COMMON BEAN GRAIN YIELD AND QUALITY AS AFFECTED BY NITROGEN SIDEDRESSING AND LEAF APPLICATION

COMMON BEAN GRAIN YIELD AND QUALITY AS AFFECTED BY NITROGEN SIDEDRESSING AND LEAF APPLICATION Appropriate nitrogen availability during the common bean cycle is essential to ensure high grain yield and quality. This nutrient can be absorbed by the roots and leaves. However, there are still doubts about the efficiency of N leaf application and the influence on common bean grain quality. Therefore, the purpose of this study was to evaluate the effect of N sidedressing and leaf application on common bean grain yield and quality. The experiment was carried out in the dry growing season, on a Haplorthox, in Botucatu, Sao Paulo State, Brazil. The experiment was arranged in a randomized block design with four replications, in a 3 x 4 factorial scheme consisting of three N sidedressing rates (0, 45, and 90 kg ha(-1)) and four times of N application (1 - control without leaf spraying, 2 - N leaf spraying in the pre-flowering stage (R5), 3- N leaf spraying in the beginning of pod formation (R7), and 4 - N leaf spraying in R5 and R7). For each N leaf spraying, 200 L ha(-1) of a solution containing 10 % of urea was used. When N sidedressing was applied, N leaf application, regardless of the time, did not affect the common bean yield components, grain yield and quality. In absence of N sidedressing, N leaf spraying in the reproductive phase of common bean plants increased grain weight and size, grain yield, and protein concentration. N leaf spraying in R5 increased common bean grain yield more than leaf spraying in R7.