Productivity and gas exchanges of the common bean subjected to inoculation and nitrogen fertilization

Abstract

Beans are one of the main foods consumed in Brazil. It is considered an essential ingredient in the basic diet of Brazilians. As a management practice, aiming to supply N and increase crop productivity, producers have used the association of seed inoculation with nitrogen fertilization. Thus, the objective of this study is to evaluate the effects of split nitrogen fertilization and seed inoculation on common bean productivity. The experiment was carried out in completely randomized blocks and a 2x2x3 factorial design with four replications. The first factor was seed inoculation (presence or absence) with peat inoculant containing the strains SEMIA 4077 and SEMIA 4080 from R. tropici and the strain SEMIA 4088 from R. freirei. The second factor was the parceling of nitrogen cover fertilization (80+40 and 60+60 kg ha-1 of N at 20 and 40 days after emergence (DAE)). The third factor was time of assessment (50, 65 and 80 DAE). The inoculated bean showed a 5% higher leaf N content than non-inoculated ones. Transpiration and liquid photosynthesis rates were higher in inoculated plants and in those with 60+60 kg ha-1 of N. However, productivity was 13% higher in uninoculated beans regardless of nitrogen fertilization.