Submitted to: Plant Disease Management Reports
Publication Type: Other
Publication Acceptance Date: 1/20/2017
Publication Date: 3/7/2017
Citation: Gent, D.H. 2017. Evaluation of fungicides for hop downy mildew, Woodburn, Oregon, 2016. Plant Disease Management Reports. 11:V047.
Interpretive Summary: Downy mildew is an important disease of hop. This research was conducted to quantify the degree of control of the disease with an industry-standard fungicide that is known to have developed some level of insensitivity over time and also to identify potential alternatives. Under low disease pressure, multiple fungicides with unique modes of action suppressed the disease whereas the industry standard did not. Where resistance to certain fungicides is present, effective alternatives appear to exist.
Technical Abstract: This research was conducted to quantify the degree of control of the disease downy mildew with a phosphorous acid-based fungicide, the present industry-standard for management of downy mildew on hop in the Pacific Northwestern U.S. No suppression of the disease was observed with the industry standard fungicide, whereas all other fungicides with different modes of action provided some control.