2018 ASHS Annual Conference

Sweetpotato is an important staple food crop in Hawaii, both for local consumption and export. Insect damage, especially from weevils, is a major production constraint of sweetpotato in the state of Hawaii. Rough sweetpotato weevil is an invasive pest recently detected in the Hawaiian Islands. The immature stages of the weevil gouge shallow groves on the surfaces of the storage roots that adversely affect its appearance, reduce its marketability, and result in wounds that could allow secondary microbial infections. Sustainable pest management practices are limited for this pest, due to its recent introduction in these areas. As an interim approach, efficacy of four insecticides including one bio insecticide were compared against a control to manage this pest in the field. Results from two replicated trials indicate that broad spectrum insecticides such as Belay and Carbaryl are effective in managing this pest. Bio insecticide Beauveria bassiana was not very effective at the tested rate. Planting sweetpotatoes continuously in the same area would likely increase pest pressure in subsequent crop cycles because of the buildup of populations in the field. Cultural practices such as crop rotation and use of clean planting materials should help to reduce the incidence of pests in the field.