Abstract
To investigate the effect of planting densities (i.e. 12, 9, 6 and 3 plants m-2 ) of maize cv. Azam on suppression of barnyard grass, a field trial was undertaken at New Developmental Research Farm, the University of Agriculture, Peshawar, Pakistan from June-October 2006. The trial was laid out in a randomized complete block design with four replications. Growth parameters such as plant height, leaf area, and specific leaf area plant-1 and shoot dry biomass were recorded both for maize and barnyard grass while grains cob-1 , 1000 grains mass and grain yield was recorded only for maize. Different planting densities of maize had showed significant effects upon various growth parameters of barnyard grass and maize crop. Overall, the higher planting densities have shown better suppression of barnyard grass growth but at the highest planting density (12 maize plants m-2 ), the crop suffered its yield possibly due to intra-specific competition between the crop plants. The moderately high density (9 maize plants m-2 ) produced best results in this study. Therefore, it can be recommended that 9 maize plants m-2 may be planted for better suppression of barnyard grass and harvesting higher yields of maize.
