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ARS Home » Pacific West Area » Corvallis, Oregon » Forage Seed and Cereal Research Unit » Research » Publications at this Location » Publication #380384

Research Project: Breeding, Genomics, and Integrated Pest Management to Enhance Sustainability of U.S. Hop Production and Competitiveness in Global Markets

Location: Forage Seed and Cereal Research Unit

Title: Management of hop powdery mildew in the context of recent advances in pathogen ecology and population genetics

item WELDON, WILLIAM - Cornell University
item Gent, David - Dave
item GADOURY, DAVID - Cornell University

Submitted to: Plant Health Progress
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/7/2021
Publication Date: 11/7/2021
Citation: Weldon, W.A., Gent, D.H., Gadoury, D.M. 2021. Management of hop powdery mildew in the context of recent advances in pathogen ecology and population genetics. Plant Health Progress. 22(4):450-458.

Interpretive Summary: This article reviews and summarizes recent progress in research and understanding of the biology and ecology of the disease hop powdery mildew and its causal agent, the fungus Podosphaera macularis. We place special attention on new genotyping tools that can enable proactive monitoring of pathogen populations and inform whether new occurrences of the disease may be caused by novel strains of the pathogen and predict pathogen traits important for management. We also discuss recently developed epidemiological models that can serve as the basis for disease warning systems for early season infection of hop resulting from the overwintering stage of the fungus.

Technical Abstract: The recent surge in the craft brewing market has renewed hop production throughout much of the Midwestern and Eastern United States (US), adding an element of locally sourced hops for use by regional breweries. All the while the Pacific Northwest US remains the stronghold of US hop production, supplying hops for breweries all across the world. As the industry has evolved, so too have the challenges associated with managing the major pathogens of hop, especially with respect to Podosphaera macularis the causal agent of hop powdery mildew. Uniquely virulent strains have evolved that can overcome widely deployed host resistance genotypes. Sexually reproducing populations of P. macularis that reside within non-cultivated hop threaten introduction into cultivated hop yards throughout the US. The availability of efficacious chemical control products is constantly changing. All of these factors combine to require disease management programs be as efficient, thorough, and precise as possible. Herein, this review article aims to summarize research progress within the P. macularis pathosystem and synthesize major findings as they relate to disease management, placing special emphasis on recent work that has expanded the molecular tools available to study P. macularis population structure, epidemiological models that describes aspects of pathogen overwintering, and improvements in our understanding of basic pathogen ecology.