Evaluating Tillage Practices and Herbicide Applications for Improved Rice Yield and Weed Control

Weed infestation, water scarcity and intensive tillage practices are resulting in low yield of rice crop. Direct seeded rice (DSR) and alternate wetting and drying (AWD) have emerged as alternative and resource efficient rice production methods. A field experiment was conducted to study the effect of weed control methods on weed management in rice under different tillage practices at research field of Department of Agronomy, Faculty of Agricultural Sciences, University of the Punjab, Lahore during rice growing season in 2022. The experiment was carried out in two factorials randomized completely block design (RCBD) with three replications. First factor had four tillage practices [Puddling; Alternate wetting and drying; Direct seeded rice (Drill sowing) and direct seeded rice (Broadcast sowing)] and second factor had four weed control treatments [Control; Pre-emergence weed control (Pendimethalin 33 % EC @ 1000 g a.i. ha-1; Post-emergence weed control (Bispyribac sodium (18 % w/w) + Bensulfuron methyl (12 % w/w) @0.15 a.i. Kg ha-1 and combination of pre+ post emergence weed control]. In the experiment, 12 weed species from 7 families were observed as part of the weed flora. Among them 6 were grasses, 1 sedge and 5 broadleaf weeds. Under AWD, a combination of pre- and post-emergence herbicide spraying resulted in the greatest weed species reduction (14.34/m2). Herbicides applied as pre+ post emergence produced the highest grain production (7.60 t ha-1) under puddling and it was statistically similar to grain yield acquired in application of pre-emergence weed control under AWD. In direct seeded rice highest grain yield (6.02 t ha-1) was produced by application of both pre+ post emergence herbicides under broadcast sowing. The potential yield loss was higher in drill sowing when no herbicide was used or only post- emergence herbicide was applied. AWD is found most promising technology with respect to production and resource conservation.