Incidence of Cryphonectria parasitica Cankers on Scarlet Oak (Quercus coccinea) in Pennsylvania. MARY L. TORSELLO, Department of Plant Pathology, The Pennsylvania State University, 210 Buckhout Laboratory, University Park 16802. DONALD D. DAVIS, and BRUCE L. NASH, Department of Plant Pathology, The Pennsylvania State University, 210 Buckhout Laboratory, University Park 16802. Plant Dis. 78: 313-315. Accepted for publication 1 November 1993. Copyright 1994 The American Phytopathological Society. DOI: 10.1094/PD-78-0313.

Surveys were conducted in Pennsylvania during 1989 and 1990 to determine the distribution and incidence of Cryphonectria parasitica (= Endothia parasitica) cankers on scarlet oak (Quercus coccinea). Cankered scarlet oak were found throughout the natural range, with incidence levels (15.0%) comparable to those previously reported in North Carolina (13.8%). C. parasitica was recovered from 69.7% of attempted isolations. Macroscopic signs (pycnidia or stroma) of C. parasitica were associated with 67% of typical cankers. This represents a significant source of inoculum that may serve to further infect scarlet oaks and also American chestnut sprouts. This is the first report of C. parasitica cankers on scarlet oak in Pennsylvania.

Keyword(s): chestnut blight