ARS | Publication request: Powdery mildews on weeds in the Pacific Northwest: a miscellany of new records

Submitted to: Pacific Northwest Fungi
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 11, 2006
Publication Date: January 5, 2007
Repository URL: http://hdl.handle.net/10113/18551
Citation: Dugan, F.M., Glawe, D.A. 2007. Powdery mildews on weeds in the Pacific Northwest: a miscellany of new records. Pacific Northwest Fungi. 2(1):1-7. DOI: 10.2509/pnwf.2007.002.001

Interpretive Summary: Several new records are presented for species of powdery mildew (a type of obligately parasitic fungus) documented on weedy plants in the Pacific Northwest. One of these powdery mildews has been viewed as a potential biological control agent on its host (Canada thistle) whereas some others are better known as pathogens of agronomic crops in addition to weeds. Photographs document useful characters for identification, and changes in nomenclature are summarized.

Technical Abstract: Erysiphye polygoni on Rumex crispus, documented previously in California, is reported for the first time in the Pacific Northwest. Podosphaera (Sphaerotheca) fusca is reported in the Pacific Northwest for the first time on Taraxacum laevigatum, a host record documented previously in Europe. New host records for Idaho are Golovinomyces sordidus on Plantago major, Erysiphe convolvuli on Convolulus arvensus, and Podosphaera (Sphaerotheca) aphanis on Geum macrophyllum. Golovinomyces (Erysiphe) cichoracearum on Cirsium arvense is reported for the first time in Washington.