Seasonal Variation of Stump Infection by Fomes Annosus in Coastal British Columbia

Abstract

Susceptibility of fresh-cut stumps of western hemlock, amabilis fir, Douglas-fir and Sitka spruce to infection via Fomes annosus (Fr.) Karst. spores was determined at 12 consecutive monthly intervals. Over 40% of the amabilis fir, western hemlock, Douglas-fir and Sitka spruce stumps became infected throughout the year when inoculated with a basidiospore suspension. Airborne spore infection of amabilis fir was high (> 80%) throughout the year; infection of Douglas-fir was lower during the summer, whereas infection of hemlock was lower during the fall and winter. Excepting amabilis fir, natural airborne spore inoculum resulted in a lower percentage stump infection than when the stumps were inoculated with basidiospores.