EFFECT OF HERBIGATION ON WEED DYNAMICS AND YIELD IN DIRECT SOWN AEROBIC RICE (Oryza sativa L.)

Abstract

A Field experiment was conducted at Annamalai University experimental farm during the season Summer, 2020. to find out the effect of herbigation based weed management practices in direct sown aerobic rice on weed and yield parameters. The experiment was laid out in a randomized block design with eight treatments and replicated thrice. The results showed that among the  different herbigation treatments, PE herbigation of pretilachlor + bensulfuron methyl 660 g ha^-1 on 3 DAS fb PoE herbigation of bispyribac sodium 25 g ha^-1 on 20 DAS recorded lower weed density Table 1. (23.70 m^-2 and 33.52 m^-2) less dry weight of weeds (39.3 kg ha^-1 and 65.10 kg ha^-1) which exhibited highest WCE (87.65 and 89 %) than other treatments on 20 and 40 DAS. whereas, weed free check stood superior in all the  aspects of crop and weed parameters except in monetary returns. Suppression of weeds among the treatments resulted in weed free plot to record higher grain yield. PE herbigation of pretilachlor + bensulfuron methyl 660 g ha^-1 on 3 DAS fb PoE                         herbigation of bispyribac sodium25 g ha^-1 on 20 DAS recorded highest grain yield of (6156 kg ha^-1) and lowest weed index of (2.56 %) and it was on par with PE herbigation of pretilachlor + bensulfuron methyl 660 g ha^-1 on 3 DAS fb HW on 30 DAS (6107 kg ha^-1) which was significantly superior to other treatments. Weedy check had accounted for lower yield of (3500 kg ha^-1) and highest weed index (44.60 %) due to heavy weed infestation.