Sudden Wilt of Passionfruit in Southern Florida Caused by Nectria haematococca. R. C. Ploetz, University of Florida, Institute of Food and Agricultural Science, Tropical Research and Education Center, 18905 S.W. 280th Street, Homestead 33031. Plant Dis. 75:1071-1073. Accepted for publication 16 May 1991. Copyright 1991 The American Phytopathological Society. DOI: 10.1094/PD-75-1071.

A sudden wilt of Possum Purple passionfruit (Passiflora edulis × P. edulis f. flavicarpa) has been recognized for about 5 yr in southern Florida. Results from artificial inoculation studies indicate that a collar rot and canker disease, incited by homothallic strains of Nectria haematococca (anamorph: Fusarium solani), causes sudden wilt. Monoconidial strains of the fungus always caused cankers on wounded vines but did so inconsistently on nonwounded vines. When vines were not wounded, canker development was greater on younger than on older vines. Artificially infected plants supported large cankers without wilting, defoliation, or growth reduction. Reductions in vine growth and vine mortality occurred only after stems became completely girdled. The pathogen was recovered from necrotic and apparently healthy roots and from symptomless vine tissue, from both rooted cuttings from a commercial nursery and from tissue distal to cankers on naturally and artificially infected vines. Thus, it is possible that cuttings taken from latently infected vines may perpetuate the disease. This is the first detailed report of Nectria canker in the Western Hemisphere.