Effectiveness of different storage structures for the management of Mexican bean weevil, Zabrotes subfasciatus (Boheman) (Coleoptera: Bruchidae) on stored common bean, Phaseolus vulgaris L. (Fabaceae)

Abstract

Common bean, Phaseolus vulgaris L. is an important source of protein and plays a crucial role to enhance food and nutrition security in Ethiopia. However, Mexican bean weevil, Zabrotes subfasciatus (Boheman) (Coleoptera: Bruchidae) is a major constraint of stored common bean that leads to quantity and quality losses. In traditional storage structures, the grain storage period was reduced due to storage conditions and insect pest infestation. Laboratory experiments were conducted to evaluate the effectiveness of five different storage containers and structures namely: PICS bag, polyethylene bag, polypropylene bag, jute sack, and Diya (traditional structure) for the management of Z. subfasciatus. Percentage of insect damage, weight loss, and germination were evaluated at the monthly interval while proximate compositions were analyzed at the beginning and end of the storage period. The results indicated that significantly high grain damage, weight loss, and reduction in grain germination were observed in grain stored in farmer's storage facilities as compared to PICS bag.The moisture content of the grains decreased along the storage duration. Crude protein contents significantly decreased as the storage duration increased in all storage types except the PICS bag. A reduction in carbohydrate content was observed in Diya compared to other storage types. The results of this study demonstrated that the PICS bag reduces qualitative and quantitative losses in common beans caused by Z. subfasciatus. Further research should also be carried out on improving Diya, traditional structure.