Integrated Management of Sweetpotato Weevil (Cylas puncticollis (B.)) (Coleoptera: Curculionidae) at Chano Dorga, Southern Ethiopia
Sweet Potato Weevil (SPW) (Cylas puncticollis) (B.) is a destructive pest of sweet potato in Ethiopia. It causes severe damage to the tuber and infested tuber further produce bitter taste becoming unsuitable for human consumption and animal feed. This problem calls for C. puncticollis effective control measure (s). An experiment was carried out with the aim to identify effective control tools by integrating two cultural practices (Earthing-up and harvesting time). Sweet potato variety, Awassa-83, a moderately resistant variety to C. puncticollis was used for the study. Two factors: Earthing-up with four levels (no, 1x, 2x, 3x and no earthing-up) and harvesting time with three levels (prompt harvesting, one and two months delayed harvesting) making up 12 treatment combinations were tested. These treatment combinations were laid-out in a Randomized Complete Block Design (RCBD) with three replications. Marketable and unmarketable yield (t ha-1), sweet potato damaged tubers, yield loss, percent damage and weevil density were assessed. The result obtained indicated that combination of three times earthing-up and prompt harvesting significantly reduced number of damaged tubers (25 plot-1), SPW density (29.77 plot-1), damage percentage (6.9% plot-1), unmarketable yield (0.56 t h-1) and yield loss (8.68%). These demonstrate the effectiveness of frequent earthing-up and prompt harvesting for management of SPW. Hence, integrated use of resistant variety, prompt harvesting and three times earthing-up can be recommended for the management of SPW in southern Ethiopia.