WEEDING STAGES AND THEIR EFFECT ON YIELD AND YIELD COMPONENTS OF RICE IN UPPER SWAT-PAKISTAN

To study the effect of different weeding levels and stages on growth, paddy yield and yield contributing components of coarse rice, a field experiment was conducted at Agricultural Research Institute (ARI-North) Mingora (Swat) Pakistan during kharif season 2013. Experimental design used was Randomized Complete Block Design (RCBD) with four replications. The experiment consisted of seven treatments namely no weeding (T1), one stage weeding (Transplanting to flowering) (T2), one stage weeding (Flowering to panicle setting) (T3), one stage weeding (Panicle setting to maturity) (T4), two stage weeding (Transplanting to flowering and Flowering to panicle setting) (T5), two stage weeding (Flowering to panicle setting and Panicle setting to maturity) (T6), and three stage weeding (Transplanting to flowering, Flowering to panicle setting and Panicle setting to maturity) (T7). Weeds density significantly influenced all the agronomic traits of the rice plant. Minimum weeds per unit area in all growth stages were observed with T6 and T7. It was observed from the results that T6 and T7 reduced weeds population in all the growing period of rice crop. Yield components such as number of tillers were improved and showed best performance (20.84) with T2 on one stage weeding (Transplanting- flowering) that was at par (21.20) with T7 at three stage weeding (transplanting to flowering, flowering to panicle setting and panicle setting to maturity). Three stage weeding (transplanting - flowering, flowering – panicle setting and panicle setting – maturity) make sure that maximum panicle length (21.83cm), highest paddies panicle- (183.7), highest 1000 paddy weight (20.31g) and highest paddy yield (4196 kg ha^-1) was recorded as compared to other weeding stages. Among weeding stages minimum paddies panicle-1(147.25), panicle length (15.67 cm) and 1000 paddies yield (16.32 g) was observed in one stage weeding (transplanting to flowering) followed by one stage weeding (flowering to panicle setting). Lowest tillers, paddies panicle^-1, panicle length, 1000 paddy weight and paddy yield was noted in no weeding. These components highly affected yield and yield contributing parameters of rice.