Effects of weed control and nitrogen levels on protein content of corn grains

Abstract

A study was carried out in 1990/91 in Mossoró, RN, Brazil, to evaluate the effects of weed control (no hoeing and hoeing at 20, 40, and 20 and 40 days after sowing) and N levels (0, 60 and 120 kg/ha) on protein content of corn grains of the Centralmex cultivar. The experimental design followed a factorial arrangement in randomized blocks with five replications, and the plants were grown under sprinkler irrigation conditions. Significant effect for weed control and N levels was observed, but not for weed control x N levels interaction. The protein content of corn obtained with no hoeing (8,3%) was lower than those obtained with one hoeing at 40 days (9,7%) or with two hoeings (9,6%), but did not differ from that produced with one hoeing at 20 days (9,1%). The application of 120 kg of N/ha resulted in higher protein content (9,6%) than that found in the absence of N (8,3%). There was no significant difference between zero and 60 kg de N (9,3%) levels.