Developing hop virus diagnostic tools to support effective diagnosis and clean plant initiatives essential for hop industry growth and sustainability

MSU researcher Carolyn Malmstrom and her team created diagnostic tools for viruses affecting hops in Michigan.

Researcher: Carolyn Malmstrom
Awarded: $39,990
Leveraged: The project leveraged current investments in MSU Plant and Pest Diagnostics and Michigan Department of Agriculture and Rural Development pathogen testing facilities, grower matching funds ($500), and past USDA NIFA investment in virus diagnostics in the Malmstrom Lab.

Hop is a significant emerging crop in Michigan, with considerable existing investments and growth potential. Michigan leads the Midwest in hop production and has the potential to notably expand its production to serve the increasing demand for hops for craft breweries, within and outside of Michigan.

The primary challenge to Michigan’s hop industry has been a lack of clean plant material. Hop plants are vegetatively propagated by propagators and growers through rhizome and shoot cuttings, which leads to the pervasive spread of challenging pathogens, including mildews and viruses. Viruses and viroids are highly prevalent in Michigan hop yards, despite visual inspections, because new yards are frequently started with plants that are not certified virus-free and because infections are often asymptomatic and spread easily.

Viruses and viroids reduce yield, quality and plant longevity, which can substantially impact profitability. The primary cause of this disease problem is a lack of reliable diagnostic tools and regional testing facilities, which has required growers to send samples out of state for testing at considerable cost for both tests and shipping.

For this project, researchers developed and validated protocols for diagnosing hop virus and viroid infections, and distributed that information to growers across Michigan. This work is being conducted through the MSU Plant & Pest Diagnostic Lab.

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