The New York State Department of Agriculture and Markets (AGM), in partnership with Cornell AgriTech, has launched a revitalized grapevine certification program to provide growers in New York and North America with clean, virus-tested plant material verified by the most stringent testing standards in the world.

Three New York nurseries are participating in the voluntary program and offering certified vines to growers in the U.S. and Canada. New York-certified grapevines from these nurseries are verified as free of nine viruses that cause significant economic losses to vineyards across New York and North America.

Grapevines, like humans, can be infected by multiple viruses. But there are no vaccines (or chemical sprays) for grapevine viruses, and no genes or groups of genes have been found in wild or cultivated grape species that confer stable virus resistance. Unless removed from the vineyard, infected vines spread disease to healthy ones, shortening a vineyard’s productive lifespan by up to 75% and causing delayed ripening, poor fruit quality and 30% to 80% reductions in yield.

“The only effective way to deal with viruses in vineyards is prevention,” said Marc Fuchs, professor of plant pathology and plant-microbe biology at Cornell AgriTech. “Using clean, virus-tested planting stocks is the key to reducing the presence of viruses in newly established vineyards and lessening their detrimental impact on New York growers.”

New York’s new virus-tested certification program is the product of a 15-year collaboration driven by the three primary grapevine nurseries in the state—Amberg Grapevines in Clifton Springs; Double A Vineyards in Fredonia; and Hermann J. Wiemer Vineyard in Dundee. New York grape growers and the nurseries brought in Fuchs, Cornell AgriTech and the AGM not just to reestablish an earlier program discontinued in the 1980s, but to create something new and innovative.

“This certification program is critical to the economic well-being of grape growers in New York state,” said Richard Ball, commissioner of agriculture for the AGM. “We’re proud to partner with Cornell AgriTech, whose expertise in using the latest technology allows us to detect, with extreme accuracy and in a short amount of time, viruses in grapevines, helping protect our $6.65 billion wine and grape industry.”

According to Fuchs, the testing frequency and aggressiveness of New York’s certification program is now the highest in the U.S. or abroad. First, nurseries establish increase blocks using virus-tested plant material from foundation vineyards managed by the USDA’s National Clean Plant Network. Cuttings from these mother blocks are used for grafting and propagating certified nursery stock.

Each year, state horticulture inspectors sample 25% of increase block vines (scion and rootstocks) in the spring and fall and submit them blind to Fuchs’ lab for testing; after four years, 100% of vines have been tested. Inspectors also visually double-check certified nursery blocks twice per season. If something looks off, they sample and test.

Currently, Fuchs’ lab tests for nine viruses economically relevant to New York growers: grapevine fanleaf virus, tomato ringspot virus, tobacco ringspot virus, arabis mosaic virus, grapevine leafroll-associated viruses 1-4; and grapevine red blotch virus. Using the latest virus-screening technologies, his team has shortened the turnaround time for test results from years to weeks or days. And if new problematic viruses emerge, AGM has a streamlined process for making protocol changes.

Margaret Kelly, assistant director in the Division of Plant Industry at AGM, said this stringent monitoring is essential to catch viruses that may have been introduced into clean material during propagation, and provides the level of insurance growers need.

“Grapevines are perennials,” Kelly said. “You can’t just start over fresh next year. These plants are in the ground for generations, which is why certification is so important.”

Dennis Rak ’80, president of Double A, purchased 80 additional acres and added staff in order to participate in the program. Amberg had land available but is now starting the expensive, labor-intensive process of removing old vineyard to expand its certified blocks. Once nurseries established their increase blocks, the state began collecting and testing up to 100,000 samples annually. Now, each nursery has a limited supply of New York-certified vines, but Kelly says more will become available every year.

Eric Amberg, whose nursery sells a significant amount to out of state customers, says that having a virus-tested certified option is becoming an increasingly important aspect of purchasing for growers, especially those east of the Rocky Mountains. Canada also recently recognized the New York certification program so growers there can import certified vines, opening a nearby market that’s been clamoring for high-quality planting material for years.

“When I look at our demand for and sales of clean plant material now, I can’t imagine where we’d be if we hadn’t decided to participate,” Rak said. “Our customers are happier and we’re excited for the future.”

Funding for this program was provided from the New York State Environmental Protection Fund, the USDA APHIS Farm Bill and the New York Wine and Grape Foundation.       

Sarah Thompson is a writer for Cornell AgriTech.