EFFECTS OF WEED-CONTROL AND NITROGEN LEVE LS ON PROTEIN-CONTENT OF CORN GRAINS

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