Componentes da produção em cultivares de soja com crescimento determinado e indeterminado

Abstract

The obtain more productive soybean cultivars is increasingly difficult, due to high levels of productivity has already achieved for this legume. The work had as objective to evaluate the components of the production of soybean cultivars of determinate and indeterminate growth, aiming the indirect selection for major productivity of grains. Three cultivars of soybean with type determinate of growth and four with type indeterminate were evaluated, in the agricultural year 2009/2010. The experimental design was randomized blocks with four replications and seven treatments (cultivars). The characteristics analyzed were: plant height, number of nodes per plant, number of pods and grains per plant, grain yield per plant, grain yield components in the last four nodes; thousand grain mass, plant fresh mass; harvest index, number of branches and pods on the branches. We have used analysis of variance in randomized blocks with information within the plot. The differences among average have been compared by Tukey test at 5% probability. The phenotypic variances and covariances obtained by ANOVA generated the phenotypic matrix of correlation among traits. Following has been realized the path analysis. Cultivars with type determinate of growth and indeterminate don’t differ as to the components of production, differ only for height at maturity. But the criterions used for selection should not be the same between the two types of cultivars. The number of pods total and number of pods on branches for cultivars with determinate growth and the harvest index for indeterminate showed the most importance for indirect selection of cultivars more productive. Independent of the type of growth, the number of grains per plant is directly related with the maximum productivity in soybean.