First Report of Crown Rot (Phytophthora cactorum) of Strawberry in Eastern North America. W. F. Wilcox, Department of Plant Pathology, New York State Agricultural Experiment Station, Cornell University, Geneva 14456. . Plant Dis. 73:183. Accepted for publication 30 November 1988. Copyright 1989 The American Phytopathological Society. DOI: 10.1094/PD-73-0183E.
Wilting and dying strawberry (Fragaria × ananassa Duch. 'Raritan') plants with no symptoms of red stele, yet with variable levels of root necrosis and red-brown, basipetally advancing lesions within the crown, were observed in two fields in Suffolk County (Long Island), New York. Affected plants in one field (third-year fruiting) were concentrated in a low, wet area, whereas those in a newly planted field were distributed randomly. Isolations from necrotic crown tissue onto P5ARP or P5ARPH media (1) consistently yielded Phytophthora cactorum (Leb. & Cohn) Schroet. An isolate from each field caused crown rot, wilt, and collapse of greenhouse-propagated strawberry plants grown for 8 wk at 25 C in pasteurized soil infested with colonized vermiculite inoculum (2%, v/v) and flooded for 48-hr periods at 2-wk intervals. In contrast, two isolates of P. cactorum from apple crowns and one each from a raspberry root and crown caused no disease, supporting the contention that crown rot of strawberry is caused by a distinct pathotype of P. cactorum (2). This is the first report to confirm the occurrence of crown rot (vascular collapse) of strawberry in eastern North America.