Differential performance of pinto bean under varying levels of soil moisture

Abstract

Common bean (Phaseolus vulgaris L.) is a relatively new crop in western Canada. Considerable effort is currently underway in Saskatchewan to expand bean production under both irrigated and rainfed conditions. The objectives of this study were to evaluate the performance of pinto bean genotypes under irrigation in the field and to determine the presence of phenological plasticity among specific pinto bean genotypes when subjected to intermittent drought stress. Six bean genotypes, three determinate and three indeterminate, were grown under irrigated conditions in the field in Saskatoon, SK, in 1994 and 1995. The same genotypes were grown under well-watered and drought stress conditions in the growth room. In the field, indeterminate genotypes were superior in seed yield. The indeterminate genotypes were also superior in seed yield in the growth room under well-watered conditions. Two indeterminate genotypes and one late-maturing determinate genotype performed well when drought stress was intermittent, but yielded the same or less than the early-maturing determinate types when drought stress was severe. The indeterminate genotypes and one late-maturing determinate genotype showed stronger recuperative growth than early-maturing determinate genotypes when released from drought stress. Recuperative growth resulted in delayed maturity relative to growth under optimum soil moisture levels, but it had little effect on other characteristics. Key words: Phaseolus vulgaris, common bean, pinto bean, genotype, drought stress