Survey and efficacy test of selected botanical pesticides to manage maize weevil at Gauradaha, Jhapa, Nepal

Abstract

This study was carried out in eastern terai-Gauradaha municipality, Jhapa-of Nepal to evaluate the effectiveness of locally available botanicals for managing the maize weevil (Sitophilus zeamais). Lab experiment was set up in Completely Randomized Design (CRD) with 7 treatments and 3 replications. Six botanicals such as Acorus calamus, Azadirachta indica, Melia azedarach, Artemisia vulgaris, Eucalyptus globulus and Curcuma longa were compared with the control. The botanicals were used in dust forms at the rate of 2g/200g of maize grains. Maize grains were infested with Sitophilus zeamais at the rate of 20 adults/200g. In preference analysis, 66% farmers preferred the use of botanicals, 12% preferred using chemicals and 22% preferred both. On the 28 days of treatment, the highest mortality of maize weevil recorded was 100% in A. calamus and the lowest mortality of maize weevil recorded was 45% in control. Grain damage and weight loss were recorded significantly highest (17.15% and 24.33%, respectively) in control and lowest (0% and 0%) in A. calamus. Also, 100% weevil mortality was observed in A. calamus within 7 days, making it the most effective. Turmeric followed closely with 85% mortality within 28 days followed by chinaberry (78.33%) and neem (75%) during the study. Therefore, varied concentrations of these botanicals can be used to find out effective dose for the management of weevil and further suggests farmers to use recommended dose of botanical pesticides.