Response of snap bean cultivars of determined growing to inoculation with Rhizobium tropici

Abstract

The biological nitrogen fixation is a process biological performed by legumes, through symbiotic with bacteria. However, in crop of snap bean, the process is not efficient, wherein some efficient cultivars may be responsible for inoculation. The objective was to evaluate the behavior of seven cultivar bean cultivars determined growing in relation to the inoculation with Rhizobium tropici. The experiment was carried out in the DIC, with four replicates, in the factorial 7x2, corresponding to seven cultivars of bean-pod of determined growth (Commodore Improved, Contender, Delinel, Jade, Strike, Stringless Green and Provider), in the presence and absence of rhizobian inoculum (R. tropici). The height, diameter, number of leaves, leaf area, dry mass of the aerial part were evaluated at the flowering stage; length, area, root dry mass; the number of nodules; nitrogen content, accumulated nitrogen, nitrogen utilization efficiency, specific nodulation, and relative efficiency. The use of R. tropici does not interfere in the vegetative development of the aerial part of the bean pod until the flowering phase. The cultivars Delinel, Jade and Stringless Green stand out when nodulation. The inoculation negatively affects the nitrogen and nitrogen contents accumulated by the aerial part, but it is able to increase the number of nodules, specific nodulation and the efficiency of nitrogen utilization. There is a negative correlation between the nodulation and the dry mass of the aerial part, nitrogen content and the nitrogen accumulated by the aerial part.

Keywords

• phaseolus vulgaris. biological nitrogen fixation. rhizobia. nodulation. nitrogen utilization efficiency.