Disease Note

Fruit Rot of Pumpkin in Arkansas Caused by Fusarium equiseti. J. C. Correll, Department of Plant Pathology, University of Arkansas, Fayetteville 72701. J. K. Mitchell, and C. R. Andersen. Department of Plant Pathology, and Department of Forestry and Horticulture, University of Arkansas, Fayetteville 72701. Plant Dis. 75:751. Accepted for publication 21 February 1991. Copyright 1991 The American Phytopathological Society. DOI: 10.1094/PD-75-0751A.

A fruit rot of pumpkin (Cucubita pepo L) hu been observed periodically in Arkansas. In 1990, a 1-ha field of pumpkin cv. Halloween had a bigh incidence of fruit rot; losses were estimated to be 3O%. Initial symptoms included soft, sunken area on the fruit. Lesions often became water-soaked, and mycelium was observed frequently on the fruit surface. Lesions did not always occur on the part of the pumpkin in contact with the soil and were not associated with obvious wounds. Extensively colonized fruit collapsed completely. Symptnms did not develop in some fruit until after harvest. Fusarium eqiseti (Corda) Sacco was consistently isolated from Iymptomatic fruit. Koch's postulates were completed with two pumpkin isolates of F. equiseti on detached mature fruit of cv. Small Sugar in a growth chamber at 32 C. Wounds were neoeuary for invasion and colonization of the fruit. Soft, sunken, water-soaked lesions, similar to field symptoms, developed within 30 days. Symptom development of individual fruit varied considcrably. Although all inoculated wounds resulted in extensive colonization (as determined by vuible mycelium and/or reisolation), not all inoculated wounds resulted in soft, sunken, water-soaked lesions. This is the first report of F. equiseti causing fruit rot of pumpkin.