EVALUATION OF POST EMERGENCE HERBICIDES ON WEED CONTROL IN RICE NURSERY

A field experiment was conducted during rainy seasons of 2007-08 and 2008-09 to evaluate different post emergence herbicides like cyhalofop butyl 100 g ha-1, bis-pyribac-sodium20 to 50 g ha^-1, propaquizafop 50 g ha^-1, ethoxy sulfuron 15 gha-1, 2,4-d na salt 800 g ha^-1, alone and tank mixture of cyhalofopbutyl 100 g ha^-1 + ethoxy sulfuron 15 g ha-1 2,4-d nasalt 800g ha^-1 for broad spectrum weed control in rice nursery.results revealed that all the herbicidal treatments significantly reduced total weed density and dry weight over unweeded check. among the treatments, post emergence application of bis-pyribac-sodium 30 g ha^-1 applied 15 at das (days aftersowing) significantly reduced total weed density, dry weight and was on par with its higher doses of 40 and 50 g ha^-1 with weed control efficiency of 74 to 79 percent. among the treatments,post emergence application of propquizafop 50 g ha^-1 causedsevere stand loss of rice (90 percent) by 14 days after application. whereas, bis-pyribac-sodium at higher dose of 50 g ha^-1 also caused slight injury, but crop recovered with in 14 days after application. tank mixing of cyhalofop butyl 100 g ha^-1 with 2, 4-d na salt 800 g ha^-1 or ethoxy sulfuron 15 g ha^-1 didnot offer any additional advantage compared to bis-pyribacsodium 30 g ha^-1.