Whether they are grown for wine, raisins or the table, grapes are one of the most important crops in the U.S., with a value of more than $5 billion. But they are threatened by a fast-adapting fungus that is developing resistance to common, effective control products, leaving growers vulnerable to crop loss.
To keep grapes affordable and environmentally sustainable, researchers at Washington State University and partnering institutions are launching a four-year, $4.75 million project aimed to reduce fungal resistance to low-cost, pest-specific controls, ensuring we can keep enjoying grapes and wine.
Race against disease
Cracking grape berries and covering leaves in white, powdery mildew is the bane of grape growers nearly every year, costing millions nationally to manage and driving up the cost of production.
For years, U.S. grape growers have relied on inexpensive, effective treatments to protect their crop from the disease. But powdery mildew is developing resistance to common controls, putting the future of sustainable grape production in jeopardy.
“Just like in human health, pathogens adapt and become resistant to the chemicals we use to control them,” said Michelle Moyer, viticulture Extension specialist at WSU. “When that happens, the treatments we’ve relied on to prevent infection no longer work.”
This fall, Moyer leads a new, national effort to reduce the impact of resistance, titled “FRAME: Fungicide Resistance Assessment, Mitigation and Extension Network for Wine, Table and Raisin Grapes.”
Funded by the U.S. Department of Agriculture’s Specialty Crop Research Initiative and led by researchers at WSU and the USDA Agricultural Research Service, the project will improve how we detect and predict resistance, and develop strategies that help growers, Extension educators and manufacturers reduce the economic impact of resistance.
“With FRAME, we have a chance to tackle resistance before it becomes a larger problem,” Moyer said.
Preserving the best defense
Growers and scientists around the world have seen the steady emergence of mildew populations that resist targeted, inexpensive chemicals. Without them, growers are forced to use harsher, broad-spectrum treatments more often, or risk losing their crop entirely.
By understanding how mildew develops resistance and how that mildew spreads, FRAME will help the grape industry balance economical, environmentally-friendly practices with their disease management goals.
Developing a network of experts and a community of knowledge, molecular biologists on the team will create better, faster tests for resistance, while Extension specialists set up service centers across the U.S. to put those tests into practice.
FRAME engineers will model resistance hotspots using local weather and topography, while viticulturists and field pathologists will test management strategies in the vineyard. At the same time, economists will research ways to encourage farmers and distributors to use spray practices that prevent resistance.
Going beyond grapes
“Resistance doesn’t just affect grapes and powdery mildew,” says Moyer. That’s why, once the process is established, the FRAME concept could be expanded to many specialty crops, from apples and cherries to hops and potatoes, improving a wide swath of the food supply.
“The end result means more effective use of the tools we have for disease management, sustainable grape production, and ultimately, more affordable wine, table and raisin grapes for consumers,” Moyer said.
Preliminary data for FRAME was funded by the American Vineyard Foundation, the Oregon Wine Board, and the Washington State Grape and Wine Research Program.
- For a full list of team members and details about the grant, visit the NIFA grant website. Find news and updates on the FRAME Network here.