Comparative bio-efficacy of drone and knapsack applied sequential herbicides on growth and productivity of wet direct-seeded rice (Oryza sativa L.) (WDSR)

An agronomic investigation was conducted during the rabi season of 2024-25 at the B1 plot of the Indian Institute of Rice Research, Rajendranagar, Hyderabad, to assess the comparative bio-efficacy of drone- and knapsack-based herbicide sprays in Wet Direct Sown Rice. The trial was laid out in a randomized block design with six treatments and four replications. The treatments included pretilachlor 30% + pyrazosulfuron ethyl 0.75% WG @ 600 + 15 g a.i. ha^-1 (Ready mix) PE 3-5 DAS followed by triafamone 20% + ethoxysulfuron 10% WG 44 + 22.5 g a.i. ha^-1 (Ready mix) PoE 20-25 DAS, pretilachlor 30% + pyrazosulfuron ethyl 0.75% WG @ 600 +15 g a.i. ha^-1 (Ready mix) PE 3-5 DAS followed by penoxsulam 1.02% + cyhalofop-butyl 5.1% OD 135 g a.i. ha^-1 (Ready mix) PoE 20-25 DAS through drone and knapsack spray. Among these, pre-emergence application of pretilachlor 30% + pyrazosulfuron ethyl 0.75% WG @ 600 +15 g a.i. ha^-1 (Ready mix) at 3-5 DAS followed by penoxsulam 1.02% + cyhalofop-butyl 5.1% OD 135 g a.i. ha^-1 (Ready mix) PoE 20-25 DAS through drone spray resulted, in superior plant height (cm), no. of panicle m^-2, no. of filled grains panicle^-1, test weight (g), besides superior grain yield.