Grass weeds control in transplanted rice with Cyhalofop-butyl

This experiment was performed to determine the appropriate dose of Cyhalofop-butyl (CB) for controlling grass weeds in transplanted rice. CB at four doses, including 50, 100, 150, and 200 g ai/ha was investigated and compared with current herbicides in rice at recommended doses. The results showed that CB 100, 150, and 200 g ai/ha significantly reduced the density and dry matter of Echinochloa crusgalli (L.) P. Beauv. and Paspalum distichum L. over the weedy check; the minimum control efficacy of CB at these doses was 73.3 and 88.3% for E. crusgalli density and dry matter reduction, respectively, and for P. distichum, it was 80% for density and dry matter reduction. Applying CB at all doses (50- 200 g/ha) showed no crop injury symptoms on rice plants. The highest grain yield was obtained by hand weeding, CB 150 g ai/ha, and Tiobencarb treatments, with 5180, 5106, and 5051 Kg/ha, respectively. CB 200 g ai/ha was on par with CB 150 g ai/ha, and there was no significant variation between CB 100 and 200 g ai/ha in rice grain production. Finally, it was found that the application of CB 100 g ai/ha is an efficient grass weed control practice for improving the rice yield.