IMPACT OF PHYSICAL AND CHEMICAL WEED CONTROL ON WHEAT YIELD AND YIELD COMPONENTS

Field experiment was conducted at Research Farm, Faculty ofAgriculture, Gomal University, Dera Ismail Khan, Pakistan duringRabi 2007-08 to study the effect of herbicides and tillage onweeds and wheat. The experiment was carried out inrandomized complete block design with split plot arrangementreplicated four times. The treatments included in the experimentwere 3 tillage depths viz. shallow tillage (5-7.5 cm with onecultivator and rotavator), medium tillage (10 cm with 2 cultivatorand rotavator), and deep tillage (20-25 cm with disk plough,cultivator and rotavator) assigned to main plots, while five weedcontrol treatments i.e. 2,4-D amine @ 1 L ha-1, Topik 15 WP @0.09 kg a.i ha-1, 2,4-D + Topik (clodinafop), hand weeding thrice(at 20, 35 and 50 days after sowing) and untreated weedy check(control) were assigned to subplots. Data were recorded onweed density m-2, fertile tillers m-2, spike length (cm), grainsspike-1, 1000 grains weight (g) and grain yield (t ha-1). Tillageand herbicides significantly affected yield and yield componentsof wheat. Deep tillage produced highest yield and yieldcomponents followed by medium tillage and shallow tillage.Hand weeding performed better regarding yield and yieldcomponents closely followed by 2,4-D + Topik. Deep tillage incombination with either hand weeding or mixture of 2,4-D +Topik is recommended for effective weed management andenhanced grain yield of wheat.