Adubação nitrogenada afeta a produtividade e a qualidade comercial de grãos do feijoeiro em sistema plantio direto

Abstract

The objective of this research was to determine the effect of rates and times of N application on yield parameters and commercial quality of common bean quality cultivars. It was performed two experiments under field conditions. In the first, for each cultivar (BRS FC104 and BRS Estilo), was used the 2 x 7 factorial scheme. The treatments were composed of two N application times (sowing and topdressing) with seven N doses (0, 25, 50, 75, 100, 125 and 150 kg ha-1). In the second, for the same cultivars, we had five treatments (100 kg ha-1 of N at sowing and 0 kg ha-1 in topdressing, 75 kg ha-1 of N at sowing and 25 kg ha-1 in topdressing, 50 kg ha-1 of N at sowing and 50 kg ha-1 in topdressing, 25 kg ha-1 of N at sowing and 75 kg ha-1 in topdressing, and 0 kg ha-1 of N at sowing and 100 kg ha-1 in topdressing). Increasing doses of N provide increases in the number of pods per plant and in grain yield of cultivar BRS FC 104 when applied at sowing or topdressing and provides increases in the number of pods per plant and in grain yield of cultivar BRS Estilo when applied all in topdressing, and provides increases in the commercial quality of common bean grains of cultivars BRS Estilo and BRS FC 104. The application of 100 kg ha-1 of N in topdressing provides a greater mass of 100 grams, grain yield and commercial quality of the grains of cultivars BRS FC 104 and BRS Estilo.