Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Atividade residual de (imazethapyr+imazapic) sobre azevém anual (Lolium multiflorum), semeado em sucess?o ao arroz irrigado, sistema clearfield?
Pinto, J.J.O.;Noldin, J.A.;Rosenthal, M.D.;Pinho, C.F.;Rossi, F.;Machado, A.;Piveta, L.;Galon, L.;
Planta Daninha , 2009, DOI: 10.1590/S0100-83582009000300023
Abstract: the aim of this study was to evaluate the residual activity of the prepackage mix of the herbicide only (imazethapyr+imazapic) in a clearfield (cl) rice production system during one, two or three rice seasons. the study was carried out in the field at centro agropecuário da palma/universidade federal de pelotas, rio grande do sul, southern brazil. ryegrass (lolium multiflorum) was planted after cl rice, cv. irga 422 cl. cl rice was considered as the main crop (summer) and ryegrass was planted following cl rice. the experimental design was a randomized complete block, with four replications. the treatments were arranged as a factorial: factor a, during the same season, compared herbicide residues during one, two or three years of cl rice and factor b, for herbicide rates. herbicide (imazethapyr+imazapic) was applied at (0; 25+75; 37,5+112,5; 50+150) g ha-1 with surfactant dash being added at 0.5% v/v. the results showed interaction between cl rice seasons and the herbicide rate for the variables plant height and biomass. all variables tested were affected by herbicide (imazethapyr+imazapic) residue and the effect was more severe at higher rates. grain weight and germination percentage were only affected by the herbicide rates. the results showed also that the residue of herbicides (imazethapyr+imazapic) applied to cl rice may stay in the soil and affect ryegrass plants cultivated following cl rice. cl rice production system with herbicides (imazethapyr+imazapic) requires periods longer than 180 days for planting ryegrass as a successional crop.
Comportamento ingestivo e desempenho de ovinos em pastagem de azevém anual (Lolium multiflorum Lam.) com diferentes massas de forragem
Roman, Juliano;Rocha, Marta Gomes da;Pires, Cleber Cassol;Elejalde, Denise Adelaide Gomes;Kloss, Mircon Giovani;Oliveira Neto, Renato Alves de;
Revista Brasileira de Zootecnia , 2007, DOI: 10.1590/S1516-35982007000400005
Abstract: the objective of this trial was to evaluate ingestive behaviour and performance of sheep grazing italian ryegrass (lolium multiflorum lam.) pasture with different herbage mass (hm): low hm: 1,000 - 1,200 kg/ha of dm (lhm); medium hm: 1,400-1,600 kg/ha dm (mhm); high hm 1,800-2,000 kg/ha dm (hhm). a completely randomized design with three treatments and two replicates (paddocks) per treatment was used. data were submitted to polynomial regression analysis in function of the actual hm observed in each experimental unit: 1,136.8, 1,190.9, 1,359.2, 1,375, 1,556, and 1,739.1 kg/ha dm. leaf blade and pseudostem masses, forage and leaf blade allowances, sward and pseudostem heights, leaf blade depth, and average daily gain all increased linearly from lhm to hhm while the opposite was observed for stocking and bite rates. however, no hm effect was found for herbage intake, times spent grazing, ruminating and idle, amount of daily bite, bite mass, body condition score gain, body weight gain per hectare, and feed efficiency. the range of hm evaluated showed no differences in body weight gain per hectare with similar conversion efficiency of forage in animal product. the depth of leaf blade layers is the most important variable affecting sheep performance.
Características morfogênicas de azevém anual (Lolium multiflorum Lam.) sob pastejo em sistemas intensivos de utiliza??o
Edna Nunes, Gon?alves;Quadros, Fernando Luiz Ferreira de;
Ciência Rural , 2003, DOI: 10.1590/S0103-84782003000600020
Abstract: the experiment was carried out to characterize the morphogenic response of lolium multiflorum cv. "comum" in intensive utilization systems using nitrogen (n) fertilizer range from 90 to 180kg.ha-1 of n, in mixture or not with arrowleaf clover. the experiment was conducted in an area of the department of animal science of the universidade federal de santa maria, brazil, from july 20th to september 23th, 2002. beef heifers were used in continuous grazing with variable stocking rate using put and take technique for the adjustment of the stocking rate to a herbage allowance of 10% of the live weight. to evaluate the dynamics growth of the species, the marked tillers techniquewas used. the experimental design was complete randomized with 63 repetitions. the following treatments were used: italian ryegrass + oat + 180kg.ha-1 of n (n180); italian ryegrass + oat + 90kg.ha-1 of n + supplementation (n90+s); italian ryegrass + oat + 120kg.ha-1 of n + arrowleaf clover (n120+ac). the animals of the treatment n90+s were supplemented with ground sorghum grain at 1% of the live weight. the leaves appearance rate (lar), leaves elongation rate (ler) and leaves lifespan (ll) were evaluated. treatments receiving the highest n level (n180 and n120+ac) had in the first period higher ler. the treatment n90+s showed similar result (4,95 mm.tiller-1.day-1) only in the second period. in an average of two periods, there was not a significant difference between treatments. the treatment n120+ac had larger ll and lower lar in the first period than the others, and it didn't differ of these in the last period. in conclusion, intensive systems of utilization of sward with levels from 90 to 180kg.ha-1 of n, in mixture or not with arrowleaf clover in grazing conditions, didn't affect the morphogenic characteristic of ryegrass.
Características morfogênicas de azevém anual (Lolium multiflorum Lam.) sob pastejo em sistemas intensivos de utiliza o  [cached]
Edna Nunes Gon?alves,Quadros Fernando Luiz Ferreira de
Ciência Rural , 2003,
Abstract: O experimento foi conduzido em área do Departamento de Zootecnia da Universidade Federal de Santa Maria, regi o Central do Rio Grande do Sul, Brasil, para caracterizar a resposta morfogênica de Lolium multiflorum, cv. Comum, em sistemas intensivos de utiliza o da pastagem, numa faixa de aduba o nitrogenada de 90 a 180kg.ha-1 de N, em consorcia o ou n o com trevo vesiculoso, no período de 20/07 a 23/09 de 2000. Foram utilizadas terneiras de corte em pastejo contínuo, com lota o variável, com a utiliza o da técnica de animais reguladores para o ajuste da carga animal a uma oferta de 10% do peso vivo. Para o acompanhamento da dinamica de crescimento da espécie, foi utilizada a técnica dos afilhos marcados. O delineamento experimental utilizado foi o inteiramente casualizado com 63 repeti es. Foram adotados os seguintes tratamentos: azevém + aveia + 180kg.ha-1 de N (N180); azevém + aveia + 90kg.ha-1 de N + Suplementa o (N90+S) e; azevém + aveia +120kg.ha-1 de N + trevo vesiculoso (N120+TV). Aos animais do tratamento com N90+S, foi fornecida suplementa o com sorgo moído a 1% do peso vivo. Foram avaliadas a taxa de surgimento de folhas (folhas.afilho-1.dia-1), a taxa de elonga o de folhas (mm.afilho-1.dia-1) e a dura o de vida das folhas (graus-dia). Os afilhos de azevém dos tratamentos que receberam as maiores doses de nitrogênio (N180 e N120+TV) tiveram no primeiro período uma maior taxa de elonga o, enquanto N90+S somente alcan ou resultado semelhante, de 4,95mm.afilho-1.dia-1, no segundo período, fazendo com que, na média dos dois períodos, n o houvesse diferen a significativa. No tratamento N120+TV, os afilhos tiveram uma dura o de vida de folhas superior e uma taxa de surgimento de folhas inferior no primeiro período em rela o aos demais tratamentos e n o diferiu destes no último período. Com isso, pode-se concluir que a escolha por sistemas intensivos de utiliza o da pastagem através de doses de 90 a 180 kg.ha-1 de N e a consorcia o ou n o com trevo vesiculoso, em condi es de pastejo, n o afetou as características morfogênicas de azevém.
Somatic embryogenesis in Lolium multiflorum suspension culture
Margarita Pavlova,Elizabeth Kordyum
Acta Societatis Botanicorum Poloniae , 1996, DOI: 10.5586/asbp.1996.007
Abstract: The embryogenic cell suspension was obtained from immature embryos of Lolium multiflorum through a callus culture. Somatic embryogenesis was induced by addition of 2,4-D, dicamba and picloram in 0,5 mg/l concentrations in MS liquid nutrient medium. It was shown that somatic embryos arised from single cells. In globular embryoids, the meristematic cells are characterized by the presence of phytoferritin inclusions in the leucoplasts.
Morphology and pollen viability of Lolium multiflorum Lam.
Nunes, Renata de Castro;Bustamante, Fernanda de Oliveira;Techio, Vania Helena;Mittelmann, Andréa;
Ciência e Agrotecnologia , 2012, DOI: 10.1590/S1413-70542012000200006
Abstract: study and characterization of pollen grains are essential for different areas, especially taxonomy, genetic improvement, phylogeny, and paleobotany. as yet, there are no reports on pollen morphology of genotypes of naturalized lolium multiflorum lam., introduced cultivars or breeding populations, diploid or polyploid. ten genotypes of annual ryegrass (l. multiflorum) were evaluated for the viability of pollen grains using propionic carmine and alexander's stains, while morphology was assessed by the acetolysis technique. measures of polar axis (p), equatorial diameter (e), exine thickness, and analysis of pollen grains were obtained by scanning electron microscopy (sem). all genotypes showed high rate of pollen viability (> 89%) for both stains. there were differences between genotypes in the following quantitative traits: polar axis, equatorial diameter, exine, endexine, ektexine, and p/e ratio. pollen grains were characterized as small, monoporates, with circular and non-prominent apertures. in addition to helping distinction of pollen grains, morphometric differences can be used later to compare ploidy levels, thus assisting in breeding programs of the species.
Análisis de la sensibilidad de biotipos de Lolium multiflorum a herbicidas inhibidores de la enzima ALS, ACCasa y Glifosato Sensitivity analysis of Lolium multiflorum biotypes to Glyphosate, ACCase and ALS-inhibiting herbicides
P. Diez De Ulzurrun,M.I. Leaden
Planta Daninha , 2012, DOI: 10.1590/s0100-83582012000300024
Abstract: A pesar de los avances logrados en el control de las malezas con el uso de herbicidas, el manejo de las mismas no se simplificó, sino que, al contrario, surgieron nuevos desafíos, como la aparición de resistencia a herbicidas. En 2007, se reportó en Lolium multiflorum el segundo caso de resistencia a glifosato detectado en Argentina. En el sudeste de la provincia de Buenos Aires se registraron fallas de control a campo en poblaciones de Lolium multiflorum debido a su resistencia a distintos herbicidas de las familias de los inhibidores de ALS y de ACCasa y al herbicida glifosato. El objetivo de este estudio fue caracterizar el nivel de resistencia a ciertos herbicidas inhibidores de la ALS y de la ACCasa y al glifosato en una población de L. multiflorum de Lobería (Bs As, Argentina) supuestamente resistente (LmR). Se realizaron bioensayos en cajas de Petri y se determinó la GR50 mediante la variación en la longitud de coleoptile. Las curvas de dosis-respuesta se obtuvieron por medio de la ecuación log-logística. El biotipo LmR presentó resistencia múltiple a herbicidas con tres modos de acción diferentes: glifosato, inhibidores de ALS y de ACCasa. Dicho ensayo demostró la aparición de un biotipo de L. multiflorum con resistencia a múltiples principios activos. Despite progress in weed control using herbicides, management has not been simplified, but new challenges such as herbicides resistance have arisen. In 2007, a Lolium multiflorum population resistant to glyphosate was reported, as the second case of glyphosate resistant weeds in Argentina. In the southeast of Buenos Aires province, control failures in populations of L. multiflorum to different families of herbicide such as ALS and ACCase inhibitors and to glyphosate at field level have been registered. The aim of this study was to characterize the level of resistance to certain herbicides inhibitors of ALS, ACCase and glyphosate in a putatively resistant (LmR) population of L. multiflorum of Loberia (Buenos Aires, Argentina). Bioassays were conducted in Petri dishes and the GR50 was determined by the length of coleoptile. Curves dose-response were obtained using the log-logistic equation. The LmR biotype survived under multiple herbicides of three different modes of action, glyphosate, ALS and ACCase inhibitors. This test showed the appearance of a biotype of L. multiflorum with resistance to multiple active ingredients.
Competi o de azevém (Lolium multiflorum L. ) com duas cultivares de trigo Ryegrass (Lolium multiflorum L. ) competition with two wheat cultivars
N.G. Fleck
Planta Daninha , 1980, DOI: 10.1590/s0100-83581980000200001
Abstract: Com os objetivos de avaliar a habilidade de duas cultivares de trigo em competir com azevém (Lolium multiflorum, L.) e de estimar os efeitos da concorrência de várias densidades desta espécie sobre a cultura, foi conduzido experimento a campo durante a esta o de crescimento de 1978, na Esta o Experimental Agron mica da UFRGS, em Guaíba, RS. Foram comparadas as cultivares de trigo 'E-7414' e 'PAT-7219', na popula o de 300 plantas por m', com azevém semeado nas densidades de 0, 2,5, 5,0, 10,0 e 20,0 kg/ha, as quais originaram popula es médias de 0, 130, 210, 470 e 750 plantas por m2 , respectivamente. A competi o entre as espécies foi mantida durante o ciclo da cultura. Para o rendimento de gr os da cultivar 'E-7414', a competi o exercida pelo azevém ocasionou decréscimos variáveis entre 18% e 56%, dependendo da infesta o; enquanto para a cultivar 'PAT-7219', as redu es no rendimento de gr os se situaram entre 4c é 22%, conforme a densidade do azevém. Enquanto para 'PAT-7219' n o foram significativas as redu es no rendimento de gr os, para `E-7414' os decréscimos verificados alcan aram significancia estatística. A análise do peso da matéria seca do azevém demonstrou que este aumentou proporcionalmente ao aumento de sua popula o, mas que aquela variável foi significativamente menor quando o azevém esteve competindo com 'PAT-7219' do que com `E-7414'. Em média, diminuiu em 31% a matéria seca do azevém produzida sob 'PAT-7219' em rela o à `E-7414'. A field experiment was conducted to evaluate the ability of two wheat cultivars to compete with ryegrass (Lolium multiflorum L.), and to estimate the competition effects of various densities of this species on the crop, at the Agronomy Experimental Station, in Guaiba, RS, during the 1978 wheat growing season. Two wheat cultivars ('E-7414' and 'PAT-7219') were grown in competition with ryegrass at the densities of 0, 130, 210, 470, and 750 plants per m'. The competition effects were maintained during the whole wheat cycle. Depending on the weed population, ryegrass competition caused significant decreases, varying from 18 to 56%, in seed yield of the wheat cultivar `E-7414'; whereas, for `PAT-7219' cultivar, although seed yield reductions varied from 4 to 22% , were not statistically significant. Ryegrass dry matter production increased proportionally to its population. However, ryegrass dry matter yield was significantly lower whe n this specie s competed with 'PAT-7219' wheat cultivar than with 'E-7414'. As an average for the established densities, ryegrass dry matter produced in competi tion with 'PAT
The effect of different condensed phosphates on the yield of Lolium multiflorum and their effect on different interrelations  [cached]
Notulae Botanicae Horti Agrobotanici Cluj-Napoca , 1978,
Abstract: The condensed phosphates such as ammonium pyrophosphate, potassium, metaphosphate, ammonium polyphosphates are among the newest achievements in the domain of fertilizers (5, 6). Results of various experiments have shown that these fertilizers increase the yield in wheat, barley, maise, potato, sugar beat, bean and others (2, 3, 5). However, experiments in this field are few (3). In Lolium multiflorum the reactions of these forms of phosphorus were not illustrated in many cases, because the experiments had been carried out with salts of NH4, K and Ca, where the effect was combined. The objective of this report is to present results of a series of greenhouse pot experiments.
Effect of organic contaminants on seed germination of Lolium multiflorum in soil  [PDF]
DL Korade,MH Fulekar
Biology and Medicine , 2009,
Abstract: The seed germination trials have relevance in selection of the plants for their prospective use inphytoremediation. The effect of organic contaminants; anthracene and chlorpyrifos on the seedgermination of Lolium multiflorum (ryegrass) has been investigated. The germination of ryegrass seedswas evaluated in the separately spiked soil with organic compounds at the concentrations 10, 25, 50, 75and 100 mg/kg while un-spiked soil taken as control. There was no inhibitory effect of anthraceneobserved on germination as compared to the control whereas significant reduction and delay in seedgermination was observed at the higher chlorpyrifos concentrations of 75 and 100 mg/kg. The resultsshow the pesticide (chlorpyrifos) toxicity was not caused to the ryegrass seeds up to the concentrationof 50 mg/kg. The level of seed germination was found to decrease with increasing concentrations ofchlorpyrifos in the soil. The findings of this study assessed ability of ryegrass seeds to survive andtolerate the contaminants for phytoremediation studies.
Page 1 /100
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.