Genotype by environment interaction for disease resistance and other important agronomic traits supporting the indication of common bean cultivars

The present work aimed to study the genotype by environment interaction for nine important agronomic traits as a support for the indication of common bean cultivars for the Southern region of Brazil, identifying cultivars that possess high adaptability/stability. We carried out 25 field trials, in the rainy and dry sowing seasons, at different locals in the states of Parana and Santa Catarina, from 2008 to 2010. The trials included 17 cultivars. Data were obtained for agronomic traits and subjected to variance analyses, and to adaptability and stability analyses according to the Nunes method. The genotype by environment interaction is important for different agronomic traits. There is genetic variation among cultivars and it was identified a different number of superior cultivars for each trait. Considering the means and adaptability and stability scores, 88% of the cultivars were superior for rust, 53% for anthracnose, 41% for grain yield, plant architecture and cycle, 30% for fusarium wilt and lodging, and 18% for angular leaf spot and common bacterial blight. For some of these traits, like angular leaf spot, common bacterial blight, fusarium wilt and lodging, it is necessary to intensify the efforts to provide more cultivars with high resistance or tolerance level, adaptability and stability. BRS Esplendor, a black-seeded cultivar, CNFC 10431 and BRS Sublime, both carioca-seeded cultivars, presented superiority for six of nine traits, being indicated to be used in the Southern region of Brazil. Other cultivars presented advantages for fewer traits and must be used in environments which these traits present greater importance.