Stability and adaptability analysis of soybean grown in Parana State

Abstract

The stability and adaptability analysis of soybean (Glycine max (L.) Merrill) cultivars in Parana State is important to assure the release of good cultivars. The estimates were obtained from data of the intermediate and final soybean yield trials carried out from 1987 to 1990. Genotypes of three maturity groups, early (L), semi-early (M) and medium (N), were analized. The simple regression and bi-segmented regression methods were jointly used to allow a good classification of the genotypes. Out of the 14 materials assessed, Lancer in group L, OCEPAR-11, M, and FT-2, N, were considered the most stable. Considering the regression coefficient (b) and the yield mean, genotypes FT83-934 and OCEPAR-14 (L), BR85-18565 and OCEPAR-13 (M), and OC87-216 (N) showed medium responsiveness and good adaptation to all the environments. Genotypes FT82-7099 (M), FT-10 and FT-2 (N) were considered moderately adapted and moderately responsive to the improvements made in the environment. OCEPAR-11 was considered highly responsive and medially adapted to unfavorable environments. The simple regression explained satisfactorily the stability and the bi-segmented regression was useful to classify the genotypes in each environment. Under the concepts used in this work, the quality of information obtained by the simultaneous use of both procedures was improved.