Weed management studies in transplanted rice (Oryza sativa L.)

Abstract:

An experiment entitled “Weed management studies in transplanted rice (Oryza sativa L.)” was undertaken at the Research-cum-Instructional Farm of Barrister Thakur Chhedilal College of Agriculture and Research Station, Bilaspur (C.G.), during the kharif season of 2024-25. The experimental layout followed a Randomized Block Design comprising three replications. The treatments consisted of seven weed management practices viz., (T1) Untreated check, (T2) Weed free, (T3) Hand weeding @ 30 DAT (once), (T4) Fenoxaprop-p-ethyl @ 60 g a.i./ha at 25 DAT, (T5) Bispyribac - Na @ 25 g a.i./ha at 25 DAT, (T6) Fenoxaprop-p-ethyl @ 60 g a.i./ha at 25 DAT + (Chlorimuron-ethyl + Metsulfuron methyl 20 g a.i./ha at 25 DAT) and (T7) Florpyrauxifen benzyl + Cyhalofop butyl (25+125 g/L) @ 150 g a.i./ha at 25 DAT. Observations on plant population, plant height, number of tillers and dry matter accumulation were recorded at different growth stages of the crop. Yield attributes such as number of panicles, panicle length, number of grains per panicle, test weight, grain yield and straw yield were recorded at harvest and subjected to statistical analysis. Total weed density was recorded at 30, 60 and 90 DAT and at harvest and analyzed statistically. Economic parameters such as cost of cultivation, gross return, net return and benefit: cost ratio was also determined. The weed-free treatment (T₂) recorded superior performance in terms of growth parameters, yield attributes, yield, as well as gross and net returns, followed by hand weeding at 30 DAT (once) (T₃). Among the chemical weed control treatments, application of Florpyrauxifen benzyl + Cyhalofop butyl (25 + 125 g L⁻¹) @ 150 g a.i. ha⁻¹ at 25 DAT (T₇) resulted in higher growth, yield attributes and yield of transplanted rice compared to other weed management practices. However, the highest benefit: cost ratio was obtained under Florpyrauxifen benzyl + Cyhalofop butyl (25 + 125 g L⁻¹) @ 150 g a.i. ha⁻¹ at 25 DAT (T₇). Hand weeding at 30 DAT (once) (T₃) proved to be the most effective treatment for controlling weed growth. Among the chemical weed management practices, Florpyrauxifen benzyl + Cyhalofop butyl (25 + 125 g L⁻¹) @ 150 g a.i. ha⁻¹ at 25 DAT (T₇) and Fenoxaprop-p-ethyl @ 60 g a.i. ha⁻¹ at 25 DAT + (Chlorimuron-ethyl + Metsulfuron methyl @ 20 g a.i. ha⁻¹ at 25 DAT) (T₆) were the next best treatments, demonstrating the potential to control a broad spectrum of weeds, including broad-leaved weeds, narrow-leaved weeds and sedges. Higher weed control efficiency at harvest was also recorded under these treatments.