Weed management practices in direct seeded rice ecosystem in north western zone of Tamil Nadu

Field experiments were conducted to study the cost effective weed management practices in direct seeded rice at Regional Research Station, Tamil Nadu Agricultural University, Paiyur 635 112, Tamil Nadu, India in wet and dry seasons of 2015 and 2016 respectively in randomized block design with four replications. The treatments are preemergence application of Pendimethalin @ 1.0 kg ai ha at 8 DAS followed by hand weeding at 25 DAS (T1), preemergence application of Pendimethalin @ 1.0 kg ai ha at 8 DAS followed by post emergence application of Bispyribac sodium 25 g ha at 25 DAS+ hand weeding at 45 DAS (T2) and Cono weeder weeding at 10 and 25 DAS (T3), Hand weeding on 15 and 30 DAS (T4) and Control Weedy check (T5). The results revealed that, among the different weed control treatments, application of pre-emergence herbicide pendimethalin 1.0 kg ai ha at 8 DAS with POE Bispyribac sodium 25g ha at 25 DAS and HW on 45 DAS (T2) recorded higher grain yield of 6438 kg ha -1 with the B:C ratio of 2.77. With respect to weed control efficiency, application of pre-emergence herbicide pendimethalin 1.0 kg ai ha at 8 DAS with POE Bispyribac sodium 25g ha at 25 DAS and HW on 45 DAS (T2) recorded higher weed control efficiency of 81.0 % as compared with Cono weeder weeding at 10 and 25 DAS. Hence, it was concluded that considering the weed control efficiency, yield and economics, pre-emergence application of pendimethalin 1.0 kg ai ha at 8 DAS with POE Bispyribac sodium 25g ha at 25 DAS and HW on 45 DAS is recommended for weed management in direct seeded puddled rice to meet the challenges against labour scarcity and weed infestation in the field of small and marginal farmers.