Fomes annosus Butt-Rot of Sitka Spruce IV. Observations on the Distribution of Cryptosporiopsis abietina (Petrak) in the Stems of Rotted Trees

Cryptosporiopsis abietina was isolated from the heartwood of 12 out of 18 Sitka spruce suffering from butt rot caused by Fomes annosus , but from none of eight healthy trees from the same plantations. C. abietina was present in a distinct zone above the tissue colonised by F. annosus . It was present in both sound wood, and in wood with stain or incipient decay. C. abietina inhibited the growth of F. annosus on malt agar, and to a lesser extent in autoclaved Sitka spruce heartwood. The possible influence of this potentially antagonistic fungus on infection by F. annosus is briefly discussed.