Rita de Cássia Teixeira

Desempenho agronômico de variedades e linhagens de soja em condições de baixa latitude em Teresina-PI

This study had as its objective to evaluate the agronomic performance of soybean varieties and strains grown under low-latitude conditions in Teresina, PI. Phenological traits, yield, and characteristics related to the development of soybean plants from 32 genotypes taken from pre-launch strains and varieties were evaluated, some already launched in states in the midwest region of Brazil. The experimental design used was of randomized blocks with four replications. Under the conditions studied, 13 genotypes (nine varieties and four strains) were identified as having good agronomic performance in low latitudes, with an average grain yield of over 2,900kg ha-1 (48.3 sacks of 60kg ha-1). Of those genotypes studied, based on certification of BRS Sambaiba and Msoy 9350, those that stood out most for the traits assessed and for satisfactory mechanical harvesting under low-latitude conditions, were the Conquista and Valiosa RR varieties and the strains BCR892 G132, BCR651 G75 and BCR6651 G68.

Adaptabilidade e estabilidade de genótipos de soja avaliados para resistência ao oídio

The objective of this research was to identify soybean genotypes with good adaptability and stability of behavior for resistance to powdery mildew in field conditions. The work was carried out at the Professor Diogo Alves de Mello Experimental Station, Agronomy Department of the Federal University of Vicosa (UFV), Vicosa, Minas Gerais. The experiment was arranged in a randomized block design, in split-plots, with 15 genotypes (plots) and seven evaluation times (subplots), with four repetitions. Evaluation of incidence and severity of powdery mildew in the genotypes were accomplished by visual quantification of fungus infection level (IL), assessing the level of infection of the leaf area infected (NIAFI) by the powdery mildew and the level of infection of the most infected leaflet (NIFI). Data were examined by analysis of variance and analysis of adaptability and stability according to EBERHART & RUSSELL (1966). The results allowed to get to the following conclusions: the genotypes that showed the highest resistance levels, were, in general, also the ones of higher adaptability and stability, both for NIAFI and NIFI, standing out UFV 89-361826 T2, UFV 94-334268, UFV-16 and UFV-19, FT-10 RC5 (F3), FT-Abyara RC6 (F2), Doko RC, FT-Abyara RC5 (F4), whereas the most susceptible genotypes were the ones of worse predictability, standing out UFV 94-5126, FT-104, UFV 94-3500, FT-Cristalina, FT-Estrela and BR-16.

Adaptabilidade e estabilidade de genotipos de soja avaliados no Estado do Mato Grosso

Este trabalho teve o objetivo de avaliar o desempenho, a estabilidade e a adaptabilidade de 20 genotipos de soja [Glycine max (L.) Merrill], em seis ambientes no Estado do Mato Grosso. O delineamento experimental foi blocos ao acaso, com tres repeticoes. Os ensaios foram conduzidos nos anos agricolas de 2004/05 e 2005/06 nos municipios de Rondonopolis, Campo Verde e Vera. Para avaliacao da adaptabilidade e estabilidade, utilizaram-se os metodos de Lin & Binns (1988) modificado por Carneiro (1998) e Centroide (Rocha et al., 2005). A produtividade media de graos variou de 2.372 kg.ha-1 (Rondonopolis IV) a 3.539 kg.ha-1 (Vera), com media geral dos ambientes de 2.994 kg.ha-1. Em ambas as metodologias, as linhagens BCR 02 57, BCR 02 25, e BCR 02 20 e os cultivares Tabarana e SL 88102 foram classificados como os mais produtivos, adaptados e estaveis, havendo, portanto, coerencia entre tais metodologias. Foram recomendadas as linhagens de soja BCR 02 57, e BCR 02 25, BCR 02 20 para amplas condicoes ambientais, tendo em vista a produtividade de graos superior.

Correção do efeito ambiental em ensaios de famílias de soja, intercaladas com testemunhas, para predição de ganhos por seleção

One F5 soybean population was evaluated in Vicosa-MG, Brazil, during the 1997/98 growing season. The experimental design was of families without replications, inserted with controls, with replications, allowing the estimation of the environmental component associated to the phenotypic variance of the population under study, and consequently the genetic parameters. The evaluations at family and at individual within the family allowed to decompose the genotypic variance and to estimate the heritability on the narrow sense. The environmental effect correction was based on the replications of controls. The correction of the environment effect favored the selection of the families that originally showed performance a little inferior to the original selection truncation point, but were not favorable by the environmental, causing changes in the family groups selected through the simulation of the same selection strategies on the original and corrected data.