Appropriate management practices and higher nitrogen doses have led to substantial increases in grain yield of common bean, however in winter crop and under irrigated conditions few studies report the interference of nitrogen doses at seeding and in topdressing on the grain production. The study aimed to evaluate the effect of adding increasing doses of nitrogen at sowing and topdressing on the agronomic characteristics of bean irrigated during winter in the northern part of Minas Gerais state. For this purpose a 4 x 4 factorial design was used consisting of four identical doses of nitrogen at sowing and topdressing (0, 40, 80 and 120 kg ha-1). The following characteristics were evaluated: initial stand, final stand, number of grains per pod, pods per plant, mean weight of 100 grains and grain yield. No significant effect (p > 0.05) was obtained between N rates at seeding and/or topdressing for the number of grains per pod and weight of 100 grains. Considering only the addition of N at sowing, the number of pods per plant and grain yield increased with increasing dose up to 120 kg ha-1 N. Despite the interdependence of N rates in seeding and topdressing, major increases in grain yield were obtained with the addition of N at sowing.
common bean; production components; grain yield
