Control of storage insects as a means of limiting yam tuber fungal rots

Yam rots caused by fungal pathogens (mostly Fusarium spp.) are a major caus e of storage losses, and previous work has shown that fungal lesions were o nly found if there was pre-existing physical damage to the tuber. The gener al perception is that damage inflicted in the field prior to storage is far more important in this regard than damage caused during storage, and this has led to much research directed at the minimisation of field damage with relatively little work on the amelioration of insect damage during storage. This study examined whether insect damage inflicted on yam tubers during s torage in specialised barns is an important agent in the incidence of funga l disease. It was found that treatment of tubers with insecticide dust (Act ellic 2% Dust; ai = pirimiphos-methyl) significantly reduced fungal infecti ons resulting from insect attack during storage. In addition, physical dama ge acquired during harvest appeared to be ameliorated by the insecticide, r esulting in significantly fewer fungal lesions. The results suggest that in secticide treatment of yam tubers prior to storage could provide a relative ly cheap and effective means of preservation. (C) 2000 Elsevier Science Ltd . All rights reserved.