Contact toxicity of oil, powder and extracts of garlic (Allium sativum) against Callosobruchus chinensis (L.) in chickpea seeds

The studies investigated the contact toxicity of various garlic (Allium sativum) formulations including oil (0.5, 1.5%), powder (2, 4%), and solvent extracts methanol, hexane, chloroform and acetone (2, 3%) against Callosobruchus chinensis (L.), a major pest of stored chickpea seeds. Laboratory bioassays were conducted by treating chickpea seeds with garlic products and exposing adult beetles to evaluate mortality over time at 45 days intervals up to six months post-treatment at CCS Haryana Agricultural University, Hisar. Garlic oil (1.5%) showed the highest and most persistent efficacy, causing 100% mortality within 24 h initially and maintaining effectiveness even six months post-treatment. Methanol and hexane extracts (3%) were effective initially, causing complete mortality within 3-5 days, though their effectiveness declined over time. Garlic powder was less effective initially but achieved 100% mortality by day 7. Efficacy of most treatments declined after 90-135 days, but garlic oil remained consistently potent. The results support garlic oil as a promising, eco-friendly alternative to synthetic insecticides for protecting stored chickpeas from C. chinensis.