Yield stability of dry bean genotypes in Honduras

Abstract

Bean (Phaseolus vulgaris L.) cultivars are grown under diverse environmental conditions in Central America because of geography, multiple growing seasons and variable inputs. The regression of mean genotype yields onto mean environment yields may provide useful information for selecting beans with greater yield stability when grown under these conditions. The principal objective of this research was to test yield stability of bean cultivars and promising breeding lines across a range of environments representative of the bean growing regions of Honduras. In 1984, 25 cultivars/breeding lines of various origins were grown in 23 field trials in Honduras. The trials were conducted during two seasons and in three different departments. Stability was examined on the basis of mean square deviations (MSD) from regression, large rank order changes among mean seed yield of genotypes were evident when different seasons and departments were compared. A highly significant correlation of the regression slope (b) with mean genotype yield supported use of MSD to assess yield stability. Mean yield and MSD were not correlated. The two determinate cultivars in the trial had poor stability characteristics. Honduran varieties had greater yield and better stability characteristics than most entries in the trial. Black-seeded lines 'B-190', '3B-5-1' and '8325-7' had high mean yield and good stability characteristics. These results show the importance of testing for yield stability if a cultivar is to be released for use in different regions and seasons in Central American countries. Also high yield and stability, judged on the basis of MSD, can occur in the same genotype.