REDUCED HERBICIDE DOSES IN COMBINATION WITH ALLELOPATHIC SORGHUM WATER FOR WEED CONTROL IN SUNFLOWER (Helianthus annuus L.)

A field trial to investigate the response of sunflower and itsweeds to sorghum water extract (Sorgaab) in combination with reduceddoses of herbicide (i.e. Dual gold) was carried out at Agronomic ResearchArea, Faculty of Agriculture, Gomal University, Dera Ismail Khan duringthe year 2007. The experiment was laid out in Randomized CompleteBlock Design (RCBD) with seven treatments and four replications using asub plot size of 2.8m x 4m. Results revealed that Sorgaab @ 15 L ha-1+Dual gold @ 1.6 L ha-1, 1/3 dose reduced Chenopodium album densityby 92% at 70 DAS. Sorgaab alone @ 15 L ha-1, full dose reducedChenopodium album density by 81% at 70 DAS. Sorgaab + Dual gold,1/3 dose reduced Coronopus didymus density by 68%. While Sorgaabalone @ 15 L ha-1, decreased Coronopus didymus density by 36%.Sorgaab + Dual gold, 1/3 dose decreased total weed density by 89%,over control at 70 DAS. While Sorgaab alone @ 15 L ha-1 reduced weeddensity by 76% at 70 DAS. Total dry weed biomass suppressed bySorgaab + Dual gold, 1/3 dose was 92% at 70 DAS. While Sorgaab alone@ 15 L ha-1 reduced total dry weed biomass by 85% at 70 DAS. It wasalso observed during this study that plant height, head diameter, stemdiameter, number of achenes per head, 1000-achene weight and acheneyield were significantly affected by the combination of Sorgaab @15 L ha-1,full dose and Dual gold @ 1.6 ha-1 1/3 dose.