Improving management of hop powdery mildew

Once the leading producer of hops in the U.S., New York state is making investments to strengthen a re-emerging hops industry, including tax incentives to expand NY’s craft brewing industry. However, powdery mildew – which destroyed the industry in New York state in the early 1900s – remains a threat. We need to increase understanding of pathogen ecology and to find ways to apply this new knowledge to reduce crop loss with less pesticide use.

This project focused on finding ways to better control the destructive disease of powdery mildew through a better understanding of pathogen biology and ecology. The approach was to track for two years the seasonal distribution of ascospore discharge in three locations – New York, Raleigh, NC, and Madison, WI. Samples of hop powdery mildew were collected from all hop growing regions – across the United States and Europe – with an emphasis on collecting samples from commercial and feral plantings of hop. Also, the impact of acute cold events was exhaustively analyzed in the primary way in which an acute cold event could occur and affect the hop powdery mildew pathogen.