Herbicide-based weed management on weed prevalence, crop productivity and profitability in transplanted rice

The efficacy of pre- and post-emergence herbicide-based weed control methods was evaluated and compared with hand weeding twice and weedy check in transplanted rice. Hand weeding twice (20 and 40 days after transplanting) was found to be significantly (p=0.05) effective in controlling various groups of weeds, resulting in 86.4% weed control efficiency (WCE) and a rice grain yield of 6.99 t/ha. Additionally, sequential application of pyrazosulfuron 20 g/ha followed by (fb) bispyribac-sodium 25 g/ha and pendimethalin 1000 g/ha fb bispyribac-sodium was found to be highly effective in providing prolonged weed control. Bispyribac-sodium applied alone showed 78% WCE, which was significantly better than fenoxaprop and pyrazosulfuron. Pre-emergence fb post-emergence herbicides were found to be more profitable (B: C of 2.13-2.23) and productive (6.58-7.17 t/ha). The findings suggested that the sequential application of pyrazosulfuron 20 g/ ha or pendimethalin 1000 g/ha fb bispyribac-sodium 25 g/ha could provide broad-spectrum weed control, higher crop productivity, and profitability in transplanted rice.