Rendimiento y calidad de semilla de frijol en dos épocas de siembra en la región del Bajío

the lack of high quality seed of improved cultivars at an affordable price to farmers is one of the main constraints for common bean production in mexico. the aim of this research was to determine the yield and seed quality in eight bean cultivars of four different commercial classes produced in two growing seasons. the field trial was established during 2006 at the bajío experimental station in the winter-spring season in march 5th under irrigated conditions and in the summer season in july 5th under rainfall conditions. the genotypes utilized were: flor de junio marcela and fj07001, flor de mayo anita and flor de mayo noura, pinto durango and pinto saltillo, azufrado 26 and azufrado noroeste. sowing was on moist soil and the experimental plot consisted of three 5 m rows separated at 0.8 m and a stand of 20 seeds m2. traits recorded in the field were of the agronomic type whereas in the laboratory the percentage and germination rate were recorded with and without exposing the seed to the accelerated aging test. in both planting seasons, flor de mayo cultivars were the top yielders along with flor de junio cultivars in the irrigated trial and with pinto saltillo in the rainfall trial. in both trials the cultivars of the azufrado type showed the lower yields. azufrado noroeste showed the lowest percentage of standard germination (89%) in the seed from the irrigated trial. with the accelerated aging test the seed of pinto saltillo from both trials lost germination capacity from 93 and 95% to 72 and 67%, respectively, while the one from azufrado noroeste and pinto durango from the rainfed trial had a germination capacity of 48 and 59%, respectively. flor de mayo and flor de junio cultivars showed an average germination of 80% after the accelerated aging treatment. in general, germination was more affected in the seed from the rainfed trial, particularly the pinto and azufrado cultivars. these results were attributed to the presence of diseases in the rainfall trial and