A Virus Scouting and Vine Rogueing Program in Lodi Vineyards
by Ted Rieger
November 01, 2019
Originally posted on WineBusiness.com
LangeTwins Family Winery & Vineyards in Lodi has implemented a vineyard virus scouting, mapping and vine rogueing program aimed at managing leafroll and red blotch virus infections and preventing their spread. The program, used in newer plantings of red winegrape varieties (planted since about 2013) is modeled after a successful program used in South Africa where vine mealybug (Planococcus ficus) and leafroll viruses have been ongoing management issues in winegrape vineyards.
The Lodi Winegrape Commission (LWC) held a leafroll virus tailgate talk October 17 at a LangeTwins managed vineyard where virus scouting and vine rogueing takes place. Aaron Lange, vineyard operations manager at LangeTwins, provided background, presented case studies and displayed maps and data for specific vineyards where the program is used.
Lange described symptoms and problems associated with the virus of most concern, grapevine leafroll-associated virus 3 (GLRaV-3), that can turn vine canopies red in red grape varieties, reduce yields, and reduce color and anthocyanin content in fruit. He acknowledged that leafroll virus has existed a long time in Lodi and other California vineyards, but said it has become a bigger concern and problem over the past 15 years due to the introduction and spread of the vine mealybug (VMB). “We’ve never had a vector like the VMB that is so efficient at spreading leafroll and is difficult to control--that is a critical point,” he observed. He told growers, “If you don’t think you have viruses or VMBs in your vineyard, you’re not looking hard enough.”
Lange noted the virus management challenges in the Lodi region where vineyards are the dominant crop and numerous landowners and growers are involved. He explained: “We have vineyards everywhere, and managing just your own field is not enough. You have to look across the road at your neighbor and have that delicate conversation about their virus issues and management. It’s not easy, but it’s something we have to do. This has to be a community-wide effort.”
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