Fomes annosus Root and Butt Rot: A Threat in Managed Stands in Coastal British Columbia

In coastal British Columbia stands, airborne spores of Fomes annosus are present throughout most of the year and are particularly numerous during October-November and February-March. Stumps of most commercial conifer species are susceptible to spore infection and the fungus can grow from diseased into healthy roots when in contact. Infection centers in immature stands have originated from mycelium present in stumps of the previous stands. Indications are that Fomes annosus root rot will be a significant problem should thinning become a common forest management practice if steps are not taken to control stump infection. Application of borax is recommended to reduce spore infection of stumps.