Anda, D.A.Ajayi, Folorunso A.2023-12-112023-12-112012-09-16D. A. Anda1* and F. A. Ajayi2 1Department of Agricultural Technology, College of Agriculture, P.M.B. 33, Lafia, Nasarawa State, Nigeria 2Department of Agronomy, Nasarawa State University, Keffi, Shabu–Lafia Campus, P.M.B 135, Lafia, Nigeriahttps://keffi.nsuk.edu.ng/handle/20.500.14448/3019Two edible plant product powders, West Africa black pepper (Piper guineense Schum and Thorn) and Horseradish (Moringa oleifera Lam) were studied for effectiveness in controlling the cowpea seed bruchid (CSB) Callosobruchus maculatus (F.) in the Agronomy Laboratory, Collage of Agriculture, Lafia. A completely randomized design (CRD) consisting of three treatments (root–bark, leaf and seed powders) each at three dosage rates of 0.5, 0.75, 1.00 g were admixed with 30 g of cowpea seeds in three replications contained in plastic cups with a lid. Untreated control was also provided. 10 pairs of 3 day old adult C. maculatus were introduced into each plastic container and allowed to mate and oviposit. Adult mortality was taken at 24 hourly for a period of 7 days. Number of eggs laid was taken from 10 randomly selected seeds from each treatment and replicate. The entire plant product powders significantly (p < 0.05) reduced oviposition by C. maculatus. Also, significant (p < 0.05) result was observed in grains treated with seed powders of the two plants. Adult emergence decreased with time among seeds treated with the plant products and increased in time among the seeds without treatment (control). There were however significant differences (p < 0.05) between the edible plant powders and the control treatment at all dosage rates tested. The effectiveness of the seed powders for the two edible plants was significantly higher when compared with the leaf powder and the root bark. Thus, can be ranked as follows: seed powder > root–bark > leaf powder.enCowpea beetle, Callosobruchus maculatus, Moringa oleifera, Piper guineense.Article