Central Rice Research Institute, Cuttack-753 006.
*Present Address: All India Coordinated Rice Improvement Project, Hyderabad - 500 030.
Chlorpyrifos as seedling root soaking at 0.02 per cent concentration remained effective for a period of 30–40 days and checked the infestation of gall midge, stem borer and whore maggot, but did not prevent leaf folder damage which was effectively controlled by carbofuran granules at 0.75 kg a.i./ha broadcasted at 5 days after transplanting. Highest cost benefit ratio was obtained in the case of chlorpyrifos seedling root soaking in all the seasons of testing except in Rabi 1983, over the conventional granular application with phorate, carbofuran or quinalphos, especially for gall midge control. In addition to chlorpyriphos, seedling root soaking with Evisect, carbosulfan, isofenphos and endousulfan was also found Proomising for the early stem borer control whereas carbofuran and carbosulfan as seediling root soaking were ineffective against gall midge.