TOXICITY OF SOME BOTANICAL POWDERS ON MAIZE WEEVIL Sitophilus Zeamais MOTSCHULSKY 1855 (COLEOPTERA: CURCULIONIDAE)

Abstract

Maize production system is challenged by a lot of biotic and abiotic stressors. Among the biotic stressors, the maize weevil is infamous for causing severe damage to stored maize, reducing both qualitative and quantitative qualities. Incessant use of synthetic insecticide to manage maize weevil has led to a public outcry and a need for more eco-compatible options. Botanicals provide a cheap, safe and easy-to-make, and eco-friendly option for maize weevil management. This study was designed to assess the toxicity of four medicinal plant powders on some parameters of maize weevil. The study was conducted in June-July, 2020 in the Food Science laboratory of Catholic University of Cameroon, Bamenda. Plant powders of Carica papaya seeds, Cupressus macrocarpa leaves, Piper nigrum seeds and a control (no-input) were assessed. All the parameters assessed were significantly influenced by botanical powders (P < 0.05). The highest F1 emergence suppression was observed from piper treatments, followed by cypress and pawpaw treatments. The highest and lowest maize weight loss after storage were 21.0g and 13.25g from control and piper treatments respectively. The highest germination percentage was 95.0%, followed by 80.0%, 75.0% and 52.5% from piper (bush pepper or black pepper, cypress, pawpaw and control treatment, respectively. High repellency potential was observed from botanicals and that of piper can be described as a ‘very good repellant’ and ‘good repellant’ for the other botanicals. The highest adult weevil mortality was 80.05, recorded from piper. The current study demonstrate that botanical powders can play a significant role in maize weevil management. Piper seed powder is highly recommended for management of maize weevil. In addition, it is recommended that botanical powders be incorporated into integrated pest management strategies in order to guarantee safe, healthy and quality maize in storage. Such activities are in line with the objective of sustainable development goals (SDG).