Vol. 1, Issue 1 (2016)
Entomotoxic effect of tobacco seed extracted with different solvents against Callosobruchus maculatus infesting stored cowpea
Author(s): Olusola M Obembe, Olaniyi C Ogungbite
Abstract: Methanol, ethanol, acetone, pet-ether, n-hexane and aqueous extracts from Nicotiana tabacum seeds were investigated for their Entomotoxic effect against Callosobruchus maculatus. The potency of these extracts as grain protectant against C. maculatus was investigated using mortality, oviposition, adult emergence and viability as indices. The ability of the extracts to protect the seeds from damaging after long time of storage was also investigated. The result showed that pet-ether, n-hexane and aqueous extracts were very effective, causing 100% mortality of adult C. maculatus by 96 h of exposure to the extracts. While the other extracts (methanol, ethanol, and acetone) showed 80%, 85.20% and 70.15% mortality respectively. The extracts considerably reduced oviposition and adult emergence to the extent that no adult emerged in cowpea seeds treated with pet-ether and n-hexane extracts. All the extracts drastically reduced seed damage during storage for a period of 3 months. No damage was observed in seeds treated with acetone, pet-ether and n-hexane extracts. Most of the treated seeds also germinated after storage for a period of 90 days. The result of this investigation showed that all the extracts from tobacco seeds are very effective in controlling C. maculatus.