Yield stability in common bean (Phaseolus vulgaris L.) genotypes

An experiment was undertaken to determine the stability of seed yield in 21 common bean genotypes representing three growth habits. Seven genotypes in each growth habit ( determinate bush, indeterminate bush and indeterminate prostrate) were evaluated in replicated trials at three locations for three years under rainfed conditions in Ethiopia. A combined analysis of variance, stability statistics and rank correlations among stability statistics and yield-stability statistic were determined. The genotypes differed significantly for seed yield and genotype x environment ( year by location) interaction (GE). The different stability statistics namely Type 1, Type 2 and Type 3 measured the different aspects of stability. This was substantiated by rank correlation coefficient. There were strong rank correlations among S(i)(2)d, W-i(2), sigma(i)(2) and S-i(2), whereas there was weak correlation between b(i) and R-i(2), S(i)(2)d, W-i(2), sigma(i)(2) and S-i(2). R-2 was significantly and negatively correlated with W-i(2), sigma(i)(2) and S-i(2). sigma(i)(2) is significantly correlated with W-i(2). Yield is significantly correlated with b(i) and R-i(2). None of the statistics per se was useful for selecting high yielding and stable genotypes except the YS (yield-stability statistic). Most of the high yielding genotypes were relatively stable. Of the 21 genotypes, only 11 genotypes were selected for their high yielding and stable performance. Genotypes with growth habit III and I ( indeterminate prostrate and determinate bush) were generally more stable than indeterminate bush.