EVALUATION OF HERBICIDAL EFFICACY AND RESIDUAL ACTIVITY ON TRANSPLANTED AROMATIC BORO RICE

Abstract

A field experiment was conducted at the Agronomy research field of Sher-eBangla Agricultural University,

Dhaka during the period from December 2014 to May 2015 to find out the herbicidal efficacy and residual activity on transplanted aromatic boro rice (cv. BRRI Dhan50). This was a single factor experiment which consisted of nine treatments, viz., T 0 : (control), T : Acetochlor + Bensulfuron- methyl (changer) [750 g ha -1 ], T : Pyrazosulfuronethyl (super powder) 150 g ha -1 . T 3 2 1 , T 4 : Pretilachlor (superhit) 1 L ha : Bispyribac sodium (extra power) 150 g ha -1 . T : Pretilachlor + Triasulfuron (Rifit + logran) 1 L ha -1 + 10 g ha -1 , T 6 5 : Propyrisulfuran+ Propanil [500 ml ha +1000 g ha -1 ], T 7 : Propyrisulfuran + Propanil [380 ml ha -1 +1500 g ha -1 ], T : Two hand weeding at 20 DAT and 40 DAT. The experiment was laid out in Randomized Complete Block Design (RCBD) with three replications. T treatment had killed the highest number of weeds its residual activity remained up to 45 days. So, the highest weed control efficacy (98.74%) was found from T 7 treatment and it had checked seven weed species including the dominating weed Behua (Cyperus difformis) from rice field. On the other hand, the highest weed infestation and yield loss (44.09%) were recorded in T (control) treatment. At the later growth stage, the highest plant height, panicle length, maximum number of tillers hill -1 , number of effective tillers hill 0 -1 , minimum non- effective tillers hill -1 , primary branch panicle -1 8 -1 7 , secondary branch panicle , filled grains panicle -1 , minimum unfilled grains panicle -1 , maximum total grains panicle -1 , 1000 grain weight, straw yield (7.11 t ha -1 ), and the highest grain yield (6.35 t ha -1 ) were obtained from T (Propyrisulfuran + Propanil [380 ml ha -1 + 1500 g ha -1 7 ]) treatment compared to the T (control) treatment. It can be concluded that weed free condition throughout the growth period might be considered as an important factor for the best performance of transplanted aromatic boro rice (cv. BRRI dhan50).

0 1 -1