ISSN 2360-7971
Abstract
Two laboratory trials were conducted at the Department of Crop Protection, Faculty of Agriculture, Ahmadu Bello University, Samaru-Zaria, to evaluate the efficacy of five plant species. Anogeissus leiocarpus Guill. and Pel., Antidesma venosum Tull., Maranthes polyandra (Benth) Prance, Mitragyna inermis (Willd) Kuntze, and Vitex madiensis Olive were tested for their seed powders at two levels of concentrations (5.0 and 10.0 g/100 g seeds) as protectants against Callosobruchus maculatus F. infecting stored bambara groundnuts. Actellic dust 2.0% at 2.0 g/100 g seeds (treated check and untreated control) was placed alongside these plant seed powders to serve as checks. Treated and untreated experiments were infested with C. maculatus under prevailing storage. Antidesma venosum (AntSP) at 10g/100g seed recorded conditions. The two trials were consistent with each other. 45.9% mortality of C. maculatus in 24 hours post-treatment. Anogeissus leiocarpa (AnoSP) at a higher level had 61.7% mortality, and Maranthes polyandra (MarSP) had 43.5% mortality at 24 hours of treatment. At 48 hours post treatment, Vitex madiensis (VitSP) at both concentration levels recorded 56.3% and 57.9% mortality of C. maculatus. At 72 hours post treatment, AnoSP and VitSP, all at higher concentration levels, recorded 48.8% and 68.8% mortality of C. maculatus. The treatments VitSP, AnoSP, and MarSP resulted in low oviposition, with 5.64 and 6.76 eggs recorded, respectively. Treatments with MarSP, AntSP, MitSP, and AnoSP, all at 10 g/100 g seeds, recorded low F₁ progeny emergence of 1.73, 2.04, and 2.27, respectively. At 8 weeks, MarSP at both levels completely suppressed and inhibited F₃ filial progeny emergence, and on post-treatment, MarSP suppressed and inhibited the development of F₂ progeny emergence of C. maculatus. At 12 weeks, MarSP at both levels completely suppressed and inhibited F₃ filial progeny emergence and was on par with the Actellic 2.0 g/100 g seeds treatment, which recorded no F₃ filial progeny emergence. Seed damage and weight loss were relatively low in treatments using MarSP at 5.0 g and 10.0 g per 100 g of bambara groundnut seeds 12 weeks post-treatment. Moderate weight loss and seed damage were observed in all treatments using plant seed powder at 8 weeks post-treatment, particularly at higher concentration levels. Maranthes polyandra can be recommended to farmers for long-time storage of bambara groundnut, an alternative to synthetic chemicals like Actellic dust.
Keywords: Bioinsecticide, leguminous crops, stored products, insect antifeedant.