UC Davis to Build New $5.25 Million Greenhouse to Protect U.S. Vineyard Collection

A new greenhouse at UC Davis will be built to protect the vines from diseases such as red spot disease, which can cause leaves to redden, impede fruit ripening and reduce wine quality. Photo courtesy of Foundation Plant Services/UC Davis

Project designed to prevent red spot and other vine diseases

A new $5.25 million greenhouse is being built on the campus of the University of California, Davis to protect an important collection of vines from red spot disease and other pathogens.

The 14,400 square foot greenhouse will have a vestibule entrance, be insect proof and provide another level of disease protection. It is run by Foundation Plant Services, or FPS, which provides the U.S. wine industry with high-quality, virus-tested vine planting material.

The program is the primary source of vine planting material distributed to nurseries through the California Department of Agriculture's Vine Registration and Certification Program, which supplies the majority of vines planted in the United States. United. For viticulture, it is essential to protect this material from disease-carrying insects and to guarantee rapid access to clean plant material.

“The program is considered the largest quarantine facility for the grapevine industry in the United States,” said Maher Al Rwahnih, plant pathologist and director of FPS. "It's kind of a game-changer for us."

A story at the service of the vine industry

FPS has maintained healthy vine plants on the UC Davis campus for over 70 years in open fields at Classic Foundation and Russell Ranch vineyards. FPS scientists first detected grapevine red spot virus at Russell Ranch in 2017. In 2021, an estimated 51.6% of the crop was infected there. Material from this vineyard is not sold and the site is now part of an epidemiological study to try to determine how the disease is transmitted.

FPS pathologists detected red spots on less than 1% of the Classic Vineyard crop. But it may not always be so in the future.

"We don't know how long the Classic vineyard will stay clean," said Al Rwahnih. "Every testing season, this is what keeps me awake at night. We don't know why this happens at the Russell Ranch and not at the Classic Vineyard."

Once the greenhouse is in operation, vines propagated from Classic Vineyard plant material will be moved into the greenhouse, tested and verified as disease free. From there, it will be sold to nurseries, who will grow additional plants to sell to growers.

Two greenhouses as part of the plan

Normally, the foundation has 4,000 vines available, but the greenhouse will only house 2,000 vines, so the inventory will be halved.

“This phase is just a start-up phase,” Al Rwahnih said. "It's not enough for our needs."

FPS plans to build another greenhouse in the next two to three years to increase capacity.

Industry groups and the FPS have identified greenhouses as the best way to protect plants against red spot and other insect-borne pathogens. They also consult with these same people on which grape varieties to include in the greenhouse.

"We have a wide selection, and we need to make sure that all the varieties important to the industry are contained," he said.

The first greenhouse is expected to be completed by the end of 2023.

Funding for the first greenhouse came from a variety of sources. The California Fruit Tree, Nut Tree and Grapevine Improvement Advisory Board, operated by the California Department of Food and Agriculture, contributed $4 million to the project. The California Grape Rootstock Research Foundation gave $500,000, Foundation Plant Services with UC Davis is funding $450,000, and the California Grape Rootstock Commission gave $100,000.

"This is crucial for the grapevine industry, and we are very grateful for the support," said Al Rwahnih.

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