Pinicola brown crumbly rot

Fruiting bodies of the fungus André Carpentier

French disease name: Carie brune cubique
Pathogen name: Fomitopsis pinicola (Sw.:Fr.) P. Karst.
Kingdom: Fungi
Phylum: Basidiomycota
Class: Agaricomycetes
Order: Polyporales
Family: Fomitopsidaceae
Partial list of synonyms:
- Fomes pinicola (Sw.: Fr.) Cooke

Distribution

Canada

Damage, symptoms and biology

The fungus can cause heart rot in living trees but it is mainly involved in decomposing the wood of trees that have been killed by other pathogens. Infection generally begins in an existing wound on the tree. Since the fungus mainly colonizes dead matter, there may be many pockets of infection. A pale yellow to brownish discoloration of the wood is the earliest sign of infection. Later the decayed wood breaks into small cubes and takes on a brown or reddish colour. Red fruiting bodies appear around the infected areas, forming wide strips. The young fruiting bodies produce spores all season long, which are dispersed in wet weather. Over time, the fruiting bodies turn grey and wrinkled, and the underlying wood dries out and turns light brown in colour.

Other information

Fomitopsis pinicola is one the most damaging decay fungi in old-growth forests. It is a less serious problem in second-growth stands, but infected dead trees are subject to windthrow and top-breakage, making them high-risk hazard trees.

The infection risk for healthy trees can be reduced considerably by removing dead trees infected with brown cubical rot.