WEED DENSITY AND GRAIN YIELD OF WHEAT AS AFFECTED BY SPATIAL ARRANGEMENTS AND WEEDING TECHNIQUES UNDER RAINFED CONDITIONS OF POTHOWAR

A field trial was conducted at the Experimental Farms of Pir Meher Ali Shah Agriculture University, Rawalpindi during Rabi season, 2004 to study the effect of spatial arrangements and weeding techniques on weeds and yield of wheat. The experiment was laid out in randomized complete block design with two factors under split plot arrangement having three replications. The spatial arrangements were comprised of 15 cm, 22.5 cm and 30 cm apart rows and there were six weeding techniques viz. weeding check was included for comparison, hand weeding (weed free), chemical control (by application of Buctril Super @ 750 ml ha^-1), bar-harrow 2–way, hoe and barharow 1-way. Hand weeding and chemical control with different spatial combinations showed significant effects on weed density, weed mortality percentage, weed biomass and grain yield. Spatial arrangement of 15 cm significantly decreased the weed biomass and enhanced grain yield. The interaction between weeding techniques with spatial arrangements was found significant for weed biomass and grain yield. The highest wheat crop yields of 5448 and 5970 kg ha^-1 were achieved by using hand weeding and chemical control weeding techniques along with 15 cm spatial arrangement. These treatments caused significant increase of 133.93 % and 113.47% respectively over weedy check with 30 cm spacing.