Ontogeny of nodulation in lima-bean (<i>Phaseolus lunatus</i>)

Abstract

The lima-bean, Phaseolus lunatus L., is the second most important legumes plant of Phaseolus genus, having the capacity of, symbiotically with rhizobia, to nodule and fix N₂. The aim of this paper was to determine ontogeny of nodulation in lima-bean (Phaseolus lunatus) cultivated in two soil types of mid north region. The experiment was conduced in a greenhouse using genotypes “UFPI-491” and “UFPI-468” cultivated in two soil types. The evaluations were made to the 30, 45, 60 and 75 days after plants emergence, being measured nodule number, dry mass and size. There was significative effect (P < 0.05) to periods of evaluations on all variables. The genotypes and soils showed similar behavior related to nodulation. The period of higher nodulation in lima-bean occurs in flowering stage between 45 and 60 days after plants emergence.