Adaptability and stability of soybean in terms of oil and protein content

The objective of this study was to evaluate the influence of genotype x environment interaction on the seed oil and protein content in soybean genotypes (Glycine max L. Merrill). Fifteen soybean genotypes were evaluated. The experiments were conducted in the growing seasons 2004/05, 2005/06 and 2006/07 in Vicosa and Frutal, Minas Gerais (MG), and Pindorama, Sao Paulo (SP), respectively, with different planting dates and soil types, in a total of 13 environments. The evaluation was based on the methods of Eberhart and Russell and Extended Centroid. The results showed that genotype UFV 18 is desirable in soybean breeding programs designed to increase the values of the two traits evaluated. The results of genotype PTN-Bio were different for each trait. Moreover it was noted that the Extended Centroid method is more conservative than the methodology of Eberhart and Russell in the classification of genotypes.