POST-HARVEST DEVELOPMENT OF RHIZOCTONIA-SOLANI KUHN ON POTATO-TUBERS

The number of tubers infected by Rhizoctonia solani Kühn, but not the extent of infection, significantly increased when tubers were kept in a commercial bulk store for six months after harvest. Tubers were placed in a small cold store for eight weeks and kept under dry or wet conditions. The numbers infected significantly increased under dry conditions when tubers were harvested immediately after haulm destruction in August or September, but under wet conditions only when tubers were harvested in September. Wounds infected by R. solani could develop into extensive rots during storage particularly in wet conditions. Sclerotia are usually thought to be limited to the tuber surface, but some were found to penetrate the periderm to the cortex; moreover, the depth and extent of penetration could increase during storage. © 1979 Kluwer Academic Publishers.