Assessment of ready-mix herbicides on weeds and yield of drip-irrigated aerobic rice (<i>Oryza sativa</i> L.) var. CO 51

The present study aimed to check the efficacy of different herbicides on weed management in aerobic rice (Oryza sativa L.) var. CO 51. A field study was conducted at the College Farm of SRM College of Agricultural Sciences, SRM Institute Science and Technology, Chengalpattu, Tamil Nadu during summer, 2024. The trial was exercised using randomized block design with eight treatment combinations and replicated thrice. The treatments consists of T1: Pendimethalin at 1000g ai/ha on 3 DAS (PE) fb hand weeding on 40 DAS, T2:Bensulfuron methyl + pretilachlor at 660g ai/ha on 3 DAS (PE) fb hand weeding on 40 DAS, T3:Bensulfuron methyl + pretilachlor at 660g ai/ha on 3 DAS (PE) fb bispyribac sodium at 25g ai/ha on 25 DAS (PoE), T4:Triafamone + ethoxysulfuron at 67.5g ai/ha on 10 DAS (EPoE) fb hand weeding on 40 DAS, T5:Triafamone + ethoxysulfuron at 67.5g ai/ha on 10 DAS (EPoE) fb bispyribac sodium at 25g ai/ha on 25 DAS (PoE), T6: Bispyribac sodium at 25g ai/ha on 25 DAS (PoE), T7: Hand weeding twice at 20 and 40 DAS, T8:Weedy check. Superior control over weeds and increased grain yield were observed in manual weeding two times at 20 and 40 days after sowing (T7). Among the herbicide treatment combinations, T4 exhibited the best performance in reducing weed density (12.5 No./m2), weed intensity (20.1 per cent), dry weight (11.29 g/m2), and weed index (2.68 per cent) to the lowest levels while higher weed control efficiency (93.6 per cent), plant height (72.3 cm), No. of tillers (513 No./m2), dry matter production (9252 kg/ha), grain yield (5244 kg/ha) and straw yield (7920 kg/ha).This was comparable to the combination of triafamone + ethoxysulfuron followed by bispyribac sodium (T5). In contrast, the unweeded control plots recorded the lowest grain yield, which was accompanied by poor weed control and substantial weed growth parameters.