A Decade of Hop Powdery Mildew in the Pacific Northwest

Hop powdery mildew, caused by the fungus Podosphaera macularis, was confirmed for the first time in hop yards in the United States Pacific Northwest in 1997. The US hop industry experienced significantly crop loss and damage from the disease, but new knowledge, grower experience, and management approaches have allowed the industry to survive the introduction of this damaging pathogen. This review provides an overview of research on and progress towards economically sustainable management of hop powdery mildew in the US, and future directions for research and further innovation. Accepted for publication 2 January 2008. Published 14 March 2008.