan Desert is an extension of the Great Indian Desert, covering an area of 26,330 km2. The desert can be divided into two main geomorphic regions: the northern region, known as Lesser Cholistan, constituting the desert margin and consisting of a series of saline alluvial flats alternating with low sand ridges/dunes; and the southern region, known as Greater Cholistan, a wind-resorted sandy desert comprised of a number of old Hakra River terraces w...

Comportamento de espécies herbáceas em misturas de solo com diferentes graus de contaminação com metais pesados

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Carneiro Marco Aurélio Carbone

2002-01-01

Full Text Available O objetivo deste trabalho foi avaliar, em casa de vegetação, o comportamento de espécies herbáceas em relação ao excesso de Cd e Zn no solo. O gradiente de contaminação foi estabelecido a partir de mistura de solo contaminado com solo sem contaminação em diferentes proporções. As sementes foram semeadas em tubetes contendo 250 mL de solo, e após 90 dias as plantas foram colhidas e avaliadas. A maioria das espécies apresentou redução no crescimento com aumento da contaminação do solo e elevadas concentrações de Cd e Zn na matéria seca da parte aérea (MSPA, na mistura com 15% de solo contaminado. A espécie Pffafia sp. mostrou-se tolerante à contaminação, crescendo em misturas de solo contendo até 90 mg kg-1 de Cd e 1.450 mg kg-1 de zinco. Além disso, apresentou concentração superior a 100 mg kg-1 de Cd na MSPA, sendo considerada hiperacumuladora desse metal. Sida glaziovii, Bidens pilosa, Rhynchelytrum repens, Cenchrus echinatus e Nicandra physaloides, por sua vez, foram severamente afetadas pela contaminação, ao contrário de Trifolium repens, Euchlaena mexicana, Cynodon dactylon, Avena strigosa, Cenchrus ciliares e Cyperus sp. que apresentaram crescimento satisfatório. As espécies avaliadas mostram-se promissoras para estudos adicionais sobre a reabilitação de áreas contaminadas com metais pesados.

New xenophytes from Gran Canaria (Canary Islands, Spain, with emphasis on naturalized and (potentially invasive species

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Verloove, F.

2013-12-01

Full Text Available Trabajos recientes de campo en Gran Canaria han facilitado el descubrimiento de nuevas localidades para plantas vasculares no nativas. Agave attenuata, Antigonon leptopus, Atriplex nummularia, Cascabela thevetia, Cenchrus echinatus, Cuscuta campestris, Diplachne fusca subsp. uninervia, Diplotaxis tenuifolia, Dysphania anthelmintica (hasta ahora confundida con D. ambrosioides, Eclipta prostrata, Euphorbia pulcherrima, Fagopyrum esculentum, Gossypium barbadense, Lablab purpureus, Lemna minuta, Opuntia leucotricha, Passiflora edulis, Pennisetum glaucum, Phaseolus acutifolius, Pluchea carolinensis, Prosopis juliflora, Salvia microphylla, Schinus terebinthifolius, Senna spectabilis, Solanum chrysotrichum, Tecoma stans, Tipuana tipu, Urochloa mutica, U. plantaginea y Washingtonia se citan por primera vez para las Islas Canarias, mientras que Alopecurus myosuroides, Amaranthus blitoides, Bothriochloa ischaemum var. songarica, Cardamine flexuosa subsp. debilis, Heliotropium curassavicum, Leonotis nepetifolia, Medicago lupulina, Parkinsonia aculeata, Physalis peruviana, Phytolacca americana y Turnera ulmifolia son nuevas para la flora de la isla de Gran Canaria. Finalmente, se confirma la presencia de Paspalum vaginatum, P. distichum y Cortaderia selloana en Gran Canaria.Trabajos recientes de campo en Gran Canaria han facilitado el descubrimiento de nuevas localidades para plantas vasculares no nativas. Agave attenuata, Antigonon leptopus, Atriplex nummularia, Cascabela thevetia, Cenchrus echinatus, Cuscuta campestris, Diplachne fusca subsp. uninervia, Diplotaxis tenuifolia, Dysphania anthelmintica (hasta ahora confundida con D. ambrosioides, Eclipta prostrata, Euphorbia pulcherrima, Fagopyrum esculentum, Gossypium barbadense, Lablab purpureus, Lemna minuta, Opuntia leucotricha, Passiflora edulis, Pennisetum glaucum, Phaseolus acutifolius, Pluchea carolinensis, Prosopis juliflora, Salvia microphylla, Schinus terebinthifolius, Senna spectabilis, Solanum

Dynamique de la flore et de la végétation des Niayes et du Bassin arachidier au Sénégal

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Elhadji Faye

2014-12-01

Full Text Available Reactualisation of floristic and phytosociologic datas in Niayes and Peanut-Basin areas were undertook with village scale approach to better underline resources' conervation. In Savannah and sub-guinean areas specially in the Peanut-Basin and Niayes, 288 floristic samples were put in place in 6 villages in an stratified way based on ethnic groups, land use systems and topography. In the same time, 25 samples were realised in the 2 reference sites (Noflaye and Sambandé and comparison were made with researches conducted in 1940. Datas were submitted to multivariate analysis. SØrensen similarity index were used to compare villages systems and natural sites. Results showed discrimination of 11 phytosociologic groups: 5 of which came from natural sites (savanah G4 Hexalobus monopetalus et Gardenia ternifolia and G8 Acacia macrostachya et Ischaemum rugosum, secondary forest G10 Aphania senegalensis et Voaganca africana, semi-aquatic vegetations G1 Ipomoea aquatica et I. dichroa and G5 Phragmites australis subsp australis et Paspalum vaginatum and 6 from anthropic systems (disturbed areas G6 Echinochloa colona et Jussiae erecta and G7 Dactyloctenium aegyptium et Brachiaria disticophylla, and finally post-cultural zones with G2 Brachiaria disticophylla et Cenchrus biflorus, G3 Celosia trigyna et Digitaria velutina, G9 Tephrosia purpurea et Cenchrus biflorus and G11 Mitracarpus scaber et Eragrostis tremula. Natural sites groups were progressively invided by disturded area species and the others by ruderals and nitrophyl species. Overall floristic richness is about 336 species among which 260 from the Niayes sites and 176 from Peanut-Basin ones. References sites are always richer in terms af genera but peul areas are richer in termes of species. Differences were evidenced between actual taxa and Trochain (1940 descriptions. This methodological approach might be extended to other ecogeographical zones in Senegal in order to better identify and follow

Competição entre feijoeiros e plantas daninhas em função do tipo de crescimento dos cultivares Competition between the common bean and weed in function of cultivar growth type

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I.R. Teixeira

2009-06-01

Full Text Available Objetivou-se com este trabalho avaliar a capacidade competitiva de genótipos de feijão de diferentes tipos de crescimento sob presença e ausência de comunidade infestante de plantas daninhas, em duas safras de cultivo ("águas'' de 2006/07 e "seca'' de 2007. Foi utilizado o delineamento de blocos casualizados, em esquema fatorial 3 x 2, com quatro repetições. Os tratamentos foram constituídos de três cultivares de feijão com diferentes tipos de crescimento (Pérola: tipo III/II; Aporé: tipo III; e BRS Radiante: tipo I, em combinação com dois tipos de manejo de plantas daninhas: área capinada manualmente e área não capinada. Conclui-se que no cerrado brasileiro, na safra das "águas'', os problemas da cultura do feijão com as plantas daninhas foram agravados, especialmente com Brachiaria ssp., Cenchrus echinatus, Digitaria horizontalis e Eleusine indica. Os cultivares de feijão com hábitos de crescimento semiereto (Pérola e prostrado (Aporé foram mais competitivos com a comunidade infestante de plantas daninhas.This work aimed to evaluate the competitive capacity of common bean cultivars of different growth types under the presence and absence of weed species communities during two crop seasons(rainy 2006/2007 and dry 2007. The experiment was arranged in a randomized block design, in a factorial scheme with four replications. The treatments consisted of three bean cultivars with different types of growth ("Pérola'': type III/II, "Aporé'': type III and "BRS Radiante'': type I in combination with two types of management of weed species: cultivated with and without weed. It was concluded that in the "cerrado'' during the rainy season, the problems of the common bean with the weed species aggravated, especially in relation to Brachiaria ssp., Cenchrus echinatus, Digitaria horizontalis and Eleusine indica. The common bean genotypes with semi-erect ("Pérola'' and prostrated ("Aporé' growth habits were more competitive against

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

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Maria Rosangela Malheiros Silva

2009-01-01

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

AUTOPOLINIZACIÓN EN LA PRODUCCIÓN DE SEMILLA DE PASTO BUFFEL (Cenchrus ciliaris L.

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Elizabeth Conde-Lozano

2011-01-01

Full Text Available El objetivo de este estudio fue determinar el efecto de la polinización libre y la autopolinización en el pasto Buffel. El estudio se realizó en el invernadero y en el campo de la Unidad Académica Multidisciplinaria Agronomía y Ciencias (UAMAC en el Municipio de Victoria, Tamaulipas. Se utilizaron cuatro variedades de pasto Buffel (Común, Nueces, T-1754 y Formidable las cuales fueron sometidas a dos tipos de polinización (libre y auto. Se utilizó un diseño en bloques completos al azar. Se midieron los días a floración de los órganos masculinos y femeninos. Se clasificó el polen (fértil, intermedio e infértil y los efectos de la autopolinización y polinización libre sobre las características de las semillas. No se observaron efectos sobre los días a floración de los órganos femeninos (P = 0,54, pero sí en los órganos masculinos (P < 0,03, donde las plantas de la variedad Formidable tardaron 2,3 días en madurar. El número de granos de polen fértil, intermedio e infértil no fueron afectados por la polinización ni por la variedad. En cuanto a los componentes de la semilla, todos fueron afectados (P < 0,01 por el tipo de polinización, las plantas sometidas a autopolinización mostraron las mejores características. La polinización afectó las características de la semilla.

Influence of diets with silage from forage plants adapted to the semi-arid conditions on lamb quality and sensory attributes.

Science.gov (United States)

Campos, F S; Carvalho, G G P; Santos, E M; Araújo, G G L; Gois, G C; Rebouças, R A; Leão, A G; Santos, S A; Oliveira, J S; Leite, L C; Araújo, M L G M L; Cirne, L G A; Silva, R R; Carvalho, B M A

2017-02-01

Quality and sensory attributes of meat from 32 mixed-breed Santa Inês lambs fed diets composed of four silages with old man saltbush (Atriplex nummularia Lind), buffelgrass (Cenchrus ciliaris), Gliricidia (Gliricidia sepium), and Pornunça (Manihot sp.) were evaluated. Meat from lambs fed diet containing old man saltbush silage (Pcooking loss. Of the sensory attributes evaluated in the Longissimus lumborum muscle of the lambs, color and juiciness did not differ (P>0.05). However, the silages led to differences (Plambs that consumed old man saltbush silage and lower in the meat from those fed buffelgrass silage. Diets formulated with buffelgrass silage for sheep reduce meat production. Based on the results for carcass weight and meat quality, old man saltbush and pornunça are better silages for finishing sheep. Copyright © 2016 Elsevier Ltd. All rights reserved.

Cadastramento fitossociológico de plantas daninhas na cultura de girassol Phytosociological census of weeds in the sunflower crop

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Alexandre Magno Brighenti

2003-05-01

Full Text Available O objetivo deste trabalho foi realizar um levantamento das plantas daninhas infestantes na précolheita da cultura de girassol em lavouras dos municípios do sudoeste goiano (Chapadão do Céu, Jataí e Montividiu e em Chapadão do Sul, MS. Foram amostradas, no período de maio a junho de 2002, 51 propriedades dos quatro municípios, totalizando uma área de 583 m². As espécies daninhas foram identificadas e contadas mediante a aplicação de um quadrado de 1,0x1,0 m, colocado ao acaso dentro da área ocupada pelas lavouras. Foram obtidos os valores de freqüência, densidade, abundância e índice de importância relativa. Plantas voluntárias de soja e de milho fazem parte da flora daninha infestante de lavouras de girassol dessa região. As famílias Poaceae, Asteraceae e Euphorbiaceae são as que apresentam maior número de espécies. As principais plantas daninhas infestantes na região são, em ordem decrescente, Ageratum conyzoides, Chamaesyce hirta, Cenchrus echinatus, Bidens sp., Euphorbia heterophylla e Commelina benghalensis.The objective of this work was to survey the weeds in the preharvest of the sunflower crop in growers field of the southwest regions of Goiás State (Chapadão do Céu, Jataí and Montividiu and Chapadão do Sul, Mato Grosso do Sul State, Brazil. Fifty one farms were evaluated, during the period of May to June, 2002, in a total of 583 m² of area. The weeds were identified and counted inside a square (1.0x1.0 m, applied in each area, in order to determine the frequency, density, abundance and relative importance. Volunteer soybean (Glycine max and corn (Zea mays are part of the weed species in sunflower crop in the area. The botanical families Poaceae, Asteraceae and Euphorbiaceae present larger number of species. The main weeds found in the area are, in decreasing order, Ageratum conyzoides, Chamaesyce hirta, Cenchrus echinatus, Bidens sp., Euphorbia heterophylla and Commelina benghalensis.

Pendimethalin aplicado à casca de arroz e serragem para o controle de plantas daninhas em Ixora chinensis Lam. Pendimethalin applied on rice husks and sawdust for weed control on Ixora chinensis Lam

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André Luis Seixas

2011-08-01

Full Text Available A aplicação de herbicidas residuais à coberturas mortas pode aumentar a eficiência desses materiais no manejo da comunidade infestante. Objetivou-se, com este trabalho, avaliar a possibilidade de aplicação do pendimethalin à casca de arroz e à serragem para o controle de plantas daninhas em Ixora chinensis. Dois experimentos foram conduzidos aplicando-se o pendimethalin às coberturas mortas através de embebição e pulverização do herbicida, variando-se também a quantidade de cobertura utilizada. As espécies de plantas daninhas que ocorreram com maior frequência foram Alternanthera tenella, Blainvillea rhomboidea, Cenchrus echinatus e Commelina benghalensis. Há possibilidade de aplicação do herbicida pendimethalin à palha de arroz ou à serragem para controle de plantas daninhas em I. chinensis, principalmente quando ocorrem chuvas regulares e bem distribuídas. Há evidências de que a embebição da cobertura morta no herbicida seja um pouco mais eficiente no controle das plantas daninhas que a sua pulverização sobre a cobertura. Possivelmente, a quantidade de cobertura morta utilizada influencia na eficiência de controle, apesar deste fato não ter ficado claro neste trabalho.Applying herbicides at mulches may increase the efficiency of these materials for weed management. The objective of this research was to evaluate the possibility of pendimethalin applied on rice husks and sawdust for weed control on Ixora chinensis. In two field trials, pendimethalin was applied to the mulches through imbibition and spraying herbicide, also varying the amount of mulches. Higher frequent weeds were Alternanthera tenella, Blainvillea rhomboidea, Cenchrus echinatus and Commelina benghalensis. There are possibility of pendimethalin application on rice husks or sawdust for controlling weeds in I. chinensis mainly when regular and well-distributed rainfalls occur. There are evidences that the imbibition of these mulches to the herbicide

A preliminaryfloristic checklist of thal desert punjab, pakistan

International Nuclear Information System (INIS)

Shaheen, H.; Qureshi, R.

2014-01-01

The floristic survey of the Thal desert, Punjab, Pakistan was carried out during 2010 to 2013. So far, 248 species distributed across 166 genera and 38 families were identified during the report period. Besides, one species viz., Themeda triandra was recorded for the first time from Pakistan. Of them, one fern, 4 monocots and 33 dicots families were determined. The most dominating family was Poaceae that contributed 52 species (21.49%), followed by Fabaceae (34 spp., 13.05%) and Amaranthaceae and Asteraceae (17 spp., 7.02% each). The largest genera were Euphorbia (6 spp.), Cyperus, Eragrostis and Solanum (5 spp. each), Mollugo, Heliotropium and Cenchrus (4 spp. each), Acacia, Prosopis, Tephrosia, Corchorus, Boerhavia and Ziziphus (3 spp. each). This checklist consists of updated systematic families and plants names that will provide a useful starting point for further ecological and bioprospective research of the area under study. (author)

Obtaining Low Rank Coal Biotransforming Bacteria from Microhabitats Enriched with Carbonaceous Residues

International Nuclear Information System (INIS)

Valero Valero, Nelson; Rodriguez Salazar, Luz Nidia; Mancilla Gomez, Sandra; Contreras Bayona, Leydis

2012-01-01

Bacteria capable of low rank coal (LRC) biotransform were isolated from environmental samples altered with coal in the mine The Cerrejon. A protocol was designed to select strains more capable of LRC biotransform, the protocol includes isolation in a selective medium with LRC powder, qualitative and quantitative tests for LRC solubilization in solid and liquid culture medium. Of 75 bacterial strains isolated, 32 showed growth in minimal salts agar with 5 % carbon. The strains that produce higher values of humic substances (HS) have a mechanism of solubilization associated with pH changes in the culture medium, probably related to the production of extracellular alkaline substances by bacteria. The largest number of strains and bacteria with more solubilizing activity on LRC were isolated from sludge with high content of carbon residue and rhizosphere of Typha domingensis and Cenchrus ciliaris grown on sediments mixed with carbon particles, this result suggests that obtaining and solubilization capacity of LRC by bacteria may be related to the microhabitat where the populations originated.

NEW CONTRIBUTION TO THE STUDY OF ALIEN FLORA IN ROMANIA

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SÎRBU CULIŢĂ

2011-12-01

Full Text Available In this paper, a number of seventeen alien plant species are presented, one of them being now for the first time reported in Romania (Sedum sarmentosum Bunge. Some species are mentioned for the first time in the flora of Moldavia (Aster novae-angliae L., Cenchrus incertus M. A. Curtis, Chenopodium pumilio R. Br., Fraxinus americana L., Lindernia dubia (L. Pennell, Petunia × atkinsiana D. Don, Solidago gigantea Aiton, Tagetes erecta L. or Transylvania (Kochia sieversiana (Pallas C. A. Mey., and some are reported from new localities (seven species. For each species, there are presented general data on the geographical origin, its distribution in Europe and worldwide, as well as its invasion history and current distribution in Romania. Some of these species manifest a remarkable spreading tendency, expanding their invasion area in Romania. Voucher specimens were deposited in the Herbarium of University of Agricultural Sciences and Veterinary Medicine Iaşi (IASI.

Rehabilitation with pasture after open-cut coal mining at three sites in the Bowen Coal Basin of Queensland

Energy Technology Data Exchange (ETDEWEB)

Coaldrake, J E

1978-03-01

Open-cut coal mining in the Bowen Coal Basin leaves piled heaps of overburden, chiefly of a clayey nature, that have high pH, high salinity, and low contents of phosphorus and nitrogen. It is likely that pastures of introduced sub- tropical species can be used as a first stage in rehabilitating these areas, and possibly to convert them into permanent grazing lands. In field experiments the grasses Cenchrus ciliaris cv. Biloela (Buffel grass), Chloris gayana cv. Pioneer (Rhodes grass) and Panicum maximum var. trichoglume cv. Petrie (green panic) all showed satisfactory establishment and growth at two sites out of three tested. There was a clear response to superphosphate, with 400 kg/ha proving better over a two-year period than 100 kg/ha. Responses to nitrogen (as ammonium sulphate and as ammonium nitrate) were variable, and there was no response to gypsum and manganese at the one site tested for them. Of three tropical legumes subjected to limited testing only leucaena leucocephala gave encouraging results.

Lead Concentrations in Soils and Some Wild Plant Species Along Two Busy Roads in Pakistan.

Science.gov (United States)

Khalid, Noreen; Hussain, Mumtaz; Young, Hillary S; Ashraf, Muhammad; Hameed, Mansoor; Ahmad, Rashid

2018-02-01

This study assessed the level of Pb in soil and five wild plant species (Calotropis procera, Datura alba, Parthenium hysterophorus, Cenchrus ciliaris and Ricinus communis) during all the four seasons. Two busy roads varying in age and traffic volume were selected i.e., Faisalabad-Sargodha road (FSR) and Pindi Bhattian to Lillah (M-2) in the Punjab, Pakistan. Results showed raised levels of Pb in both plants and soil samples along both roads. The range of Pb concentration in plants was 0.08-3.98 and 1.95-4.74 mg kg - 1 for soil. Higher Pb contamination was recorded along FSR road as compared to M-2. Among seasons, the higher Pb concentration was found during summer, probably due to very high temperature. Among all the plants studied, Calotropis procera accumulated the highest level (3.98 mg kg - 1 dry wt.) of Pb; Thus, it can be used as good biomonitor/phytoremediator at Pb contaminated areas.

Avaliação da eficiência de controle de plantas daninhas gramíneas do herbicida clethodim em algodoeiro herbáceo (Gossypium hirsutum var. latifolium Hutch. Evaluation of the efficiency on the control of gramineous weeds by the herbicide clethodim in a herbaceous cotton crop (Gossypium hirsutum var. latifolium Hutch.

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J.P. Laca-Buendia

1992-01-01

Full Text Available Com o objetivo de conhecer a eficiência do herbicida clethodim no controle de plantas daninhas gramíneas e seu comportamento seletivo na cultura do algodão, cv. IAC-20, foi instalado um experimento em solo aluvial de textura arenosa. Foram estudados os seguintes tratamentos: clethodim + óleo mineral nas doses de 0,84 0,96 e 0,108 kg/ha + 0,5 % v/v, sethoxydim + óleo mineral a 0,23 kg/ha + 0,5% v/v em pós-emergência, alachlor a 2,4 kg/ha em pós-emergência, trifluralin a 0,89 kg/ha em pós-plantio incorporado, uma testemunha capinada e outra sem capina. As espécies de plantas daninhas mais freqüentes foram: Cenchrus echinatus L. (capim-carrapicho, Eleusine indica (L. Gaertn. (capim-pé-de-galinha e Brachiaria plantaginea (Link. Hitch. (capim-marmelada. Nenhum dos herbicidas testados apresento injúria à cultura. Quanto à produção, esses herbicidas apresentaram diferenças significativas em relação à testemunha capinada (828 kg/ha, sendo que o tratamento com clethodim + óleo mineral a 0,108 kg/ha + 0,5% v/v (528 kg/ha foi o único que apresentou diferenças significativas com a testemunha sem capina (330 kg/ha. Na altura da planta, a testemunha capinada somente apresentou diferenças significativas em relação ao tratamento com trifluralin e a testemunha sem capina. O carrapicho-de-burro e o capim-pé-de-galinha foram eficientemente controlados pelo clethodim + óleo mineral, em todas as doses estudadas, e sethoxydim + óleo mineral, com controle acima de 80% aos 45 dias da aplicação. O capim-marmelada foi eficientemente controlado pelo clethodim + óleo mineral a 0,096 e 0,108 kg/ha + 0,5% v/v, com 86% e 94%, respectivamente, seguido de sethoxydim + óleo mineral com 83%, e trifluralin com 71% de controle, até 45 dias após aplicação. O total de gramíneas foi eficientemente controlado pelo clethodim + óleo mineral 0,108 kg/ha + 0,5% v/v com 94,2% seguido de clethodim + óleo mineral 0,096 kg/ha + 0,5% v/v, com 85% e

Buffel grass (Cenchrus ciliaria L.) substitution for orange pulp on intake, digestibility, and performance of hairsheep lambs.

Science.gov (United States)

Macías-Cruz, Ulises; Quintero-Elisea, Juan A; Avendaño-Reyes, Leonel; Correa-Calderón, Abelardo; Alvarez-Valenzuela, Francisco D; Soto-Navarro, S A; Lucero-Magaña, F A; González-Reyna, Arnoldo

2010-02-01

Twenty Dorper x Pelibuey male lambs were used to evaluate the effect of substitution of forage with fresh orange pulp (FOP) in diets for fattening lambs on productive behavior, nutrient intake, apparent digestibility coefficient, and feeding costs. Lambs were divided into five groups (n = 4) and then housed in individual pens during 70 d. Treatments consisted of five levels of FOP (0, 25, 50, 75 and 100%) which substituted buffel grass hay on the base diet (40:60%, forage:concentrate). Additionally, changes in chemical composition of FOP stored in stack during 8 d were evaluated (from the day 1 until day 8). Daily feed intake expressed as kg/day and % live weight, lamb growth rate, feeding cost of each lamb per day and per fattening period, hemicellulose intake, and DM, OM, CP, NDF and hemicellulose digestibility showed a quadratic effect (P 0.05) among storage days. Therefore, replacing around 75% of buffel grass hay with FOP in diets for fattening lambs resulted in the best growth rate and more efficient diet utilization. Fresh orange pulp stored in a stack did not change its chemical composition, and did not affect its utilization as a sheep feedstuff.

Efeito do espaçamento entre fileiras de amendoim rasteiro na interferência de plantas daninhas na cultura Effect of peanut crop row spacing on weed interference in the culture

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T.C.S. Dias

2009-06-01

Full Text Available Objetivou-se com este trabalho avaliar o efeito da redução do espaçamento entre fileiras nos períodos de interferência e na produtividade do amendoim rasteiro (Arachis hypogaea. O experimento foi instalado no município de Jaboticabal-SP. Os tratamentos constaram de dois espaçamentos entre fileiras (80 e 90 cm, divididos em dois grupos. No primeiro, as plantas daninhas foram controladas desde a emergência até 0 (interferência constante, 30, 45, 60, 82, 97 e 112 dias depois. No segundo, as plantas daninhas conviveram com a cultura pelos mesmos períodos do grupo anterior. O delineamento experimental adotado foi o de blocos casualizados, em arranjo de parcelas subdivididas, com quatro repetições. As principais plantas daninhas presentes na área foram Digitaria sp., Xanthium strumarium, Acanthospermum hispidum e Cenchrus echinatus. Para uma perda tolerável de 5% de produtividade, o período crítico de prevenção à interferência foi dos 27 aos 76 e dos 35 aos 96 dias após a emergência para os espaçamentos de 80 e 90 cm, respectivamente; a queda de produtividade das parcelas mantidas com interferência de plantas daninhas em relação àquelas no limpo foi superior a 80%, independentemente do espaçamento.The aim of this research was to evaluate the effect of reducing the spacing between rows in periods of weed interference and peanut (Arachis hypogaea yield. The experiment was carried out in Jaboticabal, Brazil. Treatments consisted of two row spacings (80 to 90 cm, divided into two groups. In the first group, the weeds were controlled since emergence up to 0 (constant interference, 30, 45, 60, 82, 97 and 112 days. In the second group, the weeds were allowed to grow with the peanut culture during the same periods. The experiment was arranged in a randomized block design with treatments in split-plots, with four repetitions. The main weeds in the area were Digitaria sp., Xanthium strumarium, Acanthospermum hispidum and Cenchrus

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

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D.F. Biffe

2010-01-01

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

Atividade relativa da catalase de losna-branca (Parthenium hysterophorus comparada à de outras espécies daninhas Catalase relative activity of ragweed (Parthenium hysterophorus compared to that of other weed species

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S.J.P. Carvalho

2012-06-01

Full Text Available Este trabalho foi desenvolvido com o objetivo de avaliar a atividade relativa da catalase em extrato aquoso de losna-branca (Parthenium hysterophorus, bem como comparála à atividade da catalase de outras espécies daninhas. O trabalho constou de três fases, que envolveram a padronização do método, comparação da atividade relativa da catalase de plantas da família Asteraceae e comparação com outras 11 espécies daninhas, sendo estas: Euphorbia heterophylla, Alternanthera tenella, Cenchrus echinatus, Panicum maximum, Amaranthus viridis, Ipomoea hederifolia, Galinsoga parviflora, Bidens pilosa, Sonchus oleraceus, Cyperus rotundus e Commelina benghalensis. Observou-se resposta linear crescente da reação entre extrato aquoso de losna-branca e peróxido de hidrogênio, em razão da concentração do extrato vegetal. Em todas as fases, a atividade relativa da catalase de extrato de losna-branca foi superior à atividade da catalase das demais espécies daninhas. Com os dados obtidos nas três fases, conclui-se que a maior atividade relativa observada para a catalase da losnabranca contribui significativamente para a tolerância dessa espécie ao herbicida paraquat. Essa maior atividade pode ser consequência da maior concentração enzimática nas células ou devido à maior atividade intrínseca da enzima (afinidade enzima-substrato, havendo necessidade de estudos mais precisos para essa conclusão.This work was carried out to evaluate catalase relative activity of ragweed (Parthenium hysterophorus aqueous extract, as well as to compare it with catalase activity of other weed species. It consisted of three phases, involving method standardization, comparison of the catalase relative activity in Asteraceae family plants and that of ragweed catalase activity with the following 11 weed species: Euphorbia heterophylla, Alternanthera tenella, Cenchrus echinatus, Panicum maximum, Amaranthus viridis, Ipomoea hederifolia, Galinsoga parviflora

Cultivo in vitro de anteras como estrategia para el mejoramiento genético de buffelgrass (Cenchrus ciliaris L)

OpenAIRE

Carloni, Edgardo José

2016-01-01

Tesis (Doctor en Ciencias Agropecuarias)--UNC- Facultad de Ciencias Agropecuarias, 2016. Buffelgrass es una gramínea forrajera que se reproduce principalmente por apomixis. El objetivo del presente trabajo es generar variabilidad genética, mediante cultivo in vitro, en caracteres asociados a tolerancia a sequía a partir de germoplasma introducido de buffelgrass, con la finalidad de incorporarla en un programa de mejoramiento genético de esta especie....

Cereals for the semi-arid tropics

International Nuclear Information System (INIS)

De Wet, J.M.J.

1989-01-01

The region of semi-arid tropics is the most famine prone area of the world. This region with nearly one billion people extends across some 20 million square kilometres. Major domesticated cereals adapted to semi-arid regions are sorghum (Sorghum bicolor (L.) Moench), foxtail millet (Setaria italica (L.) P. Beauv.) and pearl millet (Pennisetum glaucum (L.) R. Br.). Several minor cereals are grown as speciality crops, or harvested in the wild in times of severe drought and scarcity. Important in the African Sahel are the fonios Digitaria iburua Stapf, D. exilis (Kapist) Stapf and Brachiaria deflexa (Schumach). C.E. Hubbard. These species are aggressive colonizers and are commonly encouraged as weeds in cultivated fields. Sown genotypes differ from their close wild relatives primarily in the lack of efficient natural seed dispersal. The fonios lend themselves to rapid domestication. Several wild cereals extend well beyond the limits of agriculture into the Sahara. Commonly harvested are the perennial Stipagrostis pungens and Panicum turgidum, and the annual Cenchrus biflorus (kram-kram). Kram-kram yields well under extreme heat and drought stress, and holds promise as a domesticated cereal. Sauwi millet (Panicum sonorum) is promising cereal in arid northwestern Mexico. (author). 31 refs

Manejo de plantas daninhas na cultura do algodoeiro com S-metolachlor e trifloxysulfuron-sodium em sistema de plantio convencional Weed Management with S-metolachlor and trifloxysulfuron-sodium in cotton field

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R.S. Freitas

2006-06-01

Full Text Available Objetivou-se com este trabalho desenvolver tecnologia para manejo de plantas daninhas na cultura do algodoeiro, em sistema de plantio convencional, combinando os herbicidas S-metolachlor em pré-emergência com trifloxysulfuron-sodium em pós-emergência. Foram avaliados 14 tratamentos, em arranjo fatorial 3 x 4 (três doses de S-metolachlor: 384, 768 e 1.152 g ha-1 e quatro doses de trifloxysulfuron-sodium: 0,0; 2,625; 5,250; e 7,875 g ha-1, mais duas testemunhas (com e sem convivência com as plantas daninhas por todo o ciclo do algodoeiro, em delineamento de blocos casualizados, com quatro repetições. Na área, foi verificada a presença das seguintes espécies daninhas: Alternanthera tenella, representando mais de 80% do total, Bidens spp., Acanthospermum hispidum, Cenchrus echinatus, Digitaria horizontalis, Eleusine indica e Commelina benghalensis. S-metolachlor apresentou alta eficiência no controle de A. tenella, C. echinatus, D. horizontalis, E. indica e C. benghalensis. Trifloxysulfuron-sodium controlou as espécies dicotiledôneas eficientemente. Os tratamentos que proporcionaram melhor produtividade de algodão em caroço foram Smetolachlor (768 g ha-1 mais trifloxysulfuron-sodium (7,875 g ha-1 e S-metolachlor (1.152 g ha-1 mais trifloxysulfuron-sodium (5,250 e 7,875 g ha-1. O melhor controle de plantas daninhas na colheita do algodão foi obtido com 1.152 g ha-1 de S-metolachlor mais 7,875 g ha-1 de trifloxysulfuron-sodium.This work aimed to develop a strategy for weed management in conventionally tilled cotton by combining the herbicides S-metolachlor in pre-emergence and trifloxysulfuron-sodium in post-emergence. Fourteen treatments were evaluated arranged in a factorial scheme 3 (three doses of S-metolachlor 384; 768 and 1,152 g ha-1 x 4 (four doses of trifloxysulfuron-sodium 0.0; 2.625; 5.250 and 7.875 g ha-1, plus two controls (with and without weeds throughout the cotton planting cycle. The following weed species were

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

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Sebastião Venâncio Martins

2008-12-01

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

Digestibility of Buffel grass (Cenchrus ciliaris)-based diets supplemented with four levels of Gliricidia sepium hay in hair sheep lambs

DEFF Research Database (Denmark)

Avilés-Nieto, Jonathan N.; Valle-Cerdán, José L.; Castrejón-Pineda, Francisco

2013-01-01

The objective of this experiment was to evaluate the effect of supplementing increasing levels of Gliricidia sepium hay (GS) with different levels of inclusion of Buffel grass (BG) hay on digestibility by hair sheep lambs (2.5 to 3.5 months of age). Eight male lambs were used in a replicated 4 × 4...... were not affected by treatments. The intake of crude protein (CP), organic matter (OM), and gross energy was higher (P lambs fed with T4 diet than control. NDF and ADF digestibilities were higher (P

Contenido nutricional, digestibilidad y rendimiento de biomasa de pastos nativos que predominan en las cuencas ganaderas de Molinopampa, Pomacochas y Leymebamba, Amazonas, Perú

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Manuel Oliva

2015-01-01

Full Text Available El objetivo del presente trabajo de investigación consistió en analizar el contenido nutricional, digestibilidad in vitro y el rendimiento de biomasa de las especies y según los ganaderos son las especies de pastos nativos más importantes que predominan en las tres principales cuencas ganaderas del departamento de Amazonas: Molinopampa, Pomacochas y Leymebamba. Se muestrearon al azar, seis áreas de 0,25 m2 por tratamiento cada 60 días durante tres brotes. Las muestras obtenidas fueron mezcladas y pesadas por separado, para luego extraer una alícuota homogénea y representativa de 1 kg por especie, para ser deshidrato en una estufa a 60 °C por 48 horas, las mismas fueron sometidas a un análisis proximal. Con los valores obtenidos de cada uno de los parámetros de evaluación y luego de ser multiplicados con sus respectivos valores ponderados se calculó el valor acumulativo final siendo los resultados las siguientes Trifolium repens L (35,9, Philoglossa mimuloides-Siso menudo (35,3, Cenchrus clandestinus (32,8, Trifolium dubium (32,5 y Philoglossa mimuloides-Siso lapacho (31,3. Los valores significan la importancia acumulativa de cada especie.

Forecasting an invasive species’ distribution with global distribution data, local data, and physiological information

Science.gov (United States)

Jarnevich, Catherine S.; Young, Nicholas E.; Talbert, Marian; Talbert, Colin

2018-01-01

Understanding invasive species distributions and potential invasions often requires broad‐scale information on the environmental tolerances of the species. Further, resource managers are often faced with knowing these broad‐scale relationships as well as nuanced environmental factors related to their landscape that influence where an invasive species occurs and potentially could occur. Using invasive buffelgrass (Cenchrus ciliaris), we developed global models and local models for Saguaro National Park, Arizona, USA, based on location records and literature on physiological tolerances to environmental factors to investigate whether environmental relationships of a species at a global scale are also important at local scales. In addition to correlative models with five commonly used algorithms, we also developed a model using a priori user‐defined relationships between occurrence and environmental characteristics based on a literature review. All correlative models at both scales performed well based on statistical evaluations. The user‐defined curves closely matched those produced by the correlative models, indicating that the correlative models may be capturing mechanisms driving the distribution of buffelgrass. Given climate projections for the region, both global and local models indicate that conditions at Saguaro National Park may become more suitable for buffelgrass. Combining global and local data with correlative models and physiological information provided a holistic approach to forecasting invasive species distributions.

Abundance of food plant species and food habits of Rhinoceros unicorns Linn. in Pobitora Wildlife Sanctuary, Assam, India

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P. Konwar

2009-09-01

Full Text Available Food habits and abundance of food plant species of Rhinoceros unicornis in Pobitora Wildlife Sanctuary were studied from January 1999 through December 2001. Totally 32 numbers of Rhino food plants were identified, of which 15 were grasses, four shrubs, five aquatic hydrophytes and eight tree species (21 terrestrial and 11 aquatic. During the dry season, the Rhino feeds on almost 90% food items from Hemarthria compressa, Arundo donax, Phragmites karka, Cerex rubro-brumee etc. The other short grasses such as Cynodon dactylon, Andropogon ssp., Cenchrus ciliaris, Chrysopogon aciculatus and tender and young shoots and twigs of Schelristechya fuesche, Saccharum spontaneum, Lagerstroemia flosreginae etc. are consumed in limited portions. The rhino consumes 11 cultivated crops and vegetables, viz., Ricinus communis, Oryza sativa, Solanum melongena, Lycopersicon esculentum, Solanum tuberosum, Brassica nigra, Luffa cylindrica, Luffa acutangula, Cucurbita moschata, Cucumis sativus and Ipomoea batatas etc. Highest density of food plant species observed in the study area were Cynodon dactylon (167.5/m2, Hemarthria compressa (73.75/m2, Vetiveria zizanioides (56/m2, Saccharum ravannae (51.5/m2, Pharagmites karka (50.75/m2, Leersia hexandra (46.75/m2, Brachiarea pseudointerrupta (40/m2 and Eichhornia crassipes (35/m2.

Production et coûts des semences utilisées pour l'amélioration des jachères et des aménagements antiérosifs : "Le cas des zones de savane du Nord Cameroun"

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Dugué, P.

1999-01-01

Full Text Available Seeds Production for Fallow and Anti-Erosion Management : "The Case of the Savannah Areas in North Cameroon". The maintenance of cultivated soils' fertility in North Cameroon relies on the extension of the techniques of water erosion control and improved legume crop fallows. These innovations require that seeds must become available to farmers. These seeds are legume seeds (Calopogonium mucunoides, Stylosanthes hamata, Mucuna pruriens, Cajans cajan or perennial grasses (Panicum maximum, Andropogon gayanus, Cenchrus ciliaris. On station research has developed the techniques of seeds production which can be introduced in the farmer's environment on the one hand, and on the other hand can be used to evaluate the cost of legumes seeds production. Depending on the species, the total price of seeds production varies from 250 to 1160 FCFA/kg (0, 5 U$ to 2 U$/kg. Based on these prices, it seems possible in the first step to diffuse these seeds varieties. The diffusion of the vegetal material depends firstly on the interest that farmers attach to techniques of soil restauration which are proposed to them. If they adopt these innovations, they can easily produce seeds that they need after been trained to the techniques developed by research.

Tackling Contentious Invasive Plant Species: A Case Study of Buffel Grass in Australia

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Grice, Anthony C.; Friedel, Margaret H.; Marshall, Nadine A.; van Klinken, Rieks D.

2012-02-01

Introduced plants that have both production values and negative impacts can be contentious. Generally they are either treated as weeds and their use prohibited; or unfettered exploitation is permitted and land managers must individually contend with any negative effects. Buffel grass ( Cenchrus ciliaris) is contentious in Australia and there has been no attempt to broadly and systematically address the issues surrounding it. However, recent research indicates that there is some mutual acceptance by proponents and opponents of each others' perspectives and we contend that this provides the basis for a national approach. It would require thorough and on-going consultation with stakeholders and development of realistic goals that are applicable across a range of scales and responsive to regional differences in costs, benefits and socio-economic and biophysical circumstances. It would be necessary to clearly allocate responsibilities and ascertain the most appropriate balance between legislative and non-legislative mechanisms. A national approach could involve avoiding the introduction of additional genetic material, countering proliferation in regions where the species is sparse, preventing incursion into conservation reserves where it is absent, containing strategically located populations and managing communities to prevent or reduce dominance by buffel grass. This approach could be applied to other contentious plant species.

Comparative gene expression in sexual and apomictic ovaries of Pennisetum ciliare (L.) Link.

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Vielle-Calzada, J P; Nuccio, M L; Budiman, M A; Thomas, T L; Burson, B L; Hussey, M A; Wing, R A

1996-12-01

Limited emphasis has been given to the molecular study of apomixis, an asexual method of reproduction where seeds are produced without fertilization. Most buffelgrass (Pennisetum ciliare (L.) Link syn = Cenchrus ciliaris L.) genotypes reproduce by obligate apomixis (apospory); however, rare sexual plants have been recovered. A modified differential display procedure was used to compare gene expression in unpollinated ovaries containing ovules with either sexual or apomictic female gametophytes. The modification incorporated end-labeled poly(A)+ anchored primers as the only isotopic source, and was a reliable and consistent approach for detecting differentially displayed transcripts. Using 20 different decamers and two anchor primers, 2268 cDNA fragments between 200 and 600 bp were displayed. From these, eight reproducible differentially displayed cDNAs were identified and cloned. Based on northern analysis, one cDNA was detected in only the sexual ovaries, two cDNAs in only apomictic ovaries and one cDNA was present in both types of ovaries. Three fragments could not be detected and one fragment was detected in ovaries, stems, and leaves. Comparison of gene expression during sexual and apomictic development in buffelgrass represents a new model system and a strategy for investigating female reproductive development in the angiosperms.

Biocontrol Ability of Puccinia abrupta var. partheniicola on Different Growth Stages of Parthenium Weed (Parthenium hysterophorus L.

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MOHAMAD TAUFIK FAUZI

2009-09-01

Full Text Available A research was conducted to investigate the biological control ability of Puccinia abrupta var. partheniicola infected to parthenium weed (Parthenium hysterophorus L. at different stages of growth in a glasshouse. The study also investigated the combined effect of the infection and the competitor plant, i.e. buffel grass (Cenchrus ciliaris L., a pasture species usually found in the weed habitat in Central Queensland. The 2 × 3 factorial experiment was arranged in a completely randomized design with six replicates in each treatment. The parthenium weeds were planted with or without buffel grass. The plants were inoculated with P. abrupta var. partheniicola urediniospores either at the rosette, flowering or mature growth stage of development. As controls, an additional six non inoculated plants with and without buffel grass were planted. The results showed that P. abrupta var. partheniicola affected more on the younger plants than on the older ones. Its infection decreased the plant height. A higher reduction in plant above ground biomass was recorded because of the rust when the plants were inoculated at the rosette growth stage of development in the presence of competition. The impact of the rust was greatest on the ability of parthenium to produce seeds.

UAVs and Machine Learning Revolutionising Invasive Grass and Vegetation Surveys in Remote Arid Lands

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Juan Sandino

2018-02-01

Full Text Available The monitoring of invasive grasses and vegetation in remote areas is challenging, costly, and on the ground sometimes dangerous. Satellite and manned aircraft surveys can assist but their use may be limited due to the ground sampling resolution or cloud cover. Straightforward and accurate surveillance methods are needed to quantify rates of grass invasion, offer appropriate vegetation tracking reports, and apply optimal control methods. This paper presents a pipeline process to detect and generate a pixel-wise segmentation of invasive grasses, using buffel grass (Cenchrus ciliaris and spinifex (Triodia sp. as examples. The process integrates unmanned aerial vehicles (UAVs also commonly known as drones, high-resolution red, green, blue colour model (RGB cameras, and a data processing approach based on machine learning algorithms. The methods are illustrated with data acquired in Cape Range National Park, Western Australia (WA, Australia, orthorectified in Agisoft Photoscan Pro, and processed in Python programming language, scikit-learn, and eXtreme Gradient Boosting (XGBoost libraries. In total, 342,626 samples were extracted from the obtained data set and labelled into six classes. Segmentation results provided an individual detection rate of 97% for buffel grass and 96% for spinifex, with a global multiclass pixel-wise detection rate of 97%. Obtained results were robust against illumination changes, object rotation, occlusion, background cluttering, and floral density variation.

Apomixis y su importancia en la selección y mejoramiento de gramineas forrajeras tropicales. Revisión

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Adrián R. Quero Carrillo

2010-01-01

Hyparrhenia, Melinis, Panicum, Paspalum, Pennisetum, Setaria, Tripsacum y Urochloa, entre otros. Las especies apomícticas contienen individuos diploides y poliploides conformando "complejos agámicos", donde las barreras reproductivas quedan delimitadas por la apomixis y el nivel de ploidía, lo que tiene impacto en su aprovechamiento. Individuos diploides mantienen la sexualidad activa y estos son raros fuera del centro de origen de especie. Los individuos poliploides son apomícticos y los individuos sexuales poliploides pueden inducirse en el laboratorio, lo que permite obtener descendencia híbrida. La riqueza genética, originada del centro de diversidad es la base para superar problemas productivos y de estabilidad ecológica: producción durante la sequía, fijación de nitrógeno, calidad, resistencia a plagas y enfermedades; como se ha demostrado en casos exitosos en Brachiaria, Panicum y Cenchrus. Los avances en investigación sobre apomixis han elucidado su biología y diversas técnicas para su manejo. Sin embargo, el impacto de estos avances en la investigación sobre forrajes en México, promueve la recapitulación sobre el aprovechamiento de recursos genéticos y el interés en la generación de híbridos para las necesidades de producción en pastoreo extensivo en México.

Perennial pastures for marginal farming country in southern Queensland. 2. Potential new grass cultivar evaluation

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Richard G. Silcock

2015-01-01

Full Text Available Trials in the Condamine-Balonne basin, Australia, compared 11 promising perennial pasture grass accessions (4 Bothriochloa, 2 Cenchrus, 2 Urochloa and 1 each of Digitaria, Eragrostis and Panicum species against the best similar commercial cultivars on the basis of ease of establishment from seed, persistence once established, forage yield and ease of seed production.  Accessions sown at a site were determined by prior experience with them on a range of soils.  High quality seed was relatively easy to produce for both Urochloa species and for Eragrostis curvula CPI 30374 but problematic for the Bothriochloa spp.  Once established, all accessions persisted for 3–5 years and most were well grazed, but adequate establishment was sometimes a problem with Panicum stapfianum and Bothriochloa ewartiana.  The dry matter yield ratings of the non-commercial lines were similar to those of the commercial equivalents of the same species.  While agronomically valuable, none of the promising new grasses was considered worthy of commercialization at this point because their strengths did not warrant the setting up of a seed-production business in competition with current commercial enterprises.  Long-standing cultivars such as Gayndah buffel and Nixon sabi grass continued to exhibit their superior pasture qualities.Keywords: Herbicide tolerance, persistence, forage yield, establishment ease, commercialization, seed production.DOI: 10.17138/TGFT(315-26

Alleviation of heavy metals toxicity by the application of plant growth promoting rhizobacteria and effects on wheat grown in saline sodic field.

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Hassan, Tamoor Ul; Bano, Asghari; Naz, Irum

2017-06-03

The aim of the study was to determine tolerance of plant growth promoting rhizobacteria (PGPR) in different concentrations of Cu, Cr, Co, Cd, Ni, Mn, and Pb and to evaluate the PGPR-modulated bioavailability of different heavy metals in the rhizosphere soil and wheat tissues, grown in saline sodic soil. Bacillus cereus and Pseudomonas moraviensis were isolated from Cenchrus ciliaris L. growing in the Khewra salt range. Seven-day-old cultures of PGPR were applied on wheat as single inoculum, co-inoculation and carrier-based biofertilizer (using maize straw and sugarcane husk as carrier). At 100 ppm of Cr and Cu, the survival rates of rhizobacteria were decreased by 40%. Single inoculation of PGPR decreased 50% of Co, Ni, Cr and Mn concentrations in the rhizosphere soil. Co-inoculation of PGPR and biofertilizer treatment further augmented the decreases by 15% in Co, Ni, Cr and Mn over single inoculation except Pb and Co where decreases were 40% and 77%, respectively. The maximum decrease in biological concentration factor (BCF) was observed for Cd, Co, Cr, and Mn. P. moraviensis inoculation decreases the biological accumulation coefficient (BAC) as well as translocation factor (TF) for Cd, Cr, Cu Mn, and Ni. The PGPR inoculation minimized the deleterious effects of heavy metals, and the addition of carriers further assisted the PGPR.

Grass and forb species for revegetation of mixed soil-lignite overburden in East Central Texas

Energy Technology Data Exchange (ETDEWEB)

Skousen, J.G.; Call, C.A. (West Virginia University, Morgantown, WV (USA). Division of Plant and Soil Sciences)

Ten grasses and seven forbs were seeded into mixed soil-lignite overburden in the Post Oak Savannah region of Texas and monitored for establishment and growth over a 3-year period without fertilization. Buffelgrass (Cenchrus ciliaris), green sprangletop (Leptochloa dubia), switchgrass (Panicum virgatum), and kleingrass (P. coloratum) developed monotypic stands with sufficent density, aerial cover, and aboveground biomass to stabilize the mixed soil-lignite overburden surface by the end of the first growing season. Plant mortality eliminated buffelgrass and green sprangletop stands by the end of the third growing season. Indiangrass (Sorghastrum nutans) developed a satisfactory stand by the end of the third growing season, while Oldworld bluestem (Bothriochloa X Dicanthium), yellow bluestem (Bothriochloa ischaemum), and sideoats grama (Bouteloua curtipendula) established at a slower rate. Cover and biomass measurements from an adjacent, unfertilized stand of Coastal bermudagrass (Cynodon dactylon) were compared with those of seeded grasses throughout the study. Partidge pea (Cassia fasciculata) established rapidly and had the greatest cover and biomass of all seeded forbs by the end of the first growing season. Sericea lespedeza (Lespedeza cuneata), Illinois bundleflower (Desmanthus illinoensis), and western indigo (Indigofera miniata) developed adequate stands for surface stabilization by the end of the third growing season, while faseanil indigo (Indigofera suffruticosa), virgata lespedeza (Lespedeza virgata), and awnless bushsunflower (Simsia calva) showed slower establishment. 27 refs., 3 tabs.

Chloromonilinic Acids C and D, Phytotoxic Tetrasubstituted 3-Chromanonacrylic Acids Isolated from Cochliobolus australiensis with Potential Herbicidal Activity against Buffelgrass (Cenchrus ciliaris).

Science.gov (United States)

Masi, Marco; Meyer, Susan; Clement, Suzette; Pescitelli, Gennaro; Cimmino, Alessio; Cristofaro, Massimo; Evidente, Antonio

2017-10-27

The fungal pathogen Cochliobolus australiensis isolated from infected leaves of the invasive weed buffelgrass (Pennisetum ciliare) was grown in vitro to evaluate its ability to produce phytotoxic metabolites that could potentially be used as natural herbicides against this weed. Two new tetrasubstituted 3-chromanonacrylic acids, named chloromonilinic acids C (1) and D (2), were isolated from the liquid cultures of C. australiensis, together with the known chloromonilinic acid B. Chloromonilinic acids C and D were characterized by spectroscopic and chemical methods as (E)-3-chloro-3-[(5-hydroxy-3-(1-hydroxy-2-methoxy-2-oxoethyl)-7-methyl-4-oxo-4H-chromen-2-yl)]acrylic acid and (Z)-3-chloro-3-[(5-hydroxy-3-(2-methoxy-2-oxoethyl)-7-methyl-4-oxo-4H-chromen-2-yl)]acrylic acid, respectively. The stereochemistry of chloromonilinic acids C and D was determined using a combination of spectroscopic and computational methods, including electronic circular dichroism. The fungus produced these compounds in two different liquid media together with cochliotoxin, radicinin, radicinol, and their 3-epimers. The radicinin-related compounds were also produced when the fungus was grown in wheat seed solid culture, but chloromonilinic acids were not found in the solid culture organic extract. All three chloromonilinic acids were toxic to buffelgrass in a seedling elongation bioassay, with significantly delayed germination and dramatically reduced radicle growth, especially at a concentration of 5 × 10 -3 M.

Períodos de interferência das plantas daninhas em algodoeiro de fibra colorida 'BRS Safira' Weeds interference periods in naturally colored cotton 'BRS Safira'

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Gleibson Dionízio Cardoso

2010-09-01

Full Text Available Objetivou-se com esse trabalho, identificar os períodos de interferência das plantas daninhas no algodoeiro de fibra colorida (BRS Safira, bem como avaliar a comunidade infestante nesta cultura. O experimento foi realizado no município de Missão Velha, CE, região do Cariri, na safra 2007/2008. Utilizou-se o delineamento experimental em blocos ao acaso, com quatro repetições, em esquema fatorial 2 x 5, sendo os fatores: modalidades de competição (com e sem competição de plantas daninhas e período de interferência das plantas daninhas. A comunidade infestante foi avaliada por meio de dois índices fitossociológicos (Dominância relativa e Importância relativa. Os períodos iniciais de controle ou de convivência após a emergência da cultura foram 0-20; 0-40; 0-60; 0-80 dias após a emergência (DAE e 0-colheita. Os períodos de interferência foram determinados considerando-se perdas na produtividade de 2; 5 e 10%; realizando-se análise de regressão pelo modelo sigmoidal de Boltzman, utilizando-se os dados de produtividade para cada modalidade de competição. Dentre as 21 espécies observadas na comunidade infestante, destacaram-se: Richardia grandiflora, Amaranthus deflexus, Eleusine indica, Merremia aegyptia, Eragrotis pilosa, Cenchrus echinatus e Waltheria indica. Os períodos críticos anteriores à interferência foram, respectivamente, 8; 14 e 20 DAE, para perdas na produtividade de 2; 5 e 10%; e os períodos críticos de prevenção a interferências, foram, respectivamente, 100; 82 e 60 dias.This study aimed to determine the late-season presence of weeds in reddish brown cotton (cultivar BRS Safira and the critical times for removing weeds. The experiment was carried out in the area of Embrapa in Missão Velha-CE, Brazil, located at 7º42'07" S latitude and 39º24'18" WGr. longitude, during the 2007/2008 season. The treatments consisted of two control groups: weed-free crop during the initial period after crop emergency

Eficácia e seletividade de herbicidas do grupo das imidazolinonas aplicados em pós-emergência de plantas daninhas monocotiledôneas na cultura do girassol CL Efficacy and selectivity of herbicides from the imidazolinone group applied in post-emergence of monocotyledon weeds on CL sunflower culture

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A.C. Francischini

2012-12-01

Full Text Available O controle das plantas daninhas, em geral, é realizado pelo uso de herbicidas, porém essa prática é limitada na cultura do girassol, por haver apenas dois produtos registrados para essa cultura (alachlor e trifluralin. Entretanto, o uso de novas tecnologias pode facilitar o controle das plantas daninhas com herbicidas que possuem amplo espectro de controle. Assim, o objetivo deste trabalho foi avaliar a eficácia e seletividade de herbicidas do grupo das imidazolinonas aplicados em pós-emergência de plantas daninhas monocotiledôneas na cultura do girassol Clearfield (CL. Para isso, foram instalados dois experimentos em campo. Os tratamentos e as respectivas doses em g ha-1 foram: trifluralin (1.800 aplicado em pré-emergência, fluazifop-p-butil (187 e imazapic+imazapyr nas doses de [36,75+12,25], [52,5+17,5], [12,25+36,75] e [17,5+52,5], aplicados em pós-emergência, além de duas testemunhas sem aplicação de herbicida, sendo uma sem capina e outra com capina. Foram realizadas avaliações de controle para Eleusine indica, Brachiaria plantaginea, Lolium multiflorum, Digitaria insularis, Cenchrus echinatus e Digitaria horizontalis, fitointoxicação do girassol Clearfield, estande e produtividade em kg ha-1. De acordo com os resultados, verificou-se que o uso do sistema CLmostrou-se uma ótima opção para áreas com infestação de plantas daninhas monocotiledôneas, pois possibilita a aplicação de herbicidas inibidores da enzima acetolactato sintase (ALS, obtendo excelente controle das plantas daninhas, além de não provocar injúrias visuais, mantendo o estande inicial, sem alterar a produtividade da cultura.Weed control is generally accomplished by the use of herbicides. However, this practice is limited in sunflower cultivation,since only two products are registered for the culture (alachlor and trifluralin.The use of new technologies can facilitate weed control with herbicides with broad spectrum control. Therefore, the

The physical environment and major plant communities of the Karoo National Park, South Africa

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Francine Rubin

1996-08-01

Full Text Available The major plant communities of the Karoo National Park are described using the methods of the Zurich-Montpellier school of phytosociology, to assist with the formulation of a management strategy for the park. The vegetation physiognomy consists of Montane Karoo grassy shrublands. Karoo grassy dwarf shrublands. Karoo succulent dwarf shrublands and riparian thicket. Steep elevation and precipitation gradients within the study area have a direct impact on gradients in the vegetation. High elevation (1 800 m, and relatively high rainfall (406 mm montane grasslands occupy communities dominated by grasses (Merxmuellera disticha, Themeda triandra and woody species (Diospyros austro-africana, Elytropappus rhinocerotis, Euryops annae, Passerina montana. The increasing aridity away from the escarpment edge in a northerly direction is steep, and Montane Karoo dwarf shrublands replace these mesic communities. Species such as Eriocephalus ericoides, Rosenia oppositifolia and Pteronia tricephala dominate. At lower elevation (800 m the precipitation is very low (175 mm and uncertain (coefficient of variation of 78 . The substrata influence the vegetation, with the sandy substrata of the drainage lines supporting more woody taxa (Acacia karroo, Lycium cinereum and grasses (Hyparrhenia hirta, Stipagrostis namaquensis, Cenchrus ciliaris. Moving away from the mesic environment of the riparian zone, rapid desiccation occurs and the most xeric communities are encountered, dominated by Stipagrostis obtusa, S. ciliata and Pent-da incana. This document provides descriptions of the general communities and their associated landscape, lithology and soils.

Interactions among buffelgrass, phenanthrene and phenanthrene-degrading bacteria in gnotobiotic microcosms.

Science.gov (United States)

Robert, Francoise M; Sun, Wenhao H; Toma, Marisa; Jones, Ryan K; Tang, Chung-Shih

2008-07-15

An experiment was undertaken in gnotobiotic microcosms to determine the role of buffelgrass (Cenchrus ciliaris) and a phenanthrene-degrading bacterium (strain PM600) in the degradation of phenanthrene. The Gram-negative bacterium was identified as a Sphingomonas sp. by 16S rRNA gene sequence analysis and as S. paucimobilis by biochemical tests (API 20 NE strips). Its yellow pigment corresponded to nostoxanthin and its cellular fatty acids were typical of the genus Sphingomonas. Moreover, it was devoid of lipopolysaccharides. Strain PM600 was tested for growth on mineral medium supplemented with No. 2 diesel, hexadecane, mineral oil, pristane, phenanthrene, and pyrene as single carbon sources. It was capable of utilizing phenanthrene only. In the gnotobiotic microcosms silica sand was either or not supplemented with 150 mg of phenanthrene kg(-1) sand, inoculated with strain PM600, and planted to sterile young seedlings of buffelgrass. After 28 days, 67% of the reduction of the phenanthrene concentration was assigned to degradation by the bacterium and ca. 20% to abiotic factors. No statistically significant effect of the young buffelgrass was found. In the absence of phenanthrene, the bacterial population significantly increased in the rhizosphere of buffelgrass. However, in the presence of buffelgrass and phenanthrene, the bacterial population preferentially responded to phenanthrene. The growth of buffelgrass was severely curtailed by phenanthrene in the absence of the bacterium. However, strain PM600 effectively protected buffelgrass against the phytotoxicity of phenanthrene.

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

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A.L.L. Barroso

2010-01-01

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

The effects of soil fumigation on the growth and mineral nutrition of weeds and crops=Efeito da fumigação do solo no crescimento e nutrição mineral de plantas daninhas e culturas

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Marliane de Cássia Soares da Silva

2012-04-01

Full Text Available Weeds and soil microorganisms interact with each other in the soil/root interface, promoting the development and establishment of both. The objective of this study was to evaluate the growth and nutrient accumulation in eight species of weeds (Ageratum conyzoides L., Bidens pilosa L., Cenchrus echinatus L., Conyza bonariensis L., Echinochloa crus-galli L., Eleusine indica L. Ipomoea grandifolia L. and Lolium multiflorum L. and in bean and corn crops grown for 50 days in a substrate fumigated with methyl bromide. Assessments relating to the height, leaf area, leaf number, dry weight of shoots and roots and relative content of nutrients were carried out 50 days after seedling emergence. A positive effect of soil fumigation was observed on the growth, leaf number, leaf area, plant height and accumulation of nutrients in monocot weeds in relation to dicots. Conyza bonariensis was the most affected by soil fumigation, with levels of dry matter, leaf number, leaf area, height and accumulation of nutrients approximately 50% lower than plants grown in normal soil. Fumigation also influenced the growth cycle of the plants, which was lower for B. pilosa, E. indica and C. echinatus. We also observed a 20 and 30% lower phosphorus accumulation in Bidens pilosa and Conyza bonariensis, respectively, when grown in the sterilized soil. Overall, the bean and corn crops were less affected by soil fumigation than the weeds.Plantas daninhas e microrganismos do solo se interagem na interface solo/raiz promovendo vantagens para o desenvolvimento e estabelecimento de ambos. Objetivou-se com este trabalho avaliar o crescimento e o acúmulo de nutrientes em oito espécies de plantas daninhas (Ageratum conyzoides L., Bidens pilosa L., Cenchrus echinatus L., Conyza bonariensis L., Echinochloa crus-galli L., Eleusine indica L., Ipomoea grandifolia L. e Lolium multiflorum L. e nas culturas de feijão e milho, cultivadas, por 50 dias, em substrato fumigado com brometo de

Reproductive effort of some annual and perennial plant species: impact of successional sequence, habitat conditions and plant size

International Nuclear Information System (INIS)

Shaukat, S.; Khan, M.A.; Zaidi, S.; Siddiqui, M.F.; Khan, N.; Zafar, H.

2013-01-01

The reproductive effort of some annual and perennial plant species was investigated with respect to successional sequence, habitat conditions and plant size. in the psammosere succession (dune succession), the reproductive effort (RE) of Cressa cretica and A triplex griffithii was significantly greater in the early stage compared to that in late succession. Likewise, in relation to lithosere succession, Sporobolus arabicus. Pluchea lanceolata and Vernonia cenerescens all showed high reproductive effort in early part of succession compared to that of late succession. The annuals (S. arabicus and P lance/ala) exhibited greater reproductive effort compared to the perennial species Vernonia cinerescens. Examination of the Impact of site differences on reproductive effort showed that four grasses including Selaria intermedia, Chioris harbata, Cenchrus hiflorus, and Eragroslis pilosa were found to have significantly (P<0.05) greater reproductive effort in site 1 (near cultivated field), compared to site 2 (a vacant lot), which had low nutrient level compared to site 1. The reproductive effort of Sonclius asper (a composite) did not exhibit significant difference between sites. The investigation of relationships between plant size (volume) and reproductive effort of Solanuin forskalii, Senna holosericea and Heliolropium ophioglossum showed positive correlations between plant size and reproductive effort. Solanum forskalii and Senna holosericca, in particular, exhibited a close association in this respect. It is concluded that: 1) RE is greater in early compared to late succession, 2) RE changes with the habitat and 3) there seems to be a direct relationship between RE and plant size. (author)

Thal and technologies for fodder production

International Nuclear Information System (INIS)

Ali, Z.; Ahmad, M.; Haqqanni, A.M.

2005-01-01

The climate of the study area is arid and semi-arid subtropical, characterized by high summer- temperature (1200 F) with hot dry winds, frequent dust-storms and torrential and erratic rains. Winter is mild, with cold nights having temperature 320 F. The fodder tree species in arid and semi-arid regions are a valuable resource of feeding livestock in these regions during the lean periods of both winter and summer seasons. Fodder trees are properly looked after, not only for their usefulness for fuel and furniture, etc., but good environment would improve the quality of life, along with manifold higher fodder- production for animals. Fodder trees should be lopped only when they are about two to three meters in height and branches more than 7.5 cm thick should not be lopped. Lopping of the whole tree, as usually practiced, is injurious to trees and affects their vigor. Lopping cycle should be such that we get new leaves at the desired time of the year. It is recommended that; (i) proven grass-species, like Cenchrus ciliaris, Lasiurus sindicus, Pennisetum orientale and Panicum antidotale, be introduced in Thai, (ii) the improved varieties of some fodder-crops like oats, berseem, lucerne, sorghum sudan grass hybrid and mott grass being multicut (would cover the scarcity periods) can be introduced in the irrigated areas and (iii) the trees and shrub-species, such as Acacia tortilis, Zizyphus nummularia, Acacia anura, Prosopis cineraria, Acacia nilotica, Tacomella undulate, Zizyphus mauritiana, Calligonum polygonoides, Tamarax aphylla and Albizia lebbeck, can be propagated and promoted in Thai desert. (author)

Hyperspectral signature analysis of three plant species to long-term hydrocarbon and heavy metal exposure

Science.gov (United States)

Lassalle, Guillaume; Credoz, Anthony; Fabre, Sophie; Hédacq, Rémy; Dubucq, Dominique; Elger, Arnaud

2017-10-01

Recent studies aim to exploit vegetation hyperspectral signature as an indicator of pipeline leakages and natural oil seepages by detecting changes in reflectance induced by oil exposure. In order to assess the feasibility of the method at larger spatial scale, a study has been carried out in a greenhouse on two tropical (Cenchrus alopecuroides and Panicum virgatum) and a temperate (Rubus fruticosus) species. Plants were grown on contaminated soil during 130 days, with concentrations up to 4.5 and 36 g.kg-1 for heavy metals and C10-C40 hydrocarbons respectively. Reflectance data (350-2500 nm) were acquired under artificial light from 1 to 60 days. All species showed an increase of reflectance in the visible (VIS, 400-750 nm) and short-wave infrared (SWIR, 1300-2500 nm) under experimental contaminants exposure. However, the responses were contrasted in the near-infrared (NIR, 750-1300 nm). 47 normalized vegetation indices were compared between treatments, and the most sensitive to contamination were retained. Same indices showed significant differences between treatments at leaf and plant scales. Indices related to plant pigments, plant water content and red-edge reflectance were particularly sensitive to soil contamination. In order to validate the selection of indices, hyperspectral measurements were performed outdoor at plant scale at the end of the experiment (130 days). Leaf samples were also collected for pigment analysis. Index selected at day 60 were still sensitive to soil contamination after 130 days. Significant changes in plant pigment composition were also observed. This study demonstrates the interest of hyperspectral data for oil exploration and environmental diagnosis.

Current glimpse of airborne allergenic pollen in Indian subcontinent

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Kavita Ghosal

2015-12-01

Full Text Available Respiratory allergic diseases such as bronchial asthma, rhinitis, urticaria, atopic dermatitis have been steadily increasing all over the world, including India. Owing to its alarming trend, several aerobiological surveys have been undertaken in different parts of India to delineate the variety of pollen and spore load. In this review, we have reported the current state of aerobiological knowladge in India with particular reference to allergenic airborn pollen occurence in 2001–2015. Pollen have been found to contribute a significant proportion in the air and caused allergy symptoms in the local inhabitants. Aerobiological records, a questionnaire survey and hospitalization records have been employed for the analysis. Holoptelea integrifolia, Amaranthus spinosus in northern region, Sorghum vulgare, Pennisetum, Gynandropsis gynandra, Parthenium hysterophorus, Dolichandrone platycalyx in southern regions, and Parthenium hysterophorus from the western region; Cynodon dactylon, Cenchrus ciliaris in the central area; Acacia auriculiformis, Cleome gynandra, Catharanthus roseus, Phoenix sylvestris, Areca catechu, and Lantana camara in the eastern regions as potential aeroallergens in India. The statistical approach confirmed the correlation between hospitalization rate associated with allergy-related health troubles and the prevalent allergenic pollen in the air. The Poaceae group has been found to be dominant throughout India. Immuno-biochemical studies identified various protein with allergenic potential found in the pollen recorded. Epitope identification and homology of the major allergenic protein Cat r1 of Catharanthus sp and Par j 1 of Parietaria judaica have been found. Identification of allergenic pollen grains and the modern approach concerning cross-reactivity and epitope revelation of dominant airborne pollen have important clinical implications for the prevention, diagnosis and treatments of allergic diseases in India.

OCORRÊNCIA E ATIVIDADE DE BACTÉRIAS DIAZOTRÓFICAS EM FORRAGEIRAS CULTIVADAS NA REGIÃO SEMIÁRIDA NO BRASIL

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MÁRCIA CARNEIRO MONTEIRO DOS SANTOS

2013-01-01

Full Text Available Diazotrophic bacteria play important role on economy nitrogen fertilizer in forage glasses and environmental sustainability. With the objective of evaluate the occurrence of diazotrophic bacteria associated associated with native forage at two different times and identify isolates with potential for fixing N2 in the semiarid region. Was conducted in the Soil Laboratory of the Centro de Saúde e Tecnologia Rural in Federal University of Campina Grande, Campus de Patos, Paraíba. A study was carried out at the Soil Laboratory of the Centro de Saúde e Tecnologia Rural of the Federal University of Campina Grande, in Patos, Paraíba. The objective this study was to verify in the native diazotrophic endophytic bacteria associated with forage glasses and to identify isolates in NBF hability, during the rainy and dry seasons in semiarid region. Root samples of three forage grasses [Andropogon gayanus Kunth (Andropogon, Panicum maximum Jacq. cv. Tanzania (Tanzânia and Cenchrus ciliaris L. (Buffel] cultivated in the field experiment was utilized. The bacteria were isolated in NFb culture media free-N specific for Azospirillum spp., the isolates was quantified, phenotypically characterized, purified. From caracterized after, was evaluated for their nitrogenase activity in vitro. The resultas show diazotrophics bacteria growth in the three forage grasses tested. The ocorrency diazotrophics bacteria be influencied by genotipic plant and seasonal variation. A more density of NSDB of the genus Azospirillum associated in the root grasses were obtained in dry season. The NSDB isolates, show a high potencial for new studies on the genetic caracteristcs and avaliation the inoculo potential to (BNF associated on grasses in semiarid region.

A segment of the apospory-specific genomic region is highly microsyntenic not only between the apomicts Pennisetum squamulatum and buffelgrass, but also with a rice chromosome 11 centromeric-proximal genomic region.

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Gualtieri, Gustavo; Conner, Joann A; Morishige, Daryl T; Moore, L David; Mullet, John E; Ozias-Akins, Peggy

2006-03-01

Bacterial artificial chromosome (BAC) clones from apomicts Pennisetum squamulatum and buffelgrass (Cenchrus ciliaris), isolated with the apospory-specific genomic region (ASGR) marker ugt197, were assembled into contigs that were extended by chromosome walking. Gene-like sequences from contigs were identified by shotgun sequencing and BLAST searches, and used to isolate orthologous rice contigs. Additional gene-like sequences in the apomicts' contigs were identified by bioinformatics using fully sequenced BACs from orthologous rice contigs as templates, as well as by interspecies, whole-contig cross-hybridizations. Hierarchical contig orthology was rapidly assessed by constructing detailed long-range contig molecular maps showing the distribution of gene-like sequences and markers, and searching for microsyntenic patterns of sequence identity and spatial distribution within and across species contigs. We found microsynteny between P. squamulatum and buffelgrass contigs. Importantly, this approach also enabled us to isolate from within the rice (Oryza sativa) genome contig Rice A, which shows the highest microsynteny and is most orthologous to the ugt197-containing C1C buffelgrass contig. Contig Rice A belongs to the rice genome database contig 77 (according to the current September 12, 2003, rice fingerprint contig build) that maps proximal to the chromosome 11 centromere, a feature that interestingly correlates with the mapping of ASGR-linked BACs proximal to the centromere or centromere-like sequences. Thus, relatedness between these two orthologous contigs is supported both by their molecular microstructure and by their centromeric-proximal location. Our discoveries promote the use of a microsynteny-based positional-cloning approach using the rice genome as a template to aid in constructing the ASGR toward the isolation of genes underlying apospory.

Evaluación morfológica del cultivar de buffelgrass “Lucero INTA-PEMAN” en condiciones de sequía

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GRUNBERG, K

2011-04-01

Full Text Available En la búsqueda de nuevos cultivares nacionales mejor adaptados a las restricciones edafo-climáticas presentes en el noroeste argentino, principalmente estrés por sequía y salinidad, un híbrido de buffelgrass (Cenchrus ciliaris L. denominado Lucero INTA-PEMAN fue obtenido mediante cruzamientos controlados en el Instituto de Fitopatología y Fisiología Vegetal (IFFIVE, INTA. El objetivo fue evaluar morfológicamente al cultivar Lucero en comparación a los cultivares Texas-4464, Biloela y Molopo, en Deán Funes (Norte de Córdoba, Argentina a campo bajo condiciones de sequía, en un diseño en bloques completos aleatorizados con tres repeticiones y por dos ciclos de cultivo (2006/2007 y 2007/2008, considerándose como estados ontogénicos planta de un año y rebrote, respectivamente. Se analizaron 13 caracteres morfológicos mediante ANAVA y test DGC (p<0,05. A pesar de que la expresión de la mayoría de los 13 caracteres morfológicos evaluados disminuyó en rebrote, con respecto al primer año de implantación, Lucero INTA-PEMAN fue el menos afectado por la baja disponibilidad de agua y se comportó superior en ambos estados ontogénicos, en caracteres componentes de producción de semillas y fue similar inclusive superior, en caracteres de producción de biomasa a los cultivares Biloela, Molopo y Texas-4464. Lucero INTA-PEMAN se muestra como promisorio y de considerable valor forrajero para las regiones afectadas por sequía, tales como el noroeste argentino.

A Segment of the Apospory-Specific Genomic Region Is Highly Microsyntenic Not Only between the Apomicts Pennisetum squamulatum and Buffelgrass, But Also with a Rice Chromosome 11 Centromeric-Proximal Genomic Region1[W

Science.gov (United States)

Gualtieri, Gustavo; Conner, Joann A.; Morishige, Daryl T.; Moore, L. David; Mullet, John E.; Ozias-Akins, Peggy

2006-01-01

Bacterial artificial chromosome (BAC) clones from apomicts Pennisetum squamulatum and buffelgrass (Cenchrus ciliaris), isolated with the apospory-specific genomic region (ASGR) marker ugt197, were assembled into contigs that were extended by chromosome walking. Gene-like sequences from contigs were identified by shotgun sequencing and BLAST searches, and used to isolate orthologous rice contigs. Additional gene-like sequences in the apomicts' contigs were identified by bioinformatics using fully sequenced BACs from orthologous rice contigs as templates, as well as by interspecies, whole-contig cross-hybridizations. Hierarchical contig orthology was rapidly assessed by constructing detailed long-range contig molecular maps showing the distribution of gene-like sequences and markers, and searching for microsyntenic patterns of sequence identity and spatial distribution within and across species contigs. We found microsynteny between P. squamulatum and buffelgrass contigs. Importantly, this approach also enabled us to isolate from within the rice (Oryza sativa) genome contig Rice A, which shows the highest microsynteny and is most orthologous to the ugt197-containing C1C buffelgrass contig. Contig Rice A belongs to the rice genome database contig 77 (according to the current September 12, 2003, rice fingerprint contig build) that maps proximal to the chromosome 11 centromere, a feature that interestingly correlates with the mapping of ASGR-linked BACs proximal to the centromere or centromere-like sequences. Thus, relatedness between these two orthologous contigs is supported both by their molecular microstructure and by their centromeric-proximal location. Our discoveries promote the use of a microsynteny-based positional-cloning approach using the rice genome as a template to aid in constructing the ASGR toward the isolation of genes underlying apospory. PMID:16415213

WEED CONTROL IN GENETICALLY MODIFIED GLYPHOSATE-TOLERANT SOYBEAN MANEJO DE PLANTAS DANINHAS EM SOJA GENETICAMENTE MODIFICADA TOLERANTE AO GLYPHOSATE

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Júlio Cezar Durigan

2011-04-01

Full Text Available The transgenic production systems, as well as conventional systems, require, in addition to chemical control, the adoption of other weed management strategies. This study was developed to evaluate the weed chemical control in glyphosate tolerant soybean, associated to cover crops cultivated in the autumn/winter. The experiment was carried out under field conditions at the FCAV/Unesp, Jaboticabal, São Paulo State, Brazil. A randomized split-plot block design was used, with four replications. St. Lucia Grass (Brachiaria brizantha ‘Marandu’, forage millet (Pennisetum americanum ‘BN2’, and a treatment with spontaneous growth vegetation were evaluated for plots, and, for subplots, the herbicides glyphosate, chlorimuron - ethyl plus lactofen, and fluazifop-p-butyl, in a sequential spraying, and two controls without any application. Grass cover contributed to the chemical control, suppressing weeds, and the single application of 720 g a.e. ha-1 of glyphosate, independently of the cover crop cultivated in the autumn/winter, was sufficient for adequately controlling Acanthospermum hispidum, Alternanthera tenella, Amaranthus sp., Bidens pilosa, Xanthium strumarium, Cenchrus echinatus, Digitaria sp., and Eleusine indica, with results similar to the treatment (chlorimuron-ethyl + lactofen + fluazifop-p-buthyl. When compared to the weeded control, the herbicides did not affect plants height, dry matter of the aerial parts, mass of 100 grains, and grain yield. Soybean plants grown over St. Lucia Grass and forage millet presented a higher height, however, no other feature was influenced by the cover crop.

KEY-WORDS: Brachiaria brizantha; Pennisetum americanum; no-tillage; Roundup Ready; spontaneous vegetation.

Os sistemas de produção transgênicos, assim como os

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

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F.T. Carvalho

2010-01-01

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

Otimização da aplicação de Fluazifop-P-Butil em pós-emergência na cultura de soja (Glycine max Optimizing Fluazifop-P-Butyl application on postemergence soybeans (Glycine max

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P.R.F. Lima

2001-04-01

Full Text Available O objetivo deste trabalho foi avaliar a possibilidade de redução da dosagem e do volume de calda em função do horário de aplicação do herbicida fluazifop-p-butil em pós-emergência na cultura de soja, mantendo-se o controle das plantas daninhas e a seletividade para a cultura. O experimento foi conduzido na área experimental da Fazenda de Ensino e Pesquisa da FCAV/UNESP - Jaboticabal, no ano agrícola 1998/99, na cultura de soja, cultivar FT 2009. O delineamento experimental utilizado foi o de blocos ao acaso com 24 tratamentos, sendo 20 dispostos no esquema fatorial 2 x 2 x 5 e quatro testemunhas. Os fatores testados foram: volume de calda (100 e 200 L de calda/ha; dosagens reduzidas -75,2 e 112,8 g de fluazifop-p-butil/ha (respectivamente a 40 e 60% da dosagem recomendada; e horário de aplicação (5, 9, 13, 17 e 21 horas. As testemunhas foram aplicadas com a dosagem recomendada (188,0 g do fluazifop-p-butil/ha e com os volumes de 100 e 200 L de calda/ha, no mato (sem controle das plantas daninhas e "no limpo" (plantas daninhas controladas com enxada manual. As principais espécies de plantas daninhas que emergiram na área experimental foram capim-carrapicho (Cenchrus echinatus, que compunha 60% da comunidade infestante; capim-colchão (Digitaria horizontalis, 10%; e capim-pé-de-galinha (Eleusine indica, 30%. Todas as aplicações do herbicida fluazifop-p-butil, nos horários até as 9 horas e a partir das 17 horas, controlaram eficientemente as três espécies de plantas daninhas e foram seletivas para a cultura de soja. Portanto, o uso do herbicida fluazifop-p-butil pode ser otimizado por meio de reduções na dosagem e no volume de calda em aplicações durante os horários com condições ambientais favoráveis à pulverização.The objective of this study was to evaluate the possibility of reducing spray concentration and volume of Fluazifop-p-butyl applications on postemergence soybeans, while maintaining weed control and

Plantas infestantes em lavouras de milho safrinha, sob diferentes manejos, no Médio Paranapanema Weed in second corn crops submitted to different systems in the Médio Paranapanema Region

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A.P. Duarte

2007-01-01

Full Text Available Um levantamento de plantas daninhas foi realizado em 20 lavouras de milho safrinha em 1997 e 40 em 1998 e 1999, depois da soja, na região do Médio Paranapanema-SP. O levantamento abrangeu os municípios de Assis, Campos Novos, Cândido Mota, Cruzália, Florínea, Maracaí, Palmital, Pedrinhas Paulista e Platina. No estádio de enchimento de grãos, as lavouras foram percorridas em ziguezague, a partir de quatro pontos de entrada, de maneira a representar a área total. As lavouras foram subdivididas de acordo com as condições de manejo das culturas: semeadura direta, semeadura convencional em solo preparado com grade e semeadura de milho safrinha na palha de soja cultivada no sistema convencional. Em cada lavoura foram cadastrados o nível de infestação e as espécies daninhas. Foram coletadas informações quanto ao manejo das plantas daninhas adotado nas lavouras, assim como sobre os herbicidas empregados. As espécies de plantas daninhas mais importantes foram Cenchrus echinatus, Bidens pilosa, Euphorbia heterophylla, Raphanus sativus, Digitaria horizontalis, Commelina benghalensis, Amaranthus sp., Achyrocline satureioides, Sinapis arvensis, Sida sp., Glycine max, Avena strigosa, Eleusina indica e Sorghum halepense. Houve acentuado aumento na infestação da espécie C. echinatus nas lavouras, a qual passou a constituir-se na principal espécie infestante. R. sativus também se tornou importante e apresentou grande incremento de 1997 a 1999. Na semeadura convencional houve predomínio de alta infestação, evidenciando desempenho inferior desse sistema em relação aos demais no controle de plantas daninhas. O controle químico mais utilizado foi a mistura atrazine + óleo vegetal + 2,4-D, seguido por atrazine + óleo e atrazine isolado. De modo geral, não se efetuou o controle das plantas daninhas em 22% das lavouras, as quais apresentaram as maiores porcentagens de infestação. O nível de infestação em função do tipo de

Avaliação de herbicidas no controle de plantas daninhas na cultura da soja Evaluation of herbicides in the control of weeds in the soybean crop

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A.C. De Barros

1992-01-01

Full Text Available Foi conduzido em Serranópolis, GO, um ensaio objetivando avaliar a eficiência e a seletividade de herbicidas no controle de plantas daninhas na cultura da soja (Glycine max (L. Merril, utilizando-se os seguintes tratamentos: A 100 g/ha de imazethapyr (ácido 2-[4,5-dihidro-4-metil-4(1-metiletil-5-oxo-1H-imidazol-2-ilo]-5-etil-3-piridinacarboxilico + surfactante, a 0,25% v/v; B tratamento A e 15 dias após, 230 g/ha de sethoxydim (2-1-etoximino-butil-5-2(etiltio-propil-3-hidroxi-2-ciclohexeno-1-ona + óleo mineral, a 0,25% v/v; C 230 g/ha de sethoxydim + óleo mineral, a 0,25% v/v; D 480 + 200 + 230 g/ha de bentazon (3-isopropil-2,1,3-benzotiadiazinona-(4-2,2-dióxido + fomesafen (5-2-cloro-4-(trifluorometil-fenoxiN-metilsulfonil-2-nitrobenzamida + sethoxydim + óleo mineral, 0,25% v/v; E 150 g/ha de imazaquim (2-[4,5-dihidro-4-metil-4-(1-metiletil-5-oxo-1H-imidazol-2-ilo]-3-quinolinacarboxílico pré-e e 230 g/ha de sethoxydim + óleo mineral, 0,25% v/v; F 250 g/ha de fomesafen + 187 g/ha de fluazipop-p-butil (butil-(R-2-(4-(5-trifluorometil-2-piridiloxi-fenoxi-propionato + surfactante a 0,2% v/v; G 120 g/ha de imazethapyr + surfactante a 0,2% v/v; H testemunha capinada; I testemunha não capinada. O delineamento experimental foi de blocos ao acaso, com quatro repetições. O capim-custódio (Pennisetum setosum (Swartz L. Rich foi eficientemente controlado por todos os tratamentos químicos, enquanto a falsa-serralha (Emilia sonchifolia DC. foi somente pelo tratamento D. O capim-carrapicho (Cenchrus echinatus L. por C, D, E e F. O joá-de-capote (Nicandra physaloides (L. Pers. por D.F. e G. Ocorreram injúrias iniciais às plantas de soja, nos tratamentos D, E. e F. As alturas de plantas e de inserção da primeira vagem, além do rendimento de grãos, não foram influenciados significativamente pelos herbicidas.An experiment was carried out in Serranópolis, State of Goiás, Brazil, aiming to evaluate herbicides efficiency in weeds control

Misturas em tanque com glyphosate para o controle de trapoeraba, erva-de-touro e capim-carrapicho em soja RR®

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Cleber Daniel de Goes Maciel

2011-02-01

Full Text Available O uso de misturas de glyphosate, em tanque, para manejo de espécies de plantas daninhas de difícil controle tem sido prática comum entre os agricultores brasileiros. Desta forma, este trabalho teve como objetivo avaliar a eficácia e seletividade de misturas, em tanque, de herbicidas com glyphosate para o controle de trapoeraba (Commelina benghalensis L., erva-de-touro (Tridax procumbens L. e capim-carrapicho (Cenchrus echinatus L. na cultura da soja RR®. O experimento foi conduzido em Maracaí, São Paulo, no período de novembro de 2006 a março de 2007, utilizando-se o cultivar CD-214RR® e delineamento experimental de blocos ao acaso, com 21 tratamentos e quatro repetições. Os tratamentos foram constituídos da aplicação de: glyphosate (180; 360; 540 e 720 g ha-1; glyphosate em sequencial (180/360; 360/360 e 540/360 g ha-1; glyphosate + chlorimuron-ethyl 360+10; 540+10; 360+5/ 360+5 g ha-1; glyphosate + lactofen (360+120; 540+120; 360+60/ 360+60 g ha-1; glyphosate + cloransulam-methyl (360+30; 540+30; 360+16,9/ 360+12,9 g ha-1; glyphosate + carfentrazone (360+4 g ha-1; glyphosate + imazethapyr (360+50 g ha-1; glyphosate + imazethapyr (177,8+30 g ha-1 e testemunhas capinada e sem capina. Apesar da similaridade de produtividade de grãos entre os tratamentos com glyphosate isolado e sequencial, nas doses 540, 720 e 540/ 360 g ha-1, as misturas em tanque com chlorimuron-ethyl, cloransulam-methyl, lactofen e imazethapyr favoreceram o controle de espécies de plantas daninhas tolerantes ao glyphosate como C. benghalensis e T. procumbens.

Introduced and invasive species in novel rangeland ecosystems: friends or foes?

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Belnap, Jayne; Ludwig, John A.; Wilcox, Bradford P.; Betancourt, Julio L.; Dean, W. Richard J.; Hoffmann, Benjamin D.; Milton, Sue J.

2012-01-01

Globally, new combinations of introduced and native plant and animal species have changed rangelands into novel ecosystems. Whereas many rangeland stakeholders (people who use or have an interest in rangelands) view intentional species introductions to improve forage and control erosion as beneficial, others focus on unintended costs, such as increased fire risk, loss of rangeland biodiversity, and threats to conservation efforts, specifically in nature reserves and parks. These conflicting views challenge all rangeland stakeholders, especially those making decisions on how best to manage novel ecosystems. To formulate a conceptual framework for decision making, we examined a wide range of novel ecosystems, created by intentional and unintentional introductions of nonnative species and land-use–facilitated spread of native ones. This framework simply divides decision making into two types: 1) straightforward–certain, and 2) complex–uncertain. We argue that management decisions to retain novel ecosystems are certain when goods and services provided by the system far outweigh the costs of restoration, for example in the case of intensively managed Cenchrus pastures. Decisions to return novel ecosystems to natural systems are also certain when the value of the system is low and restoration is easy and inexpensive as in the case of biocontrol of Opuntia infestations. In contrast, decisions whether to retain or restore novel ecosystems become complex and uncertain in cases where benefits are low and costs of control are high as, for example, in the case of stopping the expansion of Prosopis and Juniperus into semiarid rangelands. Decisions to retain or restore novel ecosystems are also complex and uncertain when, for example, nonnative Eucalyptus trees expand along natural streams, negatively affecting biodiversity, but also providing timber and honey. When decision making is complex and uncertain, we suggest that rangeland managers utilize cost–benefit analyses

Simulating long-term effectiveness and efficiency of management scenarios for an invasive grass

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Jarnevich, Catherine S.; Holcombe, Tracy R.; Cullinane Thomas, Catherine; Frid, Leonardo; Olsson, Aaryn D.

2015-01-01

Resource managers are often faced with trade-offs in allocating limited resources to manage plant invasions. These decisions must often be made with uncertainty about the location of infestations, their rate of spread and effectiveness of management actions. Landscape level simulation tools such as state-and-transition simulation models (STSMs) can be used to evaluate the potential long term consequences of alternative management strategies and help identify those strategies that make efficient use of resources. We analyzed alternative management scenarios for African buffelgrass (Pennisetum ciliare syn. Cenchrus ciliaris) at Ironwood Forest National Monument, Arizona using a spatially explicit STSM implemented in the Tool for Exploratory Landscape Scenario Analyses (TELSA). Buffelgrass is an invasive grass that is spreading rapidly in the Sonoran Desert, affecting multiple habitats and jurisdictions. This invasion is creating a novel fire risk and transforming natural ecosystems. The model used in this application incorporates buffelgrass dispersal and establishment and management actions and effectiveness including inventory, treatment and post-treatment maintenance. We simulated 11 alternative scenarios developed in consultation with buffelgrass managers and other stakeholders. The scenarios vary according to the total budget allocated for management and the allocation of that budget between different kinds of management actions. Scenario results suggest that to achieve an actual reduction and stabilization of buffelgrass populations, management unconstrained by fiscal restrictions and across all jurisdictions and private lands is required; without broad and aggressive management, buffelgrass populations are expected to increase over time. However, results also suggest that large upfront investments can achieve control results that require relatively minimal spending in the future. Investing the necessary funds upfront to control the invasion results in the most

Simulating long-term effectiveness and efficiency of management scenarios for an invasive grass

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Catherine S. Jarnevich

2015-05-01

Full Text Available Resource managers are often faced with trade-offs in allocating limited resources to manage plant invasions. These decisions must often be made with uncertainty about the location of infestations, their rate of spread and effectiveness of management actions. Landscape level simulation tools such as state-and-transition simulation models (STSMs can be used to evaluate the potential long term consequences of alternative management strategies and help identify those strategies that make efficient use of resources. We analyzed alternative management scenarios for African buffelgrass (Pennisetum ciliare syn. Cenchrus ciliaris at Ironwood Forest National Monument, Arizona using a spatially explicit STSM implemented in the Tool for Exploratory Landscape Scenario Analyses (TELSA. Buffelgrass is an invasive grass that is spreading rapidly in the Sonoran Desert, affecting multiple habitats and jurisdictions. This invasion is creating a novel fire risk and transforming natural ecosystems. The model used in this application incorporates buffelgrass dispersal and establishment and management actions and effectiveness including inventory, treatment and post-treatment maintenance. We simulated 11 alternative scenarios developed in consultation with buffelgrass managers and other stakeholders. The scenarios vary according to the total budget allocated for management and the allocation of that budget between different kinds of management actions. Scenario results suggest that to achieve an actual reduction and stabilization of buffelgrass populations, management unconstrained by fiscal restrictions and across all jurisdictions and private lands is required; without broad and aggressive management, buffelgrass populations are expected to increase over time. However, results also suggest that large upfront investments can achieve control results that require relatively minimal spending in the future. Investing the necessary funds upfront to control the invasion

Allelopathic effects of the invasive Prosopis juliflora (Sw. DC. on selected native plant species in Middle Awash, Southern Afar Rift of Ethiopia

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Samuel Getachew

2012-12-01

Full Text Available The allelopathic effects of the invasive Prosopis juliflora (Sw. DC. was studied on seed germination and seedling growth of Acacia nilotica(L. Willd. ex Del., Acacia tortilis (Forssk. Hayne, Cenchrus ciliaris L. and Enteropogon rupestris (J.A. Schmidt A. Chev. Vegetation sampling in different habitat types in the area was made to identify the target plant species. Comparison of canopy characteristics among P. juliflora, A. nilotica and A. tortilis was also made to observe differences if any in canopy closure. P. juliflora was recorded in all habitat types in highest density and observed affecting the plant diversity there in. Its growth characteristics and dense thicket formation restrict light to the ground flora and hence diminishes plant diversity. Leaf, bark and root aqueous extract of P. juliflora at 0, 0.5, 0.8, 1, 2 and 6% wereprepared and their effect studied on germination percentage and seedling growth of the study plant species. Germination of A. nilotica and A. tortilis was not affected by all aqueous extracts of different organ parts of P. juliflora while leaf and root extracts at higher concentrations inhibited germination of C. ciliaris and E. rupestris. Shoot and root growth of the study species were inhibited by leaf and root at higher concentrations. Seed germination of all species except A. nilotica was inhibited by soil amended with decaying plant parts and under canopy soil. The effect is species specific and annuals (grasses and herbs were affected more than perennials. Leaf seems to contain greater number/amount of inhibitors than does root and bark. Bark seems to contain the least. Heavy accumulation of toxic substances at under canopy soil of P. juliflora may be one of the reasons for its invasiveness and low plant diversity.

Relación carbono-nitrógeno en suelos de sistemas silvopastoriles del Chaco paraguayo

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Cynthia Gamarra

2018-03-01

Full Text Available El sistema silvopastoril permite que la producción ganadera sea más sustentable, porque la interacción entre sus componentes aporta beneficios al suelo, a la pastura, al ganado y a los árboles; además de, un aumento en la productividad y la diversificación de la producción. Para conocer las características de dichos sistemas, se llevó a cabo un estudio en propiedades privadas ubicadas en el Chaco Paraguayo, donde se instalaron ocho parcelas permanentes de 1 ha cada una, en las que se midieron todos los individuos de Prosopis spp. (algarrobo, se identificaron y extrajeron muestras de pastura de subparcelas situadas bajo la copa de los árboles y fuera de ella para comparar su biomasa; también se obtuvieron muestras de suelo en las mismas condiciones, a dos profundidades: de 0 a 10 cm y de 10 a 30 cm, con el propósito de comparar el contenido de materia orgánica y la Relación Carbono/Nitrógeno (C/N. El componente arbóreo estaba integrado por Prosopis alba (algarrobo blanco y Prosopis nigra (algarrobo negro asociados a pastura cultivada compuesta en forma mayoritaria por Panicum maximum cv Gatton panic (Gatton panic, Digitaria decumbens (pasto pangola y Cenchrus ciliaris (pasto buffel. La presencia de los algarrobos influyó sobre la biomasa de la pastura, pues sus registros fueron mayores bajo las copas que fuera de estas. La materia orgánica en el suelo no presentó diferencias significativas entre condición de sol y de sombra, pero sí al variar la profundidad; en cambio, la Relación C/N no varió en ninguna de las condiciones.

Efeito da suplementação com feno de Leucena (Leucaena leucocephala (Lam de Wit durante a estação seca sobre o desenvolvimento ponderal de ovinos Effect of supplementation with Leucaena leucocephala hay during the dry season on the ponderal development sheep

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Antônio Alves de Souza

1999-01-01

Full Text Available O objetivo deste experimento foi estudar o desempenho de borregos suplementados com dois níveis de feno de leucena (Leucaena leucocephala (Lam de Wit, durante a estação seca, em comparação com animais mantidos em pastagem exclusiva de capim-buffel (Cenchrus ciliaris, L ou em pastagem consorciada de capim-buffel com guandu (Cajanus cajan. Durante a estação das águas, foi determinado ainda o desempenho dos animais que foram mantidos em pastagem comum de capim-buffel, sem suplementação. Os seguintes tratamentos foram testados durante a estação seca: A - pasto de capim-buffel; B - pasto de capim-buffel consorciado com guandu; C - pasto de capim-buffel suplementado com feno de leucena (250 g/animal•d; e D - pasto de capim-buffel suplementado com feno de leucena (500 g/animal•d. Durante a estação seca, somente os borregos suplementados com o nível mais alto de feno de leucena (tratamento D apresentaram ganho diário de peso mais elevado que os animais mantidos em dieta exclusiva de pasto (tratamentos A e B. Na estação das águas, os animais que apresentaram melhor desempenho durante a estação seca passaram a apresentar ganho diário de peso inferior em relação aos dos demais tratamentos. Quando as duas estações foram consideradas em conjunto, a vantagem com a suplementação desapareceu e não houve diferenças entre tratamentos. O uso de feno de leucena para suplementação de borregos mantidos a pasto, durante a estação seca, é eficiente, desde que os animais estejam terminados e sejam abatidos ao final da estação.

Avaliação de herbicidas aplicados em pós-emergência sobre e sob a palha em cana crua e o destino ambiental Evaluation of herbicides applied in post-emergence over and under straw in no-burn sugarcane and their environmental fate

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L.L. Foloni

2011-06-01

Full Text Available O objetivo deste trabalho foi avaliar a eficiência de vários herbicidas isolados ou associados, aplicados em pós-emergência, na cultura da cana-soca, colhida mecanicamente no sistema cana crua, procurando evidenciar diferenças no seu desempenho quando aplicados sobre ou sob a palha, bem como, ainda dentro do conceito de sustentabilidade e avaliação de risco ambiental, quantificar os comportamentos nos quais esses produtos apresentam maior risco. O experimento foi conduzido no município de Bariri-SP, em áreas da Usina Della Colletta, Fazenda Santo Antonio, em área de cana-soca (cultivar RB 72 754 colhida mecanicamente. Foi utilizada a cana-soca de quarto corte, plantada no espaçamento de 1,40 m, em solo Argiloso Vermelho-Amarelo com 5% de declive. Empregou-se o delineamento experimental de blocos ao acaso com 14 tratamentos (trifloxysulfuron-sodium+ametrina 720 e 960; mesotrione 182 e 292,6; mesotrione+ametrina 292,6+1.500; mesotrione+trifloxysulfuron-sodium 182,8+720; metribuzin 2.680; trifloxysulfuron-sodium+ametrina + hexazinone+diuron 720+900; amicarbazone 45; hexazinone+diuron 1.320; trifloxysulfuron-sodium+sulfentrazone 720+700 (todos em gramas de ingrediente ativo; testemunha; testemunha capinada e quatro repetições, para cada tipo de aplicação (sobre e sob a palha disposta lado a lado. As avaliações realizadas foram: fitotoxicidade aparente, altura, estande, eficiência no controle da Digitaria horizontalis, Cenchrus echinatus, Emilia fosbergii e Sida cordifolia, números de internódios e o primeiro internódio. O modelo matemático foi o nível I de fugacidade, utilizando os compartimentos ar, água, solo, sedimento, biota, raiz, caule e folha. Os resultados mostraram que os herbicidas trifloxysulfuron + diuron, mesotrione, metribuzin, ametrina, hexazinone + diuron, amicarbazone e sulfentrazone isolados ou associados, aplicados em pós-emergência, em área total da cultura da cana-de-açúcar, foram altamente

Herbicidas de aplicação em pós-emergência em amendoim: I: controle de plantas daninhas e persistência no solo Post emergence herbicides in peanuts: I: weed control and persistence in the soil

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Luciano Souza Paes Cruz

1991-01-01

Full Text Available No ano agrícola 1987/88, foi realizado um experimento de campo na Estação Experimental de Ribeirão Preto, do Instituto Agronômico, em latossolo roxo, textura argilosa, com a finalidade de pesquisar a ação dos herbicidas aplicados em pós-emergência no controle de plantas daninhas e sua persistência em solo, na cultura de amendoim (Arachis hypogaea L. O experimento foi em parcelas subdivididas com as parcelas distribuídas em blocos ao acaso com quatro repetições. Nas parcelas, estudaram-se os tratamentos referentes à presença e à ausência de inoculação, sendo o inoculante preparado com a mistura de estirpes de Bradyrhizobium sp. (SMS-319, SMS-400 e SMS-561; nas subparcelas, os herbicidas fomesafen (250g/ha, lactofen (192g/ha, fluazifop-p-butil (187g/ha, haioxifop-metil (240g/ha e a mistura de fomesafen com fluazifop-p-butil (250 + 187g/ha, além de uma testemunha sem herbicida. Nas entrelinhas das subparcelas, tomaram-se ao acaso cinco pontos paraformar uma amostrado solo composta para análise de persistência dos produtos. As principais plantas daninhas presentes no experimento foram as gramíneas Cenchrus echinatus L. e Eleusine indica (L. Gaerth, e as dicotiledôneas Alternanthera fícoidea(L. R. Br. e Sidaspp. Aos 20 dias da aplicação dos herbicidas, as gramíneas foram 100% controladas pelos graminicidas fluazifop-p-butil e haioxifop-metil. Fomesafen e lactofen controlaram eficientemente A. fícoidea e, regularmente, Sida spp. A mistura de fomesafen com fluazifop-p-butil não apresentou vantagens em relação aos herbicidas isolados. Os resultados obtidos mostraram que não houve influenciada inoculação no controle de plantas daninhas e que os herbicidas não foram tóxicos às plantas de amendoim. Os herbicidas fluazifop-p-butil e haioxifop-metil, aos 28 dias, não mais causavam fitotoxicidade na planta-teste, mostrando uma persistência no solo inferior a esse período. Aos 28 dias, no tratamento não inoculado

Liberación ruminal de cuatro fuentes inorgánicas de magnesio por medio de la técnica in situ en ganado holstein en trópico alto

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Wilmer Alfonso Cuervo Vivas

2017-06-01

Full Text Available El Magnesio, abundante en praderas pastoreadas por bovinos de leche, actúa como un cofactor en reacciones enzimáticas vitales para las principales vías metabólicas y presenta desaparición ruminal elevada (87% aunque se desconoce su liberación en fuentes inorgánicas. Con el objetivo de evaluar su solubilización ruminal se incubaron cuatro fuentes inorgánicas (óxido de Mg (MgO, sulfato de Mg (MgSO4, cloruro de Mg (MgCl2 y carbonato de Mg (MgCO3 determinando su desaparición de la materia seca (DMS en 3 vacas Holstein (vacías, no lactantes canuladas al rumen (620 ± 14 kg y 7 años en el municipio de Santa Elena, Antioquia, Colombia (2538 msnm; bH – MB; 16ºc consumiendo kikuyo (Cenchrus clandestinus (Hoechst Ex Chiov Morrone (Chemisquy et al 2010. Por triplicado se incubaron 0,5 g de cada fuente en bolsas de nailon con dos tamaños de poro (25 y 50μm, en el rumen de las vacas para evaluar DMS en tres tiempos (0, 12 y 24h. Se utilizó un diseño en bloques completos al azar con un arreglo factorial 2x3x4 (2 tamaños de poro, 3 tiempos de incubación y 4 fuentes minerales y prueba de Tukey para significancia estadística de las diferencias. La incubación ruminal debe realizarse con tamaño de poro no superior a 50um, siendo MgCl2 y MgSO4 mas solubles en rumen, mientras que óxidos y carbonatos presentan solubilidad baja o nula dentro de las primeras 24 horas, lo cual puede dar luces para su utilización como suplemento mineral dentro de la dieta solida o agua de bebida del ganado lechero.

Influence of tree species on the herbaceous understory and soil chemical characteristics in a silvopastoral system in semi-arid northeastern Brazil

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R. S. C. Menezes

1999-12-01

Full Text Available Studies from some semi-arid regions of the world have shown the beneficial effect of trees in silvopastoral systems, by promoting the formation of resource islands and increasing the sustainability of the system. No data are available in this respect for tree species of common occurrence in semi-arid Northeastern Brazil. In the present study, conducted in the summer of 1996, three tree species (Zyziphus joazeiro, Spondias tuberosa and Prosopis juliflora: found within Cenchrus ciliaris pastures were selected to evaluate differences on herbaceous understory and soil chemical characteristics between samples taken under the tree canopy and in open grass areas. Transects extending from the tree trunk to open grass areas were established, and soil (0-15 cm and herbaceous understory (standing live biomass in 1 m² plots samples were taken at 0, 25, 50, 100, 150 and 200% of the average canopy radius (average radius was 6.6 ± 0.5, 4.5 ± 0.5, and 5.3 ± 0.8 m for Z. joazeiro, P. juliflora, and S. tuberosa , respectively. Higher levels of soil C, N, P, Ca, Mg, K, and Na were found under the canopies of Z. joazeiro and P. juliflora: trees, as compared to open grass areas. Only soil Mg organic P were higher under the canopies of S. tuberosa trees, as compared to open grass areas. Herbaceous understory biomass was significantly lower under the canopy of S. tuberosa and P. juliflora trees (107 and 96 g m-2, respectively relatively to open grass areas (145 and 194 g m-2. No herbaceous biomass differences were found between Z. joazeiro canopies and open grass areas (107 and 87 g m-2, respectively. Among the three tree species studied, Z. joazeiro was the one that presented the greatest potential for use in a silvopastoral system at the study site, since it had a larger nutrient stock in the soil without negatively affecting herbaceous understory biomass, relatively to open grass areas.

Changes in organic matter (C, N and P) of soils under subsistence agriculture

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Fraga, Vania da Silva

2002-10-01

Productivities under low input or subsistence agriculture are strongly dependent on nutrient supply from soil organic matter mineralization (SOM). Few results are available and they indicate declines in soil fertility under this agricultural system, particularly in SOM levels. In an attempt to understand the nature and extent of these declines we selected ten sites having cultivated areas adjacent with areas under native vegetation at the same slope position, in the states of Pernambuco and Paraiba. Based on the management history, in situ observations and 137 Cs concentrations to evaluate soil erosion, the areas were divided in four groups having different levels of soil use intensity: Undisturbed Dry Forest (UDF), Disturbed Dry Forest (DDF), Preserved-Cultivated (PC) and Degraded-Cultivated (DC). In the first part of this work we quantified total organic C, N and P, in addition to 137 Cs concentrations, under the assumption that changes in organic nutrient contents among land use groups would be greater than the within group variability, thus enabling inferences at a regional scale. Concentrations of C and N in DC were 50% smaller (P -3 ) (C-lf); C-CO 2 produced during three days of incubation (C-min3d); C oxidized with 333 mM (C-ox 333) and 16,5 mM (C-ox16) KMnO 4 . The only fraction that did not correlate with total C was C-fl. Average proportions of total C extracted by C-mins3d, C-ox 16 were 1.5%, 24% and 7.2 %, respectively. In the second phase, the whole sample set (n=160) was analyzed for C-ox16. This C fraction decreased from 1.65 g kg -1 under UDF to 0.70 in DC (P -1 , in a pot experiment. Total C correlated significantly with N mineralized in 60 d (N-min60d) (r=0.79***) while N-min60 and P-Mehlich-1 explained 80% of the variation in dry matter production by buffel grass (Cenchrus ciliaris). Low P availability, C and N losses, limited water availability and sometimes-inappropriate land management techniques, are considered strong limiting conditions for

Medicinal flora of the Cholistan desert: a review

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Hmeed, M.; Ashraf, M.; Nawaz, T.; Naz, N.; Ahmad, M.S.A.; Al-Quriany, F.; Younis, A.

2011-01-01

The Cholistan desert can be divided into two distinct regions on the basis of topography, soil type and texture, and vegetation structure: the northern Lesser Cholistan and southern Greater Cholistan. The desert is characterized by large saline compacted areas with alluvial clay, sandy ridges and dunes, and semi-stabilized to frequently shifting dunes. The climate is subtropical, harsh, hot and arid, and influenced by seasonal monsoons. Vegetation cover on the sand dunes is comprised by a few tussock-forming grasses including Cenchrus ciliaris, Panicum turgidum and Lasiurus scindicus, along with perennial shrubs Calligonum polygonoides, Leptadenia pyrotechnica and Aerva javanica. Interdunal flats are dominated by grasses, mainly Cymbopogon jwarancusa, Sporobolus ioclados, Panicum antidotale, and Ochthochloa compressa, and tall shrubs Calligonum polygonoides and Capparis decidua. Vegetation of saline patches is specific, dominated by halophytes mainly belonging to family Chenopodiaceae (Amaranthaceae). Many plants of the Cholistan desert, including Neurada procumbens, Aerva javanica, Capparis decidua, Cleome brachycarpa, Dipterygium glaucum, Gisekia pharnacioides, Suaeda fruticosa, Achyranthes aspera, Aerva javanica, Alhagi maurorum, Calotropis procera, Capparis decidua, Zaleya pentandra, Mollugo cerviana, Ziziphus mauritiana, Boerhavia procumbens, Cressa cretica and Crotalaria burhia, are frequently used by the local inhabitants to cure chronic and acute diseases. A variety of medicinally important chemical compounds have been extracted and identified from the plants of the Cholistan desert, including terpenes and triterpenoids, sterols and steroids, phenolics, flavonoids, gums and resins, quinones, anthocyanidines, saponins, antioxidants and fatty acids. Habitat degradation, intensive agricultural practices and over exploitation of resources pose a serious threat to the diversity of ethno botanically important plant species. Allopathic medicines are generally

Métodos de establecimiento de pasturas en zonas áridas de México utilizando semillas crudas o cariópsides

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Adrián Raymundo Quero-Carrillo

2016-01-01

Full Text Available En 2 sitios del Desierto Chihuahuense, México, se evaluó el establecimiento en secano de las gramíneas nativas Banderita (Bouteloua curtipendula y Navajita (B. gracilis y las introducidas Buffel (Cenchrus ciliaris y Rhodes (Chloris gayana, utilizando cariópsides y/o semillas crudas (semilla limpia con brácteas y aristas y cuatro métodos de tapado. Los sitios de siembra fueron Atotonilco El Grande, Hidalgo y Salinas Hidalgo, San Luis Potosí. Las siembras se hicieron a voleo a razón de 1,000 cariópsides y/o semillas crudas viables/m2. Los métodos de tapado fueron: paso de rastra con ramas; rodillo; rastra con ramas + rodillo; y sin tapado (testigo. Las variables de respuesta incluyeron número de plantas emergidas y de plantas establecidas, diámetro de corona, altura de planta y número de tallos por planta. Se utilizó un diseño completamente al azar con arreglo factorial 2 x 2 x 4 con 3 repeticiones. No se observaron diferencias entre sitios y se establecieron, en promedio, 2 plantas/m2. Con las especies nativas (Banderita y Navajita se obtuvo mayor cantidad de plantas emergidas y establecidas cuando la siembra se hizo con semillas crudas, mientras que en introducidas no se encontró diferencia entre siembra con semilla cruda y siembra con cariópsides. Cuando se utilizó el método de tapado y apisonado del suelo se observaron mayor diámetro de corona y altura de planta. El mayor número de plantas establecidas se obtuvo en pasturas de Navajita y Rhodes. En las especies nativas la eliminación de brácteas accesorias en las semillas no se tradujo en mejor establecimiento, mientras que en las gramíneas introducidas esta práctica sí mejoró el establecimiento. En ambos grupos de especies el apisonado mejoró el establecimiento.Palabras clave: Densidad de siembra, gramíneas introducidas, gramíneas nativas, suelo apisonado, tapado de semilla.DOI: 10.17138/TGFT(429-37  

A influência da cobertura morta sobre características físicas e químicas de frutos da pinha (Annona squamosa L. The influence of mulching in relation to physical and chemical characteristics of the sugar apple (Annona squamosa L.

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José Carlson Gusmão da Silva

2007-08-01

Full Text Available De forma geral a aplicação de resíduos vegetais ao solo tem efeitos benéficos sobre os nutrientes do solo, sob as suas condições físicas, sob a atividade biológica e sobre a performance das culturas. O objetivo principal deste trabalho foi avaliar, durante um ciclo produtivo, o efeito da cobertura de bagaço de cana, casca de café e palha de Buffel (Cenchrus ciliaris, L., quanto ao seu efeito sobre características físicas e químicas do fruto da pinheira (Annona squamosa L.. O delineamento experimental foi o inteiramente casualizado, constando de cinco repetições, contendo duas plantas por parcela. Foram analisados: massa do fruto, massa da casca, massa das sementes e o número de sementes por fruto, o teor de sólidos solúveis e o pH da polpa. De modo geral, a presença da cobertura morta proporcionou incremento de massa aos frutos, o que promove aumento de receita, uma vez que, quanto maior for o fruto, melhor será seu preço. Não ocorreu aumento do pH da polpa, e o tratamento com casca de café proporcionou o maior teor de sólidos solúveis totais. Quanto às demais características, não foram encontradas diferenças.The application of vegetal wastes to soil have a beneficial effects on soil nutrient, physical conditions, biological activities and on the culture performance, the main objective of this study was to evaluate three kinds of vegetable byproducts: sugar cane bagasse, coffee chaff, and Buffel straw, regarding to the effect on the physical and chemical characteristics of custard apple (Annona squamosa L..The experimental design used completely randomid plots with five repplications, and two plants per plot. The total fruit mass, the peel mass, the seed mass per fruit were evaluated. The pulp level of soluble solids was measured, as well as its pH. The presence of this mulching provided an increase in the fruit mass, thereby, increasing the commercial profit, as larger the fruit is, the greater the value per weight

A revision of dragon millipedes I: genus Desmoxytes Chamberlin, 1923, with the description of eight new species (Diplopoda, Polydesmida, Paradoxosomatidae

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Ruttapon Srisonchai

2018-05-01

Full Text Available The dragon millipede genus Desmoxytes s.l. is split into five genera, based on morphological characters and preliminary molecular phylogenetic analyses. The present article includes a review of Desmoxytes s.s., while future articles will deal with Hylomus Cook and Loomis, 1924 and three new genera which preliminarily are referred to as the ‘acantherpestes’, ‘gigas’, and ‘spiny’ groups. Diagnostic morphological characters of each group are discussed. Hylomus is resurrected as a valid genus and the following 33 species are assigned to it: H. asper (Attems, 1937, comb. n., H. cattienensis (Nguyen, Golovatch & Anichkin, 2005, comb. n., H. cervarius (Attems, 1953, comb. n., H. cornutus (Zhang & Li, 1982, comb. n., H. draco Cook & Loomis, 1924, stat. rev., H. enghoffi (Nguyen, Golovatch & Anichkin, 2005, comb. n., H. eupterygotus (Golovatch, Li, Liu & Geoffroy, 2012, comb. n., H. getuhensis (Liu, Golovatch & Tian, 2014, comb. n., H. grandis (Golovatch, VandenSpiegel & Semenyuk, 2016, comb. n., H. hostilis (Golovatch & Enghoff, 1994, comb. n., H. jeekeli (Golovatch & Enghoff, 1994, comb. n., H. lingulatus (Liu, Golovatch & Tian, 2014, comb. n., H. laticollis (Liu, Golovatch & Tian, 2016, comb. n., H. longispinus (Loksa, 1960, comb. n., H. lui (Golovatch, Li, Liu & Geoffroy, 2012, comb. n., H. minutuberculus (Zhang, 1986, comb. n., H. nodulosus (Liu, Golovatch & Tian, 2014, comb. n., H. parvulus (Liu, Golovatch & Tian, 2014, comb. n., H. phasmoides (Liu, Golovatch & Tian, 2016, comb. n., H. pilosus (Attems, 1937, comb. n., H. proximus (Nguyen, Golovatch & Anichkin, 2005, comb. n., H. rhinoceros (Likhitrakarn, Golovatch & Panha, 2015, comb. n., H. rhinoparvus (Likhitrakarn, Golovatch & Panha, 2015, comb. n., H. scolopendroides (Golovatch, Geoffroy & Mauriès, 2010, comb. n., H. scutigeroides (Golovatch, Geoffroy & Mauriès, 2010, comb. n., H. similis (Liu, Golovatch & Tian, 2016, comb. n., H. simplex (Golovatch, VandenSpiegel & Semenyuk, 2016

Variações nos métodos de aplicação dos herbicidas Diuron e Tripluralin na cultura do algodoeiro Methods of application of the herbicides Diuron and Trifluralin in cotton

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Aldo Alves

1967-01-01

Full Text Available Foram estudados os efeitos das variações nos métodos de aplicação dos herbicidas Diuron e Trifluralin na cultura algodoeira, para verificar sua eficiência no combate às ervas daninhas. O tratamento Trifluralin aplicado em pré-plantio incorporado, provocou excelente combate às ervas daninhas gramíneas, porém irrisória redução da população das dicotiledôneas. A aplicação de Trifluralin em pré-plantio incorporado e a de Diuron em pré-emergência, aumentaram consideravelmente a área de contrôle nos dois grupos de ervas más. O tratamento Diuron aplicado em pré-emergência foi bastante efetivo no combate às ervas de "fôlhas largas", enquanto que no combate às gramineas não foi tão eficiente. O incorporação do Diuron, aplicado em pré-plantio, não aumentou a eficiência do produto químico. A redução da dose de Diuron em pré-plantio incorporado ou em pré-emergência não proporcionou combate adequado às ervas más.1 - An experiment to study the various modalities of the application of the herbicides diuron and trifluralin in cotton plantings was carried out in purple latosol soil, Chapadão series. The two herbicides were applied in various doses and at different times. The most common weeds in the trial area were capim pé-de-galinha (goosegrass, capim carrapicho (sandbur, capim colchão (crabgrass, beldroega (purslane, carraplcho de carneiro, and poaia. 2 - The effectiveness of diuron (1.60 kg/ha, applied pre-planting, was not increased by incorporation into the soil. The control of weeds was efficient, but the yield was inferior to that of plots without incorporation. Of the weeds that survived the treatment, a predominance of grass species was noted. Some of the cotton leaves turned yellow in plots that received this herbicide, but this chlorosis was temporary and the plants regained their normal color within a few weeks. The tolerance of cotton for the treatments did not appear to be affected by the method of

Screening of plant species as ground cover on uranium mill tailings

International Nuclear Information System (INIS)

Venu Babu, P.; Eapen, S.

2012-01-01

residual mill tailings apart from containing residual radionuclides do have the capacity to support good plant growth. Several species like Rhynchosia minima, Rhynchosia, Thysanolaena maxima, Mucuna pruriens, Desmanthus virgatus, Desmodium gangeticum, Clitoria tematea, Chrysopogon fulvus and Indigofera trita were found to be quite suitable for planting on mill tailings as ground cover while a few others that registered poor growth and/or biomass perhaps can be grown in combination with other species. On the contrary a few species viz., Bothriochloa pertusa, Cenchrus ciliaris, Panicum antidotale and Pennisetum caudatum were found to be unsuitable as they could not survive in mill tailings. A combination of several plant species tested in this study coupled with a few agronomic practices can be tried on mill tailings in Jaduguda as an appropriate vegetative cover. (author)

CATÁLOGO DE LA FAMILIA POACEAE EN COLOMBIA

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Diego Giraldo-Cañas

2011-01-01

Full Text Available Se presenta un inventario de las especies de Poaceae de Colombia junto con un análisis de la diversidad específica de esta familia según las regiones naturales colombianas, los gradientes de altitud y de precipitaciones, y la distribución sistemática. Se realizaron 96 expediciones de campo a las diez grandes regiones naturales de Colombia (Amazonia, Andes, Caribe, Chocó Biogeográfico, Guayana, islas caribeñas, Orinoquia, Sierra Nevada de Santa Marta, valle del río Cauca y valle del río Magdalena con un muestreo total de alrededor de 5800 ejemplares. Además, se consultaron colecciones de los herbarios CAUP, COAH, COL, CUVC, CHOCO, HFAB, HUA, HUQ, JAUM, MEDEL, MEXU, MO, NY, PSO, RSA, SI, UDBC, UIS, US, VALLE y VEN, y se realizó una investigación bibliográfica exhaustiva. Las Poaceae están representadas en Colombia por 840 especies y 173 géneros. Se reconocieron 74 especies y un género (Agrostopoa endémicos. Por otra parte, se documentaron 83 especies introducidas-naturalizadas y 50 introducidas-cultivadas. Los géneros más ricos en especies son Paspalum (89 especies, Panicum (42, Festuca (36, Eragrostis (29, Calamagrostis (25, Chusquea (25, Digitaria (24, Axonopus (21, Setaria (20, Cenchrus (18, Poa (17, Muhlenbergia (16, Andropogon (15, Aristida (15, Agrostis (14, Lasiacis (12, Urochloa (12, Pariana (11, Sporobolus (11, Arthrostylidium (10, Cortaderia (10, Nassella (10, Neurolepis (10 y Schizachyrium (10. Durante el desarrollo de esta investigación, se descubrieron 10 nuevos registros para la flora colombiana. La regiones Andina, Orinocense, Caribe y Guayanesa son las más ricas en especies, con 583, 233, 186 y 179 especies, respectivamente. La Región Andina presenta el mayor número de especies endémicas (57 especies. Los gradientes altitudinales más diversos corresponden a los de las tierras bajas (por debajo de 1200 m s.m.. Al igual que en otras áreas tropicales, en Colombia las subfamilias de Poaceae muestran una

Adubação orgânica da batata com esterco e, ou, Crotalaria juncea: II - disponibilidade de N, P e K no solo ao longo do ciclo de cultivo Organic fertilization of potato with manure and, or, Crotalaria juncea: II - soil N, P, and K availability throughout the growing season

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Tácio Oliveira da Silva

2007-02-01

Full Text Available Os solos do Agreste paraibano têm baixa fertilidade e a prática usual de adubação é a incorporação de esterco na época do plantio. Entretanto, dependendo da qualidade do esterco, essa prática pode causar a imobilização de nutrientes do solo durante os primeiros meses de cultivo. É possível que o cultivo e incorporação de Crotalaria juncea, combinado com o esterco, possa promover mineralização mais sincronizada com a demanda de nutrientes pelas plantas. No presente estudo, realizado em 2003, foram conduzidos experimentos de campo e em casa de vegetação para testar essa hipótese. As parcelas de campo foram previamente cultivadas com batata no período de 1996 a 2002 e submetidas anualmente aos seguintes tratamentos: plantio e incorporação da crotalária na época da floração (C; adição de 15 t ha-1 de esterco (E; plantio e incorporação de crotalária + 7,5 t ha-1 de esterco (CE; e testemunha, sem esterco ou crotalária (T. Em 2003, foram aplicados os mesmos tratamentos de adubação orgânica e foi avaliada a dinâmica da decomposição e liberação de nutrientes pelo material vegetal e esterco contidos em sacolas de náilon incorporadas ao solo das parcelas de campo. Também se avaliou a dinâmica da disponibilidade de N, P e K no solo das parcelas de campo, por meio de coletas periódicas de solo. No ensaio em casa de vegetação, foram realizados cultivos sucessivos de capim-buffel (Cenchrus ciliaris L. por um período de 300 dias, utilizando-se amostras do solo das parcelas de campo. As perdas de massa e nutrientes do material incorporado ao solo foram maiores nos primeiros 30 dias da incubação, em todos os tratamentos. No final do ensaio, as proporções de matéria seca e nutrientes remanescentes foram maiores nos tratamentos E e CE que nos tratamentos C e T. No solo das parcelas de campo, o tratamento E aumentou os teores de P e K extraíveis (Mehlich-1 do solo ao longo do período do estudo, porém provocou a

Manejo de plantas daninhas na cultura do algodoeiro em sistema de plantio direto Weed management of cotton under no-tillage

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R.S. Freitas

2006-06-01

Full Text Available Este trabalho foi realizado com objetivo de avaliar a eficiência dos herbicidas smetolachlor, em pré-emergência, e trifloxysulfuron-sodium, aplicado aos 18 dias após a emergência do algodão (DAE, em sistema de plantio direto. Foi utilizado o arranjo fatorial (4 x 4 + 1, sob delineamento de blocos casualizados, com quatro repetições. O primeiro fator constituiu-se de quatro doses de S-metolachlor (0, 384, 768 e 1.152 g ha-1 e o segundo de quatro doses de trifloxysulfuron-sodium (0,0; 2,625; 5,250; e 7,875 g ha-1, mais uma testemunha mantida no limpo por todo o ciclo do algodoeiro. As plantas daninhas foram avaliadas aos 25, 45 e 60 DAE. Na área, foi verificada a presença das seguintes espécies daninhas: Alternanthera tenella (apaga-fogo, representando mais de 80% do total, Tridax procumbens (erva-de-touro, Bidens sp. (picão-preto, Acanthospermum hispidum (carrapicho-de-carneiro, Cenchrus echinatus (capim-carrapicho, Digitaria horizontalis (capimcolchão, Eleusine indica (capim-pé-de-galinha e Commelina benghalensis (trapoeraba. O S-metolachlor apresentou baixa eficiência de controle destas espécies, no entanto o trifloxysulfuron-sodium teve seu desempenho melhorado quando foi aplicado S-metolachlor. O melhor controle foi obtido com a combinação de S-metolachlor a 1.152 g ha-1 com trifloxysulfuron-sodium a 7,875 g ha-1, que apresentou controle superior a 90% de A. tenella e do total de plantas daninhas até 60 DAE. Todavia, esse controle não foi suficiente para permitir a colheita do algodão no limpo. As combinações de S-metolachlor a 384 e 768 g ha-1 com trifloxysulfuron-sodium a 7,875 g ha-1 e de S-metolachlor a 1.152 g ha-1 com trifloxysulfuron-sodium nas doses de 5,250 e 7,875 g ha-1 proporcionaram rendimentos semelhantes aos da testemunha capinada.The objective of this study was to evaluate the efficiency of the herbicides Smetolachlor in pre-emergence and trifloxysulfuron-sodium applied 18 days after crop emergence (DAE

Changes in organic matter (C, N and P) of soils under subsistence agriculture; Mudancas na materia organica (C, N e P) de solos sob agricultura de subsistencia

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Fraga, Vania da Silva

2002-10-01

-CO{sub 2} produced during three days of incubation (C-min3d); C oxidized with 333 mM (C-ox 333) and 16,5 mM (C-ox16) KMnO{sub 4}. The only fraction that did not correlate with total C was C-fl. Average proportions of total C extracted by C-mins3d, C-ox 16 were 1.5%, 24% and 7.2 %, respectively. In the second phase, the whole sample set (n=160) was analyzed for C-ox16. This C fraction decreased from 1.65 g kg{sup -1} under UDF to 0.70 in DC (P<0.05). However, the change in SOM lability for the same comparison was small. Lability, defined as the ratio (C-ox16/non-oxidized C)*100, declined from 10.3% to 8.5% with increased land use intensity; although this declines suggested a change in SOM quality, it was statistically significant. Carbon management indexes (CMI) , based on changes in C concentrations and in C lability in comparison with UDF (CMI=100), decreased to 67% in DDF and 47% in DC. These decreases were more related to decreases in C concentrations than in its lability. The experiment assessed the effect of SOM changes in the nutrient supplying power (N and P), by selecting 20 samples that varied in their C content from 9.19 to 21.8 g kg{sup -1}, in a pot experiment. Total C correlated significantly with N mineralized in 60 d (N-min60d) (r=0.79***) while N-min60 and P-Mehlich-1 explained 80% of the variation in dry matter production by buffel grass (Cenchrus ciliaris). Low P availability, C and N losses, limited water availability and sometimes-inappropriate land management techniques, are considered strong limiting conditions for the recovery of degraded soils by traditional bush fallow techniques. (author)

Use of local pastoral species to increase fodder production of the saline rangelands in southern Tunisia

Science.gov (United States)

Tlili, Abderrazak; Tarhouni, Mohamed; Cardà, Artemi; Neffati, Mohamed

2017-04-01

Climate changes associated with multiple destructive human activities accelerate the degradation process of the natural rangelands around the world and especially the vulnerable areas such as the dryland ecosystems (Anaya-Romero et al., 2015; Eskandari et al., 2016; Muños Rojas et al., 2016; Vicente-Serrano et al., 2016). The vegetation cover and the biomass production of these ecosystems are decreasing and this is resulting in land degradation due to the soil erosion and changes in soil quality due to the abuse and misuse of the soil resources (Cerdà et al., 2016; Prosdocimi et al., 2016; Keesstra et al., 2016). To cope with such threats, it is necessary to develop some management techniques (restoration, plantation…) to enhance the biomass production and the carbon sequestration of the degraded rangelands (Muñoz-Rojas et al., 2016; Tarhouni et al., 2016). The valorization of saline water by planting pastoral halophyte species in salt-affected soils as well as the marginal areas are considered among the valuable tools to increase the rangeland production in dry areas. In this work, the ability of four plants (Atriplex halimus L. (Amaranthaceae), Atriplex mollis Desf. (Amaranthaceae), Lotus creticus L. (Fabaceae) and Cenchrus ciliaris L. (Poaceae)) to grow and to produce are tested under a field saline conditions (water and soil). Non-destructive method (Vegmeasure) is used to estimate the biomass production of these species. Chemical (crude protein, moisture and ash contents) and biochemical analyses (sugars, tannins and polyphenols contents) are also undertaken. Two years after plantation, the obtained results showed the ability of the four species to survive and to grow under high salinity degree. A strong positive correlation was obtained between the canopy cover and the dry biomass of the four studied species. Hence, the restoration of saline soils can be ensured by planting local halophytes. Acknowledgements. The research leading to these results has

7ª Contribuição ao estudo dos Flebotomus (Diptera: Psychodidae: descrição dos machos de 24 novas espécies

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O. Mangabeira Filho

1942-01-01

Full Text Available The A. and his co-workers captured in trips in the hinterland of Brazil more tham 17.000 flebotomi from which 35 are new ones, 11 discribed by, him in previous papers. The A. found these insects in groups of species living in different habitats, some ones of them not yet known: ondoors, or outdoors attracted by light or animal baits, without Shannon’s trap, in great or small caves, in the jungle in tree’s holes, holes in stones, holes in the soil habited by animals like armadillos, pacas (Aguti paca, wild rats, cururú toad (Bufo sp.. He observed the life history of 13 species: Flebotomus longipalpis Lutz& Neiva, 1912, Flebotomus intermedius Lutz & Neiva, 1912, Flebotomus avellari Costa Lima, 1932, Flebotomus aragãoi costa Lima, 1932, Flebotomus lutzianus Costa Lima, 1932, Flebotomus limai fonseca, 1935, Flebotomus rickardi Costa Lima, 1936, Flebotomus dasipodogeton Castro, 1939, Flebotomus oswaldoi n. sp., Flebotomus villelai n. sp., Flebotomus triacanthus n. sp., Flebotomus longispinus n. sp. And flebotomus travassosi n. sp. He describes the male of 24 n. sp., explaining the differential diagnose of group or nearly allied species. He inclued F. rooti n. sp. And F. hirsutus n. sp. In the sub-genus Shannonomyia. The first one, very allied to F. davisi Root is different from it, for presenting in the dorsal side of the abdomen bristles and not scales and to have the median claspers longer than his inner appendage and F. hirsutus quite different from the others which show 3 spines on distal segment of the upper clasper and for being the only one who presents the bristles of inner appendage of median clasper longer than it. Only the females of F. amazonensis Root and f. chagasi Costa Lima, are known and then it is possible that they belong to one of the species of this sub-genus from whom only the male have been described. F. choti Floch & Abonnenc, captured also at Pará, F. triacanthus n. sp. F. trispinosus n. sp. And F. equatorialis n. sp