Bioefficacy of Fenpropathrin 30% EC for the control of the rice leaf folder, Cnaphalocrocis medinalis (Guen.)

摘要

A field experiment was conducted at OdishaUniversity of Agriculture and Technology, Bhubaneswar with seven treatments during wet and dry season 2008-2009 to evaluate the bio-efficacy of fenpropathrin 30% EC against the rice leaf folder, Cnaphalocrocismedinalis (Guen.) and its safety to natural enemies The results revealed that the per cent leaf damaged was the lowest (1.29-1.81) at 15 days after spraying (DAS) in the treatments fenpropathrin 30%EC @ 75,100 and 125g a.i.ha~(-1) registering 84.65-89.06 per cent decrease in leaf damage over control (11.79 %> leaf damage) compared to the standard check insecticides evaluated. The rice grain yield recorded significantly highest (3.94-3.98 t ha~(-1)) in the treatments fenpropathrin 30%EC @ 100 and 125g a.i. ha~(-1) with 28.43-29.14 per cent increase over control. All the insecticides evaluated proved toxic to the natural enemies, however, at 10 DAS, their population built up in all the doses of fenpropathrin was at par with control while lambda-cyhalothrin and triazophos still proved toxic.