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ARS Home » Pacific West Area » Corvallis, Oregon » Forage Seed and Cereal Research Unit » Research » Publications at this Location » Publication #430175
Research Project: Development of Superior Hops and Resilient Hop Production Systems

Location: Forage Seed and Cereal Research Unit

Title: Evaluation of fungicides for hop downy mildew, Hubbard, Oregon, 2025

Author
item MASSIE, STEPHEN - Washington Hop Commission
item RICHARDSON, BRIANA - Oregon State University
item Gent, David

Submitted to: Plant Health Progress
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/13/2026
Publication Date: 3/19/2026
Citation: Massie, S.T., Richardson, B.J., Gent, D.H. 2026. Evaluation of fungicides for hop downy mildew, Hubbard, Oregon, 2025. Plant Health Progress. 27(2):345. https://doi.org/10.1094/PHP-11-25-0262-PDMR.
DOI: https://doi.org/10.1094/PHP-11-25-0262-PDMR

Interpretive Summary: Hop growers in the western U.S. must contend with the disease downy mildew. Crop protection tools are, at present, important for maintaining crop yield and quality because most cultivars are susceptible to the disease at some level. In this study, we evaluated various synthetic and non-synthetic alternatives for management of downy mildew. This information is part of a long-term effort to identify diverse reduced-risk fungicides and fungicide alternatives that can sustain disease management and hop production.

Technical Abstract: Hop downy mildew, caused by Pseudoperonospora humuli, is a widespread and damaging disease of hop in many production regions worldwide. This report summaries the efficacy of synthetic and biological fungicides in the suppression of hop shoots with systemic downy mildew in the cultivar ‘Nugget’ in a trial conducted near Hubbard, Oregon, in 2025. Findings from this trial will help inform management of the disease and support future analyses that can mitigate crop damage and minimize use of ineffective or unnecessary