Effect of irrigation regimes and chemical weed management practices on weed density, weed dry matter, weed control efficiency and yield of transplanted rice (Oryza sativa L.) in command area

A field experiment was conducted at Agricultural College and Research Institute, Killikulam during early Pishanam season of 2018-2019 to study the effect of different irrigation regimes through field water tube and chemical weed management practices on weed density, weed dry matter, weed control efficiency and yield of transplanted rice. The experiment was laid out in strip plot design with three replications. The treatments comprised of three different methods of irrigation in vertical strips and four methods of weed management practices in horizontal strips. The results showed that, continuous submergence registered lower individual and total weed density and weed dry matter production with higher weed control efficiency at 15, 30 and 45 DAT than field water tube method of irrigation at 10 and 15 cm depletion. likewise, maintaining weed free condition recorded lower individual and total weed density and weed dry matter with higher WCE of 98.7 per cent and it was comparable with the application of PE Pyrazosulfuron ethyl @ 20g a.i. ha-1 fb POEBispyribac sodium @ 25 g a.i. ha-1. The higher grain and straw yield (6882 and 7675 kg ha-1) of rice was recorded in continuous submergence coupled with weed free environment. However, field water tube at 10 cm depletion + application of PE Pyrazosulfuron ethyl @ 20g a.i. ha-1 fb POEBispyribac sodium @ 25 g a.i.ha-1 produced the on par yield.