A field experiment was carried out during winter seasons of 2002-03 and 2003-04 in Nadia, West Bengal, India to study the effect of chemical methods of weed control in zero-till wheat. The results revealed that the crop was severely infested with sedges and grasses. The pooled analysis showed 50 percent reduction in grain yield due to weed-crop competition. All weed control methods effectively reduced weed density and markedly suppressed dry weight of weeds. Growth parameters of wheat like tiller density, leaf area indices, crop growth rates and yield components (spike density, number of filled grains per spike and test weight of grain) increased significantly by the application of chemicals over weedy control in comparison to others. Application of metribuzin at 175 g ha -1 before first irrigation effectively controlled all categories of weeds in zero-till wheat resulting in 78.2 percent increase in grain production which was comparable with weed free and two manual weedings. Among the chemical control measures, metribuzin 175 g ha -1 before first irrigation was most economical by paying highest net return (Rs. 18 598/-) and benefit-cost ratio (2:1).
