Efficacy of Certain Plant Oils as Seed Protectant against Pulse Beetle, Callosobruchus chinensis Linn. on Pigeonpea

Efficacy of some indigenous plant oils viz castor, eucalyptus, sunflower and neem oil @ 5 and 10 mL kg⁻¹ of seeds against pulse beetle on pigeonpea was studied. The observations after 6 months of fteatment tevealed that the mean number of eggs laid per 100 seed was least in neem oil 5 mL and 10 mL (4.4 and 9.6) followed by sunflower oil 11 mL (27.0) as against 202.3 in untreated check. The findings after 9 months of treatment also revealed that neem oil @ 10 mL and 5 mL per kg of seeds was highly effective against C. chinensis reristering the minimum seed damage of 9.2 and 15.0% as against 96.0% in untreated check. The number of eggs laid were also minimum in these treatments (56.4 and 105.8 per 100 seeds) as against 492.4 eggs in control. The loss in seed weight was also less in neem oil (10.6 and 14.5% in 10 and 5 mL, respectively) followed by castor oil 10 mL (22.8%) when compared to 49.9% in control.