Effect of oxyflourfen for weed control in dry-sown rice

Abstract

A field experiment was conducted at Regional Agricultural Research Station, Pattambi of Kerala Agricultural University during the first crop seasons of 1991 and 1992 to find out the time and dose of application of oxyflourfen in dry-sown rice. The treatments included different doses of oxyflourfen (0.05, 0.10, 0.15 and 0.2 kg a.i./ha) on the same day of sowing, at 3 and 6 DAS, butachlor and Thiobencarb (1.5 kg a.i./ha) on the same day of sowing and two controls (weedy check and hand weeded check) laid out in randomised block design with three replications. The results showed that the count, dry matter production and nutrient removal of weeds were appreciably reduced by the weed control treatments particularly by oxyflourfen application @ 0.15 kg a.i./ha on the same day of sowing during initial stages and oxyflourfen application @ 0.2 kg a.i./ha at 3 DAS during later stages. The weed control efficiency was highest during critical stages in oxyflourfen applied plots @ 0.15 kg a.i./ha on the same day of sowing and was even higher than that of hand weeding and the effect was on par with oxyflourfen application @ 0.2 kg a.i./ha at 3 DAS. Oxyflourfen application @ 0.2 kg a.i./ha at 3 DAS gave significantly higher values of yield attributes viz. productive tillers, panicle length and number of filled grains per panicle resulting in higher grain yield and the effect was on par with hand weeding. These treatment showed highest straw yield also. The weed index values were lower in plots where, oxyflourfen @ 0.2 kg a.i./ha at 3 DAS were applied. In terms of returns per rupee invested also, plots treated with oxyflourfen @ 0.2 kg a.i./ha at 3 DAS was the best. Among the different levels of oxyflourfen, a dose of 0.2 kg a.i./ha at 3 DAS can be advocated for better weed control efficiency, higher yield and net return.