First report of powdery mildew of Lactuca sativa (garden lettuce) caused by Golovinomyces cichoracearum in the Pacific Northwest

摘要

During continuing surveys for powdery mildew fungi in the Pacific Northwest,? Golovinomyces cichoracearum ?was found on? Lactuca sativa? (garden lettuce) in Seattle, King County, Washington. This paper documents the occurrence of? G. cichoracearum? on? L. sativa in the Pacific Northwest with illustrations of the fungus from fresh material.