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Search Results: 1 - 10 of 17418 matches for " Valterley Soares Rocha "
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AVALIA O DOS ESTáGIOS FENOLóGICOS DE CULTIVARES DE SORGO FORRAGEIRO EM DIFERENTES éPOCAS DE SEMEADURA EVALUATION OF PHENOLOGICAL STAGES OF FORAGE SORGHUM CULTIVARS IN DIFFERENT SOWING TIMES
Alessandro Guerra da Silva,Valterley Soares Rocha
Pesquisa Agropecuária Tropical , 2007, DOI: 10.5216/pat.v36i2.2147
Abstract: A fim de obter informa es sobre o comportamento do sorgo forrageiro em diferentes épocas de semeadura, efetuou-se um grupo de ensaios no campo experimental do Departamento de Fitotecnia da Universidade Federal de Vi osa, durante o ano agrícola 1999/2000. Oito ensaios foram conduzidos, sendo iniciados na primeira quinzena do mês de outubro de 1999 até maio de 2000. O delineamento experimental utilizado, em cada ensaio, foi o de blocos casualizados com quatro repeti es. As cultivares de sorgo usadas foram: AG 2002, BR 501, BR 506, BR 601, BR 602 e BR 700 (forrageiros), AG 2005E e Massa 03 (duplo propósito) e AG 2501C e BRS 800 (corte e pastejo). Os estágios fenológicos (diferencia o floral, florescimento e matura o) de cada cultivar foram avaliados em cada época de semeadura. Os resultados obtidos permitiram concluir que as cultivares AG 2002, BR 501, BR 601, BR 602 e BR 700 apresentaram sensibilidade ao fotoperíodo, enquanto AG 2005E, AG 2501C, BR 506, BRS 800 e Massa 03 foram insensíveis. O decréscimo da temperatura ocasionou o atraso do desenvolvimento fenológico de todos os cultivares e a eleva o antecipou o ciclo das cultivares. PALAVRAS-CHAVE: Sorghum bicolor; fotoperíodo; cultivar; forragem; temperatura. To obtain information about the behavior of forage sorghum in different sowing times, a group of trials was set up in the experimental field of the Department of Plant Science, Universidade Federal de Vi osa, Minas Gerais State, Brazil during the 1999/2000 growing season. Eight experiments were used, starting in the first fortnight of October 1999 through May 2000. Each experiment was arranged in randomized blocks with four replications. The sorghum cultivars used were: AG 2002, BR 501, BR 506, BR 601, BR 602 and BR 700 (forage), AG 2005E and Massa 03 (dual purpose) and AG 2501C and BR 800 (cutting and grazing). The phenological stages (floral differentiation, flowering and maturation) for each cultivar were evaluated for each sowing time. It was concluded that the cultivars AG 2002, BR 501, BR 601, BR 602, and BR 700 were sensitive to photoperiod, while AG 2005E, AG 2501C, BR 506, BRS 800, and Massa 03 were insensitive. The temperature decrease caused a delay in the phenological development for all cultivars, while the increaseadvanced the cycle. KEY-WORDS: Sorghum bicolor; photoperiod; cultivar; forage; temperature.
Desempenho de genitores e popula??es segregantes de trigo sob estresse de calor
Oliveira, Davi Melo de;Souza, Moacil Alves de;Rocha, Valterley Soares;Assis, Josiane Cristina de;
Bragantia , 2011, DOI: 10.1590/S0006-87052011000100005
Abstract: the expansion of wheat crops to areas with higher temperatures, like the central-brazil, is one of the main actions to decrease the wheat importation. for this reason, heat tolerant genotypes are essentials. the objective of this study was to identify genetic variability for heat tolerance, to identify heat tolerant wheat populations and genitors, and to quantify the high temperature effects on those wheat genotypes. two experiments were carried out in vi?osa, minas gerais state. a 16x16 square lattice design was used with two replications, where 240 families from eight segregating populations (30 families from each population) plus 16 genitors were evaluated. in the first experiment sowed in february 2007 (summer), f2:4 families were evaluated. in the second one sowed in june 2007 (winter), f2:5 families were evaluated. the flowering, plant height, grain yield, and thousand grain weight were evaluated. different temperature conditions from emergence to flowering were crucial on genotype responses when compared the two environments. there was found genetic variability for heat tolerance between wheat genitors and segregating populations. all the evaluated traits presented reduction under high temperatures, being the grain yield the most affected, followed by plant height, flowering, and thousand grain weight. the genitors br 24, alian?a, and ep 93541 and the populations bh1146/br24//alian?a/ep93541, br24/alian?a//ep93541/cpac9662 and alian?a/ep93541//cpac9662/pioneiro were the most heat resistant.
Análise de trilha para componentes do rendimento e caracteres agron?micos de trigo sob desfolha
Gondim, Tania Cristina de Oliveira;Rocha, Valterley Soares;Sediyama, Carlos Sigueyuki;Miranda, Glauco Vieira;
Pesquisa Agropecuária Brasileira , 2008, DOI: 10.1590/S0100-204X2008000400007
Abstract: the objective of this work was to evaluate the influence of yield components and plant characters in grain production, in wheat under defoliation, through correlations decomposition using path analysis. the experiment was accomplished in vi?osa, mg, brazil, in 2004. the treatments consisted of three levels of defoliation and a control, with three wheat varieties - anahuac, brs 207 and br 24 -, with four replicates. defoliation was carried out by removing the blade of flag leaves from the second and third top leaves. the following parameters were evaluated: grain yield, hectolitric weight, one thousand-grain weight, number of spikes per plot, number of grain per spike, culm dry biomass, spike-straw dry biomass, total dry biomass, grain yield per spike, total dry biomass of individual culm, straw dry biomass of individual spike and total dry biomass per individual plant. the reduction in culm dry biomass led to lower losses of grain yield because of the higher remobilization of photoassimilates with defoliation. thousand-grain weight and number of grain per spike were the main yield components. the direct selection for these characters is an efficient strategy to increase grain yield in wheat under defoliation.
Tolerancia ao estresse térmico em genótipos de trigo
Cargnin, Adeliano;Souza, Moacil Alves de;Rocha, Valterley Soares;Machado, Juarez Campolina;Piccini, Edvandro;
Pesquisa Agropecuária Brasileira , 2006, DOI: 10.1590/S0100-204X2006000800009
Abstract: the objective of this work was to verify the effect of thermic stress conditions on the wheat culture, to evaluate the tolerance level of parents and segregant populations to these conditions, as well as to identify promising populations in order to obtain lines adapted to the brazilian central region. a circulant dialel was used among eight parents, comprising the cultivars alian?a, anahuac, bh 1146, br 24, brs 207 and pioneiro; and the lines cpac 9662 and ep 93541. thirty f2:4 families descending from the eight segregant populations and the eight genitors were evaluated. experiments were carried out in the field and the sowings were performed in the summer (heat stress condition) and winter (favorable condition) of 2004. the lattice design with two replicates was used. days to heading, plant height, average grain weight, and grain yield were evaluated. in the summer, high temperature reduced all characters evaluated, and thermic stress effects were determined by that reduction percent in comparison to winter cropping values. differences among genotypes in both sowing dates were also observed. the most heat-tolerant materials were the parents anahuac, bh 1146, br 24 and ep 93541, and the segregant populations alian?a/ep 93541, ep 93541/cpac 9662, and bh 1146/br 24.
Qualidade fisiológica de sementes de linhagens de soja com presen?a ou ausência de lipoxigenases, em diferentes épocas de colheita
Gondim, Tania Cristina Oliveira;Sediyama, Carlos Sigueyuki;Rocha, Valterley Soares;Moreira, Maurílio Alves;
Revista Brasileira de Sementes , 2002, DOI: 10.1590/S0101-31222002000100020
Abstract: soybean consumption as food is still limited due to its characteristic flavor and odor that have as the main cause the lipoxygenases enzymes. to avoid this problem, the soybean genetic improvement program of the federal university of vi?osa developed lines with the absence of the three forms of lipoxygenases in the grains. the present work was performed to evaluate the effect of the genetic elimination of lipoxygenases on physiological seed quality of four varieties, harvested at different periods. seeds of cac-1, doko-rc, ufv-16 and cristalina varieties and their respective derived lines with absence of three lipoxygenases, called triple-null, were multiplied in the field and the seeds were harvested at the r8 stage and 15, 30 and 45 days after the first harvest. later, the seeds were submitted to the germination test, first germination counting test, sand bed germination, accelerated aging and seedling emergence. it was observed that the fourth harvesting time showed highest differences among varieties and materials with or without lipoxygenases. it was concluded that the introduction of genes that condition the absence of the three lipoxygenases in the seeds, in the four varieties, produced lines of soybean with seeds of equal or poorer physiological quality, than that of the original varieties, depending on the studied variety, indicating a lack of direct relation between physiological quality and presence of lipoxygenases in the seeds.
COMPOSI O MINERAL DE GR OS DE TRIGO SUBMETIDOS A DOSES DE SULFATO DE AM NIO E TRINEXAPAC-ETIL MINERAL COMPOSITION OF WHEAT GRAINS SUBJECTED TO AMMONIUM SULFATE AND TRINEXAPAC-ETHYL RATES
Marcelo Curitiba Espindula,Marcela Campanharo,Valterley Soares Rocha,Pedro Henrique Monnerat
Pesquisa Agropecuária Tropical , 2010, DOI: 10.5216/pat.v40i4.6928
Abstract: A composi o mineral de gr os é importante para a defini o da qualidade nutricional do alimento e qualidade fisiológica das sementes, devendo ser considerada no estabelecimento dos níveis adequados de aduba o. Neste contexto, objetivou-se, com este estudo, avaliar o efeito de doses de sulfato de am nio (SA) e de trinexapac-etil, na composi o mineral de gr os de trigo (Triticum aestivum L.) cv. Pioneiro. O experimento foi desenvolvido em Vi osa (MG), no período de junho a outubro de 2006. Os tratamentos foram cinco doses de SA (150 kg ha-1, 300 kg ha-1, 450 kg ha-1, 600 kg ha-1 e 750 kg ha-1), combinadas com quatro doses de trinexapac-etil (0 g ha-1; 62,5 g ha-1; 125 g ha-1; e 187,5 g ha-1). O experimento foi instalado em delineamento de blocos casualizados, com quatro repeti es. As doses de SA aumentaram as concentra es de N-total (proteína), Ca, S, Cu e Zn e diminuíram as concentra es de P, K e Mn (acima de 457 kg ha-1de SA). Os teores de Mg e Fe n o foram influenciados pelas doses de SA. O trinexapac-etil promoveu aumento de N-total, P e Mn e redu o de Ca. Os teores de K, S, Cu, Zn, Mg e Fe n o foram influenciados pelo redutor. Conclu
Efeitos de reguladores de crescimento na elonga o do colmo de trigo = Effect of growth regulators on wheat stem elongation
Marcelo Curitiba Espindula,Valterley Soares Rocha,Leandro Torres de Souza,Moacil Alves de Souza
Acta Scientiarum : Agronomy , 2010,
Abstract: Objetivou-se com este trabalho avaliar o efeito de doses e épocas deaplica o de três reguladores de crescimento na elonga o do colmo de plantas de trigo. O experimento, conduzido em Vi osa, Estado de Minas Gerais, de maio a setembro de 2005, foi instalado com tratamentos em esquema fatorial e hierárquico com uma testemunha, no delineamento em blocos casualizados com quatro repeti es. Os tratamentos foram 500; 1.000 e 1.500 g ha-1 de clormequat; 62,5; 125,0 e 187,5 g ha-1 detrinexapac-etil e 40; 80 e 120 g ha-1 de paclobutrazol, aplicados no estádio 6 ou 8 da escala Feeks e Large, e uma testemunha. O comprimento do colmo com trinexapac-etil foi menor do que com o clormequat, que, por sua vez, foi menor do que com o paclobutrazol. A aplica o de reguladores na época 1 promoveu maior redu o dosentrenós basais, enquanto a aplica o na época 2 proporcionou maior influência no pedúnculo. O aumento das doses de clormequat e trinexapac-etil promoveu redu o do comprimento do colmo e das partes que o formam. O aumento das doses de paclobutrazol promoveu respostas pouco expressivas no colmo e seus componentes. The objective of this work was to evaluate the effect of doses and times of application of three growth regulators on wheat stem elongation. The experiments were conducted in Vi osa, Minas Gerais State, from May to September 2005, in a factorial and hierarchicalrandomized block design with four repetitions and a control treatment. Treatments consisted of 500, 1000 and 1500 g ha-1 of chlormequat; 62.5, 125.0 and 187.5 g ha-1 of trinexapac-ethyl and 40, 80 and 120 g ha-1 of paclobutrazol, applied either at the 6 or 8stage of the Feeks and Large scale, with a control. Stem length with trinexapac-ethyl was smaller than with chlormequat, which was in its turn smaller than with paclobutrazol. Application of growth regulators at stage 1 produced shorter basal internodes, whereas the stage 2 application caused greater reduction in the peduncle. The increase in chlormequat and trinexapac-ethyl doses reduced length of stem and its parts. The increase in paclobutrazol doses had very small effects on wheat growth and its parts.
Efeitos de reguladores de crescimento na elonga??o do colmo de trigo
Espindula, Marcelo Curitiba;Rocha, Valterley Soares;Souza, Leandro Torres de;Souza, Moacil Alves de;Grossi, José Ant?nio Saraiva;
Acta Scientiarum. Agronomy , 2010, DOI: 10.4025/actasciagron.v32i1.94310.4025/actasciagron.v32i1.943
Abstract: the objective of this work was to evaluate the effect of doses and times of application of three growth regulators on wheat stem elongation. the experiments were conducted in vi?osa, minas gerais state, from may to september 2005, in a factorial and hierarchical randomized block design with four repetitions and a control treatment. treatments consisted of 500, 1000 and 1500 g ha-1 of chlormequat; 62.5, 125.0 and 187.5 g ha-1 of trinexapac-ethyl and 40, 80 and 120 g ha-1 of paclobutrazol, applied either at the 6 or 8 stage of the feeks and large scale, with a control. stem length with trinexapac-ethyl was smaller than with chlormequat, which was in its turn smaller than with paclobutrazol. application of growth regulators at stage 1 produced shorter basal internodes, whereas the stage 2 application caused greater reduction in the peduncle. the increase in chlormequat and trinexapac-ethyl doses reduced length of stem and its parts. the increase in paclobutrazol doses had very small effects on wheat growth and its parts.
Doses e formas de aplica??o de nitrogênio no desenvolvimento e produ??o da cultura do trigo
Espindula, Marcelo Curitiba;Rocha, Valterley Soares;Souza, Moacil Alves de;Grossi, José Ant?nio Saraiva;Souza, Leandro Torres de;
Ciência e Agrotecnologia , 2010, DOI: 10.1590/S1413-70542010000600007
Abstract: the objective of this work was to evaluate the effect of doses and methods of nitrogen application on the development and yield of two wheat cultivars. the experiment was conducted in vi?osa-mg, from may to september 2005, and it was arranged in a 2x2x5 factorial, randomized block design with four repetitions. the treatments consisted of the combination of the two wheat cultivars, brs 210 and pioneiro, two nitrogen application methods (total dose applied at seed sowing or 20 kg ha-1 at sowing and the remaining as topdressing in the beginning of tillage) and five n doses (40, 60, 80, 100 and 120 kg ha-1) with ammonium sulfate as n source. cultivar pioneiro showed higher yield potential than cultivar brs 210, but it was less resistance to lodging. splitting nitrogen fertilization increased lodging and brought no benefit to grain yield. grain yield response to n doses was quadratic, reaching maximum at 96.8 kg ha-1, and linear increase in lodging of cultivar pioneiro plants.
Rates of nitrogen and growth retardant trinexapac-ethyl on wheat
Espindula, Marcelo Curitiba;Rocha, Valterley Soares;Souza, Leandro Torres de;Souza, Moacil Alves de;Campanharo, Marcela;Grossi, José Ant?nio Saraiva;
Ciência Rural , 2011, DOI: 10.1590/S0103-84782011001200002
Abstract: the objective in this study was to evaluate the effects of nitrogen rates in association with rates of the growth retardant trinexapac-ethyl on wheat. the experiment was conducted in vi?osa, mg and arranged in a 5×4 factorial, randomized block design, with four repetitions. a combination of five nitrogen rates (30, 60, 90, 120 and 150kg ha-1) with four rates of trinexapac-ethyl (0, 62.5, 125 and 187.5g ha-1) were tested. trinexapac-ethyl promotes reduction of soot dry mass and grain yield at the lowest n rates, but at the highest n rates there is increase in these characteristics. the combination between n and trinexapac-ethyl rates that promotes higher shoot dry mass is 150kg ha-1 and 187g ha-1 but that promotes higher grain yield is 100kg ha-1 and 120g ha-1, respectively.
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