Integration of botanicals and inert dusts with resistant varieties against Sitophilus zeamais (Motsch.) of stored maize (Zea mays) in Ethiopia

Abstract

Dosage rates of 0.625, 1.25 and 2.5% of the leaves powder of Calpurnia aurea and Milletia ferruginea, and red and white inert dusts that were admixed with the 100 g of three resistance maize varieties were tested as protectant against maize weevils under laboratory condition. Significantly (p < 0.05) higher parental adult weevil's mortality were recorded in all treatments of integration than untreated check at almost all days (except first day) after treatment. Mortality effects of the tested integrated components were also increased both with increased dosage and days after treatment. The mortality also became 100% in all treatments of integration applied at all rates, following 12 days of treatment application likewise the positive control. All treatments of integration applied at all rates also induced significantly (P < 0.05) higher (≥ 60.31%) protection of maize grains against F1 progeny emergence, grain damage (≤ 6.67) and weight loss (≤ 1.12) by S. zeamais than negative control. Besides, 100% inhibition of F1 progeny emergence, no percent grain damage and weight loss of maize grains were also observed in all of the three treatments of integration applied at dosage of 10% likewise also for that of the positive control. Therefore, integration of the aforementioned botanicals and inert dusts with resistant varieties applied at 2.5% and above (5 and 10%) rates were potent in preventing maize grains against maize weevils attack and could be used in the management of maize weevils as ecologically sound, safe and cheap weevil's management alternatives under farmer's storage conditions.