Evaluation of the effectiveness of Bidens pilosa as a grain protectant against maize weevil (Sitophilus zeamais) in stored maize

Abstract

Maize is one of the major staple food crops. However, maize weevil infestation causes large post-harvest losses during storage. Even though synthetic insecticides are frequently used to manage storage pests, there is a growing need for more sustainable alternatives. The study was conducted to evaluate the effectiveness of Bidens pilosa powder as a grain protectant against Sitophilus zeamais in stored Zea mays. The experiment was carried out under laboratory conditions at Astra Campus using a Complete Randomized Design (CRD) with six treatments replicated three times. The treatments consisted of 0g (control), 5 g, 10 g, 15 g, 20 g and 25 g of Bidens pilosa powder mixed with 10 g (33 kernels) of clean maize grains. Each experimental unit was infested with fifteen adult maize weevils. Data was collected on maize weevil mortality, grain damage and weight loss after 4, 6, 8 days of storage. The highest mortality was recorded in the 25 g treatment showing that increasing the concentration of Bidens pilosa powder significantly has an effect on maize weevil whilst the control treatment recorded the lowest mortality throughout the experiment. Grain damage and weight loss increased rapidly with storage duration in all treatments. The highest grain damage and weight loss were observed in the control treatment, whereas the lowest values were recorded in treatments with 20 g and 25 g of Bidens pilosa. Analysis of variance revealed highly significant differences among treatments for all measured parameters (P < 0.001). The coefficients of variations were below 20%, indicating the reliability of the results. The study concluded that Bidens pilosa powder is effective in controlling maize weevils and reducing grain damage and weight loss in stored maize. Higher concentrations of 20 g and 25 g provided the greatest protection against maize weevil infestation. Therefore, Bidens pilosa powder has potential for use as it is affordable, environmentally friendly and sustainable botanical grain protectant