Growth And Development Of Indeterminate Bush And Climbing Cultivars of Phaseolus vulgaris L. Inoculated with Rhizobium

Abstract

SUMMARY: Twenty cultivars of P. vulgaris differing in growth habit, and inoculated with an efficient strain of R. phaseoli, were sampled weekly in the period 22—99 days after planting. Acetylene reduction and specific nodule activity were similar to or better than those reported for other grain legumes, and were higher than achieved by a soya-bean cultivar. Though the period of active fixation was limited, nitrogen gains estimated at 25—30 kg/ha/growing cycle were obtained. Climbing beans were superior to bush beans in acetylene reduction and specific nodule activity, but differed little in nodule development. Two varieties, Cargamanto and Sangretoro, were outstanding in fixation. Differences between varieties in nodule to root ratio, and in rate of N accumulation in the leaves were shown. Both groups of plants stored appreciable starch in the stem after flowering. The results are related to the need for N fertilization in Latin America.