Vol. 8, Issue 8, Part N (2024)

Abstract: A field experiment was conducted at the Agricultural Farm, Department of Agronomy, Palli Siksha Bhavana, Visva-Bharati, West Bengal, during the monsoon season 2022 (kharif) to investigate the impact of encapsulated metsulfuron methyl on improved weed management in transplanted rice. The study was undertaken using a randomized block design (RBD) with eleven treatments and each replicated thrice. The treatments included, four different doses of encapsulated and commercial metsulfuron methyl viz., 2 g a.i ha^-1, 3 g a.i ha^-1, 4 g a.i ha^-1 and 5 g a.i ha^-1. These treatments were compared with the farmers practice of hand weeding twice at 20 and 40 days after transplanting. The weed free check and unweeded control treatments were maintained for assessing the weed control efficiency of commercial and encapsulated metsulfuron methyl. Both formulations of metsulfuron methyl were applied as pre emergence on five days after transplanting and the solvent evaporation method was utilized for encapsulating metsulfuron methyl. The findings demonstrated that, among the herbicidal treatments, pre emergence application of encapsulated metsulfuron methyl at 5 g a.i ha^-1 achieved the higher weed control index (97.23%), greatest number of productive tillers (353), maximum grain yield (5593 kg ha^-1), superior straw yield (7629 kg ha^-1) and more return per rupee invested (₹. 1.56) than other treatments. However, this was closely followed and statistically at par with all the encapsulated metsulfuron methyl treatments. Interestingly, the encapsulated metsulfuron methyl 2 g a.i ha^-1 recorded a significant weed control index (92.99%), higher number of productive tillers (336), substantial grain yield (5055 kg ha^-1), impressive straw yield (7166 kg ha^-1) and elevated return per rupee invested (₹. 1.37) than recommended dose of commercial metsulfuron methyl 4 g a.i ha^-1. This indicates that, the recommended dose of metsulfuron methyl can be reduced by half when using the encapsulated formulation. In conclusion, considering the ecological balance, environmental sustainability and shortage of skilled agriculture labour, pre emergence application of encapsulated metsulfuron methyl at 2 g a.i ha^-1 on five days after transplanting is optimal for superior weed control, higher productivity and profitability of transplanted rice.