A Technical Report from The Bartlett Tree Research Laboratories 217
Cankers develop after trees are attacked by a wide range of fungi from the Ascomycetes, Deuteromycetes, Basidiomycetes, and, less commonly, Oomycetes. Generally, stem cankers are caused by Ascomycetes, Deuteromycetes, and Oomycetes, whereas canker rots are caused by Basidiomycetes. Most fungi that cause stem cankers are restricted to bark and xylem tissues that breakdown due to the effects of toxins or secreted enzymes. Such fungi include Nectria galligena, Cryphonectria parasitica, Leucostoma persoonii).