Relative Aggressiveness of Fusarium Dry Rot Pathogens on Seven Potato Varieties

Abstract Fusarium dry rot is a tuber decay potato disease that occurs worldwide in the field and in storage. This study investigated the relative aggressiveness of Pacific Northwest (United States) isolates of dry rot pathogens on seven potato varieties. Tubers were challenged with seventeen isolates across four pathogenic species of Fusarium in a controlled environment. The interaction of potato variety and Fusarium species was significant, with the most severe dry rot lesions observed for the combinations of Fusarium sambucinum on Umatilla Russet, Russet Burbank, or Atlantic, and Fusarium oxysporum on Dark Red Norland. In contrast, Fusarium redolens and Fusarium culmorum were least aggressive on all varieties. Variation in aggressiveness within species was observed for F. sambucinum . These data highlight the importance of identifying the species causing Fusarium dry rot and suggest that variety selection may play a role in alleviating the disease.