Effect on germination and nutrient composition of storing cowpea [Vigna unguiculata (L.) Walp.] seeds in a hermetic atmosphere modified with essential oil vapour from leaves of sweet basil [Ocimum basilicum (L.)]
Keywords:Callosobruchus maculatus, Ocimum basilicum, essential oil, hermetic storage, cowpea
AbstractCowpea represents an important staple crop in Sub Saharan Africa and can play significant roles in ensuring food security in that part of the world. During storage, the grains are attacked and decimated by the cowpea bruchid, Callosobruchus maculatus (F). Methods such as hermetic storage and treatment with botanical insecticides have been recommended as safer and cheaper protection alternatives for cowpea grain, than conventional insecticides. When used in combination, these two prove to be faster and more effective in killing resident C. maculatus adults at the commencement of storage and also adults that may later emerge from any parasitized seed in the course of storage. Grains so protected will however be of little value if the germination and nutrient composition of the cowpea seeds are adversely affected by the botanically modified storage atmosphere. In this study, an insecticidal atmosphere within hermetic plastic structures was created using essential oil from leaves of Ocimum basilicum (L.) on filter papers. Cowpea seeds stored hermetically for 30 and 60 days in the presence or absence of the botanically modified atmosphere were subjected to germination tests and proximate analyses. Results showed that the presence of the insecticidal atmosphere during storage did not negatively affect the germination and nutrient composition of the seeds.