Non-chemical approaches for effective weed management and productivity of transplanted rice (Oryza sativa L.)

A field experiment was conducted at the wetland farm, Tamil Nadu Agricultural University, Coimbatore, during rabi 2022 and kharif 2024 to evaluate the non-chemical weed management practices in transplanted rice. The study aimed to assess weed parameters including weed flora, total weed density, total weed dry weight, Weed Control Efficiency (WCE) and Weed Index (WI), along with their impact on grain yield. The experiment consisted of twelve treatments laid out in a Randomized Block Design (RBD) with three replications. The findings revealed that hand weeding at 20 and 40 Days After Transplanting (DAT) recorded the lowest total weed density with 19.9, 34.0, 46.0, 44.0 weeds m-2 in rabi 2022 and 24.3, 41.0, 58.1, 51.9 weeds m-2 in kharif 2024, the lowest total dry weight with 5.22, 5.89, 8.91, 10.15 g m-2 in rabi 2022 and 5.39, 6.33, 9.40, 10.92 g m-2 in kharif 2024, the highest WCE with 72.60 %, 79.22 %, 66.37 %, 68.73 % in rabi 2022 and 71.16 %, 77.02 %, 64.35 %, 64.47 % in kharif 2024, the lowest WI of 1.6 % in rabi 2022 and 1.4 % in kharif 2024 at 30, 45, 60, 80 DAT respectively, resulting in the highest grain yields of 5326 kg ha-1 in rabi 2022 and 5245 kg ha-1 in kharif 2024. This was followed by Butachlor @ 1 kg/ha at 3 DAT as pre-emergence and Bispyribac sodium @ 25 g/ha at 25 DAT as post emergence. Among non-chemical practices, foliar spray of ITK-based farmers’ practices (cow urine + lime solution + khadi soap + common salt) at 25 DAT + hand weeding at 40 DAT was most effective with total weed density of 5.06, 6.09, 7.53, 7.56 weeds m-2 in rabi 2022 and 5.52, 6.7, 8.2, 8.2 weeds m-2 in kharif 2024, total weed dry weight of 5.82, 7.36, 9.71, 12.13 g m-2 in rabi 2022 and 5.97, 7.50, 9.86, 12.37 g m-2 in kharif 2024, WCE of 65.53, 67.09, 59.98, 55.25 % in rabi 2022 and 64.51, 67.53, 60.78, 54.38 % in kharif 2024, WI of 3.2 in rabi 2022 and 2.4 in kharif 2024 at 30, 45, 60, 80 DAT respectively, with grain yield of 5235 kg ha-1 in rabi 2022 and 5198 kg ha-1 in kharif 2024. The current study aims to evaluate the effect of non-chemical weed management in transplanted rice.