Fig. 1. GGE (A) and AMMI2 (B) biplots of the first and second principal components for oil yield of 10 sunflower hybrids grown in 46 trials. Genotypes are represented by points and environments by vectors. Black and open circles identify central- and northern-type environments, respectively. In B, symbols indicate genotype groups with members of a similar response pattern at the 4-group level for oil yield. See Table 2 for environment codes.