First Report of Purple Spot (Stemphylium vesicarium) of Asparagus in Washington. D. A. Johnson, Washington State University, Prosser 99350. J. D. Lunden, Washington State University, Prosser 99350. Plant Dis. 68:1099. Accepted for publication 14 September 1984. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/PD-68-1099d.
Stemphylium vesicarium (Wallr.) Simmons was isolated from purple spots on asparagus (Asparagus officinalis L.) spears during harvest and from tan to brown lesions with reddish to dark purple margins on asparagus stems, branches, and cladophylls of fully expanded ferns later in the season. These symptoms have been observed in eastern Washington since 1982. Foliage of potted asparagus plants of five cultivars was wounded with air-blown sand; wounded, then inoculated with a conidial suspension of S. vesicarium; inoculated only; or not wounded or inoculated. Plants were then placed in a moist chamber for 24 hr. Numerous spots as described developed on stems, branches, and cladophylls of plants wounded, then inoculated. Occasional spots appeared on plants inoculated only; no spots appeared on plants in the other treatments. S. vesicarium was reisolated from the spots.