EFFICACY AND RESIDUAL ACTIVITY OF HERBICIDE ON GROWTH AND YIELD OF BROADCAST AUS RICE

Abstract

An experiment was conducted at the Agronomy research field of Sher-e-Bangla Agricultural University, Dhaka, from April to August 2015 to evaluate the different herbicidal efficacy and residual activity on weed control and growth & yield of aus rice cv. BRRI dhan48.There were ten treatments viz. T 1 : Propyrisulfuran@ 500 ml ha : Propyrisulfuran @ 750 ml ha -1 , T 3 : Propanil@ 3750 ml ha -1 , T : Propyrisulfuran+ Propanil @ (500ml+3750g) ha -1 , T 5 4 : Propyrisulfuran + Propanil @ (500 ml + 2500 g) ha -1 ,

T 6 : Propyrisulfuran + Propanil @ (750ml + 3750g) ha -1 , T : Propyrisulfuran + Propanil@ (750ml + 3125g) ha -1 , T 8 7 : Propyrisulfuran + Propanil (750ml + 2500g) ha , T 9 : Bispyribac Sodium @150 g ha -1 and T : Weedy check ( Control). The experiment was laid out in Randomized Complete Block Design (RCBD) with three replications. Sixteen weed species belongs to nine families were observed in the experimental field. Weed population, weed dry weight and weed control efficiency were significantly influenced by different herbicidal treatments. Among the herbicidal treatments, Propyrisulfuran + Propanil (750 ml + 3125 g) ha 10 -1 was most effective with the lowest weed population, weed dry weight and the highest weed control efficiency compared to other treatments. Application of Propyrisulfuran + Propanil (750ml + 3125g) ha showed the best performance to control all kind of weeds and its residual activity remained upto 45 days.Yield and yield contributing characters (total number of tillers hill , number of effective tillers hill -1 , panicle length , number of primary branch panicle , number of secondary branch panicle -1 , total number of grains panicle -1 , number of filled grains panicle -1 ,1000-grain weight and grain yield ) were also influenced significantly by the herbicidal treatments. The highest grain yield (3.75tha -1 ) and harvest index (44.23%) were obtained from the application of Propyrisulfuran +Propanil (500ml +3125g) ha .The lowest yield (1.80 tha -1 ) and harvest index (37.89%) were obtained from the control plot. It can be concluded that application of Propyrisulfuran + Propanil (500ml +3125g) ha

-1 may be an alternative to effective weed control of broadcast aus rice (BRRI dhan48).