23 Kas 2024 Cumartesi
Evaluation of the effectiveness of some plant powders on the management of the maize weevil, Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae) in the Bako area, western Ethiopia
Abstract : The effectiveness of powders made from Allium sativum, Capsicum annum, Zingiber officinale, Lantana camara, and Croton macrostachys as insecticides against S. zeamais was examined in the experiment. The evaluation was aimed at generating natural product treatments suitable for post-harvest grain protection and as sustainable alternatives to synthetic insecticides in the control of the maize weevil, S. zeamais. Three rates (4, 8, and 12 g) of each powder, a synthetic insecticide, Malathyon 5% dust at 2 g, and an untreated control were tested for their efficacy on mortality, F1 adult emergence, and maize grain damage under controlled conditions of 26±2°C and 71.5±3 °RH. The treated grains were infested with 25 pairs of unsexed S. zeamais. All insects were removed after 28 days to assess mortality. The experiments were monitored for 56 days to count F1 emerging adults. All tests were carried out in a complete randomized design (CRD) replicated three times, and the data generated were subjected to an analysis of variance (ANOVA). The results showed that the effects of botanicals on adult weevil mortality differed significantly between the experimental and control groups (P< 0.05). The highest mortality (98.7%) was in C. macrostachys at the rate of 12 g treatment, and the smallest (25.7%) was in C. annum at the rate of 4 g treatment, compared to the untreated control (24.0%). With the highest rate of powder treatments, the number of F1 adults emerged, and the percentage of grain damage was significantly (P< 0.05) reduced. Plant powders of C. macrostachys and L. camara were found to be more effective than other treatments in preventing adult emergence and reducing grain damage. This study shows that C. macrostachys and L. camara could be used to protect stored maize from S. zeamais infestations. Therefore, small-scale farmers are advised to use them to control S. zeamais in stored grains.