Abstract

Asawalam E. F. and A. L. Chukwuekezie

Maize (Zea mays [L.]) is a major staple food in many regions of the world. The maize weevil Sitophilus zeamais is a serious primary pest of maize in Nigeria. Laboratory investigations were carried out to compare the efficacy of the extracts of Curcuma longa rhizomes and Gnetum africanum leaves for the control of S. zeamais on stored maize grains. Three different solvents namely: petroleum ether, methanol and acetone were used to extract the essential oils from C. longa rhizomes and G. africanum leaves using a soxhlent extractor apparatus. The extracted oils were evaluated on S. zeamais for mortality effect. Weight loss of the maize grains was also assessed. The experiment was laid out in a completely randomized design (CRD) in four replications. The results obtained showed that the essential oil of C. longa extracted with petroleum ether evoked significantly (P ≤ 0.05) higher mortality (90%) in the maize weevil at 42 days after treatment (DAT). It also recorded a significant reduction in percentage weight loss when compared with the control treatments. No mortality was recorded in the control of all solvents and untreated control. C. longa extracted with petroleum ether was very effective in controlling S. zeamais in stored maize grains and can be incorporated for the control of S. zeamais in stored maize grains.