Comparative Efficacy of Aqueous Extracts of Lime (Citrus aurantifolia) and Grape (Citrus paradisi) Peel in the Control of Callosobruchus maculatus (F.)

NJE Vol. 38: 41-49, 2022


Uddin II, R. O.*, Omolale, O. O. and Ogundare O. P.

Department of Crop Protection, Entomology Unit, Faculty of Agriculture, University of Ilorin
PMB 1515, Ilorin, Nigeria

A laboratory study was conducted in the Department of Crop Protection, University of Ilorin, to evaluate the single and mixed insecticidal action of aqueous extracts of grape (Citrus paradisi) and lime (Citrus aurantifolia) peel in the control of cowpea beetle, Callosobruchus maculatus. The experiment was laid out in a completely randomized design. There were four treatments with three replicates per treatment. The treatments were applied at the following rates, 0.5ml, 1.0ml, and 1.5ml per 100g of cowpea seeds. The following parameters were used to assess the efficacy of the treatments; adult mortality, oviposition, number of larvae, number of pupae and F1 progeny emergence. The findings of this experiment showed that 1.0 ml of aqueous peel extract of grape + lime had significantly higher female mortality compared to control at 3rd and 5th DAT. Aqueous peel extract of lime caused a significantly lower (70.67 + 4,3) oviposition rate compared to control (141.33+ 7.4) at 2 DAT with 1.5 ml being the most effective rate of application at 4 DAT. Aqueous peel extracts of lime was most effective in significantly reducing larval emergence (1.33 + 0.3) compared to control (8.33 + 0.5). The trend was similar for pupal emergence. Aqueous peel extracts of grape was most effective in reducing male F1 progeny emergence while lime was most effective in reducing female F1 progeny of C maculatus. Aqueous peel extract of lime could be included in control measures used by local farmers in storage of their grains for two months.

Keywords: Botanicals, cowpea, damage, storage, weevil.

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