Effectiveness of neem (Azadirachta indica A. Juss) products and insecticides against rice leaf folder, Cnaphalocrosis medinalis Guenee

During 1993 and 1994 kharif seasons, the efficacy of different neem products, viz., neem cake (200 kg/ha basal application), neem cake (200 kg/ha basal application) + neem seed kernel extract (NSKE)5% (25 and 32 days after transplanting), NSKE 5%, neem leaf decoction (0.5 kg/one litre of water), and neem oil 3% was compared with chlorphyriphos 20 EC (0.5 kg a.i./ha) and quinalphos 25 EC (0.4 kg a.i./ha) against the rice leaf folder, Cnaphalocrosis medinalis Guenee under field conditions. Chlorpyriphos proved to be the most effective against the rice leaf folder, the leaf damage being 11.10 and 10.08 per cent after the first and second sprayings, respectively. Neem cake + NSKE 5% was the next best treatment, followed by quinalphos, neem seed kernel extract and neem oil. Both the applications of neem leaf decoction and neem cake proved least effective in reducing the percentage of damaged leaves due to rice leaf folder.