STUDIES ON CRITICAL STAGE OF CROP WEED COMPETITION IN MAIZE

A field experiment was conducted during wet seasons of 1983 and 1984 at ICAR Research Complex for NEH region, Shillong to study the critical stages of crop weed competition in maize. First 20-40 days after sowing were most critical for weed removal in maize. Weed removal 40 DAS removed monocot and dicot weeds to almost 50% and reduced weed dry matter yield to 43 and 57%, respectively in comparison to weedy check. Keeping the fields weedy up to 40 DAS reduced grain yield by 43.8%. Weed removal 40 DAS saved N, P, K removal by 39.4, 0.9, 22.5, and 110.0, 5.3, 100.4 kg/ha through monocot and dicot weeds, respectively.