Abstract

Three field experiments were conducted during 1976-77 to study the relative fficacy of certain insecticides (granule, spray and dust formulations) Bacillus thurin- giensis (B. t) and Nuclear Polyhedrosis Virus (NPV) in the control of redgram pod borers. Among the spray formulations, chlorphenamidine 0.1 per cent, endosulfan 0.07 per cent and carbaryl 0.25per cent were effective. In the dust formulations tried, endosul- fan was oustanding, followed by phosalone, carbaryl and quinalphos. Endosulfan and carbary! dusts were effective in the order, in significantly reducing the grain damage. In the combination experiment with dust, granule. B. t and NPV, endosulfan dust at 0.5 and 1.5 kg a. i./ha were superior followed by disulfoton granule (1.0 kg a. i/ha). The grain damage was substantially reduced by endosulfan dust 0.5 and 1.0 kg a.i/ha and disulfoton granule followed by 8. t treatment. Though B. t and NPV were able to reduce the infestation by the pod borers, they were not as effective as endosulfan dust.

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