Fusarium Fruit Rot of Pumpkin in Connecticut

In 1992, an unusual array of symptoms was found in Connecticut exclusively on cultivar Howden pumpkins (Cucurbita pepo). The lesions decreased marketability of the pumpkins and were categorized as a preharvest dry, hard rot (type 1) or a postharvest soft, sunken rot (type 2). In decreasing frequency of isolation, Fusarium acuminatum, F. equiseti, and F. graminearum were isolated from type 1 lesions, and F. graminearum, F. equiseti, F. avenaceum, and F. solani were recovered from type 2 lesions. When isolates of each species were wound-inoculated into mature pumpkins representing 13 cultivars of C. pepo, they all produced type 2 lesions except F. acuminatum, which produced type 1 lesions. The cultivar Atlantic Giant (Cucurbita maxima) was resistant to colonization by all Fusarium spp. tested. There was no effective inhibition of hyphal growth or spore germination of F. acuminatum, F. equiseti, and F. graminearum from eight fungicides tested in vitro.