Abstract

Two experiments were conducted at the University of Uyo Teaching and Research Farm in 2003 and 2004 to evaluate the impact of aqueous extracts of five local spices as biopesticides for the control of O. mutabilis and C. tomentosicollis on cultivated cowpea (Vigna unguiculata L.). The spices evaluated were Capsicum annum L., Xylopia aethiopica (Dunal), Piper guineense Schum and Thonn, Allium sativum L. and Zingiber officinale Roscoe. The extracts were applied at 3, 4 and 5% concentrations, respectively to study toxicity, repellency, pod and leaf damage as well as grain yield. The experiment was designed as a Randomized Complete Block Design and replicated three times. Results obtained showed that the biopesticides significantly (P<0.05) reduced insect population, offered greater protection and promoted better grain yield compared to the control. However, amongst the spices, P. guineense consistently induced greater protection by bringing down the population of insects and promoting grain yield. The promising use of spices as biopesticides is discussed since they are available local resources for poor farmers and are environmentally friendly options for pest control.

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