Effect post-emergence herbicide on weed control and weed control efficiency, weed index and yield in direct seeded rice (Oryza sativa L.)

Direct-seeded rice (DSR) has emerged as a popular alternative to traditional transplanting due to its cost-efficiency and labor-saving benefits. However, weeds significantly threaten DSR productivity. The experiment was laid out in Randomized Block Design with three replications to find out the suitable weed management practices on growth and yield of rice crop, to assess the losses in yield of rice caused due to weeds, and economics of different treatments. Field trial was laid out in RBD with three replications, Ten treatments viz. T₁: Chlorimuron Ethyl 25% WP @ 37.05 g a.i./ha (PoE), T₂: Bispyribac sodium 20% + pyrazosulfuron 15% WDG @ 52.50 g a.i./ ha+ Spreadmaxa@ 0.5 ml litre-1(PoE) T_3: Bispyribac sodium 20% + pyrazosulfuron 15% WDG @ 61.25 g a.i./ ha+ Spreadmaxa @ 0.5 ml litre-1(PoE), T₄: Bispyribac sodium 10% SC @ 25 ml a.i./ha (PoE), T₅: Pyrazosulfuron 10% WP@ 215g a.i./ha (PoE), T₆: Triafamone 20% + ethoxysulfuron10% WG @ 66.5 g a.i./ha (PoE), T₇: Penoxsulam 1.02% + cyhalofop-butyl 5.1% OD @ 135 ml a.i./ha (PoE), T₈: Fenoxoprop (PE) fb Halosulfuron @ (56 fb 67) ml a.i./ha (PoE), T₉: Hand weeding (20 and 40 DAS) and T₁₀: untreated control,. Among the herbicides tested, T_3: Bispyribac sodium 20% + pyrazosulfuron 15% WDG @ 61.25 g a.i./ ha+ Spreadmaxa @ 0.5 ml litre-1(PoE), and being at par with T₂: Bispyribac sodium 20% + pyrazosulfuron 15% WDG @ 52.50 g a.i./ ha+ Spreadmaxa@ 0.5 ml litre-1(PoE), showed superior weed control, better growth parameters, and increased yields. Additionally, T₇: Penoxsulam 1.02% + cyhalofop-butyl 5.1% OD @ 135 ml a.i./ha (PoE), (T7) effectively controlled Paspalum Monspeliensis. The study highlights the need to tailor weed control methods to local conditions, selecting appropriate herbicides and practices based on the prevalent weed species in the farming system. Understanding the specific effects of post-emergence herbicides is vital for effective weed management in direct-seeded rice.