Insecticidal potential of indigenous plants leaf powder against rhyzopertha dominica fab. (coleoptera: bostrichidae) in stored maize (zea mays) grains in northeastern nigeria

Abstract

The study on the toxicity potential of plant leaf powders of Eucalyptus globulus, Citrus limon and Cassia occidentalis against maize weevil (Rhyzopertha dominica) infestation during storage was investigated in the Laboratory of the Department of Crop Protection, Faculty of Agriculture, Modibbo Adama University, Yola. The experiment was laid out in a Completely Randomized Design (CRD) with three replications and data collected were analyzed using General Linear Model Procedure of Statistical Analysis System (SAS, 2004) while, significance means will be compared using Duncan's Multiple Range Test (DMRT) at 5% probability level. Rhyzopertha dominica where exposed to four doses (0.2 g, 0.4 g, and 0.6 g) of these leaf powder per 50g of maize and a control treatment. Phytochemical analysis reveals the leaf powder of Eucalyptus globolus, Citrus limon, and Cassia occidentalis contain the following components (Saponin, Tanin, Steriod, Glycocide, Flavonoid, Tapinoid, Alkaloidand phenol). Though C. limon and C. occidentalis did not showed the presence of Tapinoid. The result of R. dominica mortality showed that at 3, 7, 14, and 21 days, highest mortality was observed on SAMMAZ 51 while SAMMAZ 15 had the lowest mortality. Mortality also of R. dominica on treated maize was highest at 0.6 g dosage, with effectiveness increasing over time. The Treated Maize exhibited less grain damage and weight loss compared to untreated controls. Germination percentage and palatability tests revealed no significant difference (P <0.05) between treated and untreated maize among the tested plant powders. C. occidentalis demonstrated the highest efficiency in controlling R. dominica which can be recommended as effective botanical insecticides for the control of R. dominica in stored maize, these offer a promising eco-friendly alternative for post-harvest pest management.