Disease Note

Nectria galligena Causing European Canker of Apple Trees in Ontario. A. R. Biggs, Agriculture Canada Research Station, Vineland Station, Ontario L0R 2E0. Plant Dis. 69:1007. Accepted for publication 19 July 1985. Copyright 1985 The American Phytopathological Society. DOI: 10.1094/PD-69-1007f.

European canker of apple (Malus domestica Borkh. ‘MacIntosh’) caused by Nectria galligena Bres. was first observed in Wentworth County, Ontario, Canada, in March 1985. The fungus had been present for at least 5 yr. Target-shaped perennial cankers associated with pruning wounds were found bearing red perithecia that contained mature, clavate asci 76.2–89.5 μm long (av. 82.5 μm) and smooth, hyaline, two-celled ascospores (av. 21.2×7.5 μm). Cankers initiated the previous year had cream-colored sporodochia with microconidia and macroconidia similar to those described for Cylindrocarpon mali (Allesch.) Wr. These descriptions correspond to those for N. galligena. The disease was limited to one orchard where approximately 20% of the trees were infected. The geographic range of this fungus in Canada now includes the apple-growing region of central Ontario.