First Report of Passion Fruit Brown Spot Incited by Alternaria passiflorae in Florida. R. T. McMillan, Jr., Department of Plant Pathology, University of Florida, TREC, Homestead 33031. W. R. Graves, Department of Plant Pathology, University of Florida, TREC, Homestead 33031. Plant Dis. 75:319. Accepted for publication 18 October 1990. Copyright 1991 The American Phytopathological Society. DOI: 10.1094/PD-75-0319D.
Aiternaria passiflorae J.H. Simmonds, the causal agent of brown spot disease on passion fruit (Passiflora edulis Sims), has been found in commercial passion fruit plantings in Dade County, Florida. In the spring of 1990, fruits, vines, and leaves of P. edulis 'Possum Purple' from two commercial growers were found to be infected with an Alternaria sp. subsequently identified by the Commonwealth Mycological Institute, Kew, England, as A. passiflorae. Foliar lesions and sporulation of the fungus resulting from inoculation of P. edulis leaves were identical to those resulting from natural infection. Leaf symptoms start as small brown spots, which expand to 1- 2 cm in diameter, with round to irregular margins and pale brown to gray centers. Lesions on the fruit also begin as small brown spots that expand to 1-2 cm in diameter; the fruit spots are sunken with round or irregular dark margins and pale brown to gray centers. A. passiflorae has been reported in Australia, Canada, Hawaii, Indonesia, Kenya, New Zealand, Papua New Guinea, Tanzania, and Zambia. This appears to be the first occurrence of A. passiflorae reported in the continental United States.