Response of Determinate and Indeterminate Common Bean Genotypes to Rhizobium Inoculant in a Short Season Rainfed Production System in the Canadian Prairie

ABSTRACT

Common bean (Phaseolus vulgaris L.) has been shown to be a poor di-nitrogen (N₂) fixer and nitrogen (N) fertilizers are usually recommended in bean production. Recent research results suggest that the success of the bean/Rhizobium symbiosis may depend, in part, on the specific bean genotype. Twelve dry bean genotypes differing in growth habit, commercial class, and maturity were evaluated for N₂ fixation in field experiments. Response to inoculant application was highly influenced by environmental conditions. Genotypes differed in nodule dry mass, seed yield, seed N yield, and in amount of N₂ fixed. Growth habit alone was not adequate in classifying bean genotypes for N₂ fixation. The actual amount of N₂ fixed was low ranging from 16 kg ha^?1 to 27 kg ha^?1, suggesting that the symbiotic process alone may not provide adequate N for optimum seed yield in dry environments.