The University of California, Davis, (UC Davis) will soon release five new Pierce’s Disease resistant grapevine varieties through the work of renowned viticulture professor and geneticist Dr. Andy Walker. The release includes three red wine grape varieties and two white wine grape varieties. These new grape varieties were developed to contain a high percentage, as much as 97%, Vitis vinifera parentage. The varieties contain Pierce’s Disease resistant genes from Native American Vitis species.
UC Davis will begin to market and license these new varieties once the notice of US Patent filing is complete. Wonderful Nurseries, NovaVine, and Sunridge nurseries are in the process of obtaining licenses for these new PD resistant varieties.
Pierce’s Disease is a grapevine disease that is caused by the bacterium Xylella fastidiosa. The bacterium is spread by insects known as sharpshooters. While prevalent through many parts of the United States, the disease pressure from PD is particularly strong in hot climates. Pierce’s Disease can be devastating to vineyards, potentially causing total loss of vines over the course of a few years. PD is one of the driving reasons we don’t see a lot of Vitis vinifera grown in the Texas Gulf Coast. Pierce’s Disease can also be problematic in the Texas Hill Country.
I reached out to Frances Pontasch, Extension Program Viticulture Specialist at the Texas A&M AgriLife Horticulture Extension, to get her thoughts on this potentially important development for the Texas wine industry.
TWL: What do you think are the biggest opportunities for Texas vineyards and wineries with the new Walker PD varieties?
Fran: Not being able to produce V. vinifera is a big disappointment for most high PD zone grape growers. So, of course, the biggest opportunity is having V. vinifera choices of winegrapes to plant and wines to make without worry of losing the vines to Pierce’s Disease.
TWL: What do you think the biggest challenges will be for Texas vineyards and wineries to be successful with the new Walker PD varieties?
Fran: The biggest challenge is for growers who grow but do not make the wine, because marketability of the crop is unknown. Will wineries purchase Walker grapes in quantity? Other challenges to the new varieties is that they are still susceptible to our numerous fungal diseases, with the addition of being susceptible to powdery mildew. And, canopy management differs. Canopy affects yield more in hybrids than in vinifera while canopy affects wine quality in vinifera more than hybrids.
The five new PD resistant grape varieties are:
Camminare Noir (07355-075) – Red wine grape with 50% Petite Sirah and 25% Cabernet Sauvignon parentage
Paseante Noir (09331-047) – Red wine grape with 50% Zinfandel, 25% Petite Sirah, and 12.5% Cabernet Sauvignon parentage
Errante Noir (09356-235) – Red wine grape with 50% Sylvaner, 12.5% Cabernet Sauvignon, 12.5% Carignane, and 12.5% Chardonnay parentage
Ambulo Blanc (09314-102) – White wine grape with 62.5% Cabernet Sauvignon, 12.5% Carignane, 12.5% and Chardonnay parentage
Caminante Blanc (09338-016) – White wine grape with 62.5% Cabernet Sauvignon, 12.5% Chardonnay, and 12.5% Carignane parentage
Earlier this year I attended the Gulf Coast Grape Growers Field Day in Cat Spring, TX, where Jim Kamas and Brianna Hoge shared info about their research trials with some of the Andy Walker PD resistant vines. While trials are early, there does seem to be potential with these newly released varieties, particularly Camminare Noir. More research is underway, providing another way to show that these are exciting times in the Texas wine industry.
If you would like to learn more about these new grape varieties, UC Davis has more information on their website. If you would like to learn more about growing grapes in the Texas Gulf Coast, the 28th Annual Gulf Coast Field Day will take place on February 7th, 2020 at the historic Cat Spring Agricultural Society Hall.