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

Abstract

ABSTRACT A field experiment was carried out at the Agronomy research field of Sher-e-Bangla Agricultural University, Dhaka, during April to August, 2014 in order to study the efficacy of herbicides to control weeds and its residual activity on growth and yield of transplanted aus rice, (Nerica). The experiment was laid out in a Randomized Complete Block Design (RCBD) with three replications that consisted of 13 treatments viz. T 1 (Propyrisulfuron @ 500 ml ha ), T 2 (Propanil 60 WG @ 2000 g ha -1 ), T 3 (Propyrisulfuron @ 500 ml ha -1 +Propanil 60 WG @ 2000 g ha -1 ), T 4 (Propyrisulfuron @ 500 ml ha -1 +Propanil 60 WG @1500 g ha

(Propyrisulfuron @ 380 ml ha -1 +Propanil 60 WG @ 2000 g ha -1 ), T (Propyrisulfuron @ 500 ml ha -1 +Propanil 60 WG 1000 g ha -1 ), T 7 (Propyrisulfuron @ 250 ml ha 6 -1 +Propanil 60 WG @ 2000 g ha -1 ), T 8 (Propyrisulfuron @ 380 ml ha -1 +Propanil 60 WG @ 1500 g ha

(Propyrisulfuron @ 250 ml ha -1 +Propanil 60 WG @1000 g ha -1 ), T (Propyrisulfuron @ 500 ml ha -1 +Propanil 60 WG @ 667 g ha -1 ), T 11 10 (Propyrisulfuron @ 130 ml ha -1 +Propanil 60 WG @ 2000 g ha -1 ), T 12 (Acetochlor 14 % +Bensulfuron-methene 4% @ 742 g ha

(Weedy check). Nineteen different weed species infested the field among which Marsilea quadrifolia and Cyperus difformis were dominanted throughout the growing period (45.25 % and 48.51 %, 42.24 % and 40.67 %, 47.06 % and 38.91%, 56.04 % and 32.59 %, 56.25 % and 32.45%, 57.83 % and 31.21 % at before 3 days of spray, 7, 14, 21, 28 and 45 days of spray, respectively). Results revealed that treatment T 8 (Propyrisulfuron @ 380 ml ha +Propanil 60 WG @ 1500 g ha -1 ) recorded the lowest weed population after 7, 14, 21, 28 and 45 DASP (days after spraying) while the highest weed population was recorded from the control treatment T 13 . The maximum tiller length (107.3 cm), total number of tillers hill (13.67), effective tillers hill -1 (11.33), total number of grains panicle -1 -1 -1 -1 -1 -1 ), T ), T ) and T -1 (69.0), filled grains panicle

(64.33), 1000 grain weight (24.33 g), grain yield (3.81 t ha -1 ), straw yield (4.25 t ha ) and biological yield (8.06 t ha 1 +Propanil 60 WG @ 1500 g ha -1 ) was recorded from treatment T -1 ) whereas, T 13 8 (Propyrisulfuron @ 380 ml ha (Weedy check) recorded the lowest values in all cases except no. of non-effective tillers hill -1 and no. of sterile grains panicle . Considering rapid and residual activity as well as selectivity which is a common desire of the farmers, it appeared from the above results that treatment T 8 (Propyrisulfuron @ 380 ml ha +Propanil 60 WG @ 1500 g ha -1 ) performed better than other herbicidal treatments. -1 -1 -1 5 9 13 -1 -