Protein contents in common bean grains in different nitrogen sidedressing times and rates - DOI: 10.4025/actasciagron.v27i3.1409

Abstract

Common bean needs high amounts of nitrogen and its grains are important protein source for Brazilian people. This study aimed to evaluate the effects of 2 nitrogen sidedressing doses application, in 8 application phases, on common bean crop, and the protein content and yield (crude and soluble) in grains produced during the winter of 2003 in Selvíria, State of Mato Grosso do Sul, Brazil. A completely randomized design was used with four replications. Treatments resulted of a factorial combination of N rates: 40 and 80 kg ha^-1 applied at sidedressing in eight times of vegetative growth. The crude protein contents were 20.1% and 21.4% for 40 and 80 kg.ha^-1 of N, respectively, whereas soluble protein rates were 14.4% and 16.3%. The application of 80 kg ha^-1 of N promoted yield of 419.4 and 316.3 kg ha^-1 of crude and soluble protein, respectively, representing an increase of 6.0% and 12.4% in comparison to 40 kg ha^-1 of N. Increase in grains’ protein content occurred with N rate increasing to sidedressing. The application of 40 kg ha^-1 N promoted higher increase of crude protein in grains when N application occurred in later stages.