The performance of bean lines brought forth in breeding programs or of cultivars in use can be affected by environmental variability. The adaptability and stability of grain yield of 18 common bean cultivars and lines in 23 environments (combinations of seasons, years and locations) were evaluated in the State of São Paulo, Brazil. 'IAC-Carioca' and 'IAC-Carioca Eté' were used as standard cultivars for the carioca grain type, while 'FT-Nobre' and 'IAC-Una' represented the standard for black grains. The experiment was set up in a randomized complete block design with four replications and plots consisting of two, two central five meters rows flanked by border rows. Stability parameters were estimated by the methods Maximum Yield Deviations (MYD) and by the Additive Main Effects and Multiplicative Interaction Analysis (AMMI). For the identification of the most stable cultivars, the two methods led to consistent results, although by MYD the highest stability was always associated to the highest yield. 'MAC-733327' and 'LP 9637' were the most suitable cultivars and lines for the joint seasons, while 'LP 9637' and 'FT-Nobre' were the most suitable for the dry season. The MYD method combined a simple procedure, easiness of result interpretation, uniqueness of parameters, and association between stability and yield. On the other hand, the AMMI method simplified the identification of stable cultivars by visual inspection, also providing information on the environments. However, the complex nature which combines uni-and multivariate techniques hampers its widespread use in breeding programs.
Phaseolus vulgaris; AMMI; adaptability; stability; cultivar