Canadian Forest Service Publications
First report of powdery mildew on Gaultheria shallon in Canada. 2006. Zhao, S.; Shamoun, S.F. Canadian Journal of Plant Pathology 28: 313-316.
Issued by: Pacific Forestry Centre
Catalog ID: 26549
Salal (Gaultheria shallon) is an economically important plant on the west coast of British Columbia, Canada. Symptoms of infection with powdery mildew were observed on salal leaves, petioles, young twigs, racemes, bracts, and calyces. Pathogenicity tests showed that this pathogen can infect salal within a broad range of temperature (12–25 °C) and relative-humidity (25%–100%) conditions, causing leaf chlorosis and distortion, death of small twigs, and consequently, growth inhibition of seedlings. Detailed description and illustrations suggest that this fungus represents a new record of an Erysiphe sp. in British Columbia, Canada. This species differs from Erysiphe (Microsphaera) vaccinii or Erysiphe (Microsphaera) penicillata s. l. by its appendages and flexuous conidiophore foot cells. Erysiphe vaccinii and E. penicillata were reported as pathogens causing powdery mildew on salal in the United States of America. On the basis of its conidial and conidiophore features, this fungus could be placed into the revised anamorph taxon Oidium subg. Pseudoidium (teleomorph: Erysiphe emend. Braun).