Abstract

This study aims to identify the phenotypic effects of traits associated with soybean pods and their growth habit. The experiments were carried out during the 2012 - 2013 agricultural year. It was done in randomized blocks arranged in a 2×20 factorial design (environments × soybean cultivars) with three replications. Data were subjected to individual analysis of variance for each environment and growth habit to verify the homogeneity of variances. Phenotypic path analysis among agronomic traits was performed for each environment within the soybean growth habits. The results showed considerable influences of growth habit via traits associated with soybean pods. The traits number of pods with two, three, and four grains directly influenced the grain yield of genotypes with indeterminate growth habit regardless of the environment. The soybean genotypes with determinate growth habit contributed greatly to grain yield through the traits number of pods with one, two, and three grains and thousand grain weight via pods with two or four grains. Indirect selection of superior genotypes for pods per plant and grain weight could provide satisfactory results for soybean yield in relation to the growth habit. The interrelationships obtained between growth habits and environments, can be applied to superior genotypes selection strategies in breeding soybean programs.

Key words: Agriculture science, biometric models, Glycine max L., indirect selection, grain yield, soybean breeding.