Response of cultivars of race durango to continual dry bean versus rotational production systems
Continual dry bean (CB, Phaseolus vulgaris L.) production in the same field for 2 or more consecutive years is common worldwide. However, the effects on and performance of dry bean cultivars in the CB production system is not known. The objectives of this research were to (i) determine effects of the CB production system on seed yield, seed weight, and days to maturity of race Durango cultivars; (ii) determine the correlations for those three traits between the CB and rotational production (RP) systems; and (iii) identify superior cultivars within and across both production systems. Medium-sized (25–40 g 100 seed–1) cultivars of great northern (8), pink (3), pinto (9), and red (5) of race Durango released between 1932 and 1998 were evaluated from 1999 to 2001 in a field that had been under 50 yr of CB production at the University of Idaho, Kimberly Research and Extension Center. Concurrently, they were evaluated under the standard RP system. The cultivar effects and cultivar x year interaction effects were significant (P < 0.01) for seed yield, seed weight, and days to maturity in both production systems. Continual dry bean production reduced mean seed yield by 68%, seed weight by 11%, and days to maturity by 6 d. Large differences among cultivars existed within and between market classes in both production systems. On average, great northern and pinto cultivars had the greatest reduction (71%) and pink (56%) followed by red (66%) cultivars had the least reduction in seed yield due to CB production. Cultivars UI 537, UI 239, Viva, and Harold had the highest levels of resistance to CB production. Despite significant (P < 0.01) positive phenotypic correlation between the two production systems for seed yield (r2 = 0.70), seed weight (r2 = 0.90), and days to maturity (r2 = 0.67), testing of dry bean cultivars using both production systems is suggested for identification of superior cultivars to be grown either within or across production systems.