Effect of weed management practices with new generation herbicides in transplanted rice

Abstract

A Study was conducted during Samba season of 2017 to evaluate the efficacy of pre and post emergence herbicides in transplanted rice in Cuddalore district. The new herbicides evaluated were Pretilachlor 6% + Pyrazosulfuron-ethyl 0.15% GR @ 10 kg ha-1 along with post emergence herbicides Fenoxaprop-p-ethyl 9.3% w/w @ 875 ml ha-1, Bispyribac-sodium 10% SC @ 200 ml ha-1. Results of the study revealed substantial reduction in weed biomass in all the herbicide treated plots compared to weedy check. Pre-emergence herbicide application followed by application of post emergence herbicides recorded lower weed control efficiency. The highest grain yield (5163 kg ha-1), straw yield (7654 kg ha-1), net return (Rs. 52070 ha-1) and BCR (2.52) were obtained with application of Pretilachlor 6% + Pyrazosulfuron-ethyl 0.15% GR @ 10 kg ha-1 on 3 DAT + Bispyribac-sodium 10% SC @ 200 ml ha-1on 20 DAT (T7). The least weed biomass, grain and straw yield, net income and return rupee-1 invested were accounted with un weeded check. On the basis of the above results, it can be concluded that application of Pretilachlor + Pyrazosulfuron-ethyl + Bispyribac-sodium (T7) hold promise as an appropriate method of weed management for obtaining higher yield and net income in transplanted rice and it was on par with twice hand weeding.