A Touch Of The Grape

I got a really good e-mail today. The title was: Group Formed To Stop Grape Malady. It had to do with Pierce's Disease. The gist of the e-mail was to let winegrowers in California know that a referendum was coming up. It read: "The steering committee aims to convince growers to again vote “yes” for the Pierce's Disease/Glassy-winged Sharpshooter Referendum to continue the industry’s self-assessment to fund research working toward a permanent solution to the deadly Pierce’s disease virus". “Having effectively contained the spread of the disease and vector for over a decade, the control program is recognized as one of agriculture’s most remarkable successes".
If you have NO IDEA what this all means, I will fill you in.


Photo courtesy of UC Davis

PIERCE'S DISEASE is a vine infection by the bacterium Xyella fastidiosa. It is introduced by insects, The Glassy-Winged Sharpshooter or Leafhoppers, (Cicadellidae) they feed on vine sap by puncturing vine stems and shoots. The bacteria multiply inside the plant and eventually block the flow of water and nutrients, debilitating the vine's metabolic functions, reducing the crop and killing the vine in the worst cases within three to five years of infection. The insects move from vine to vine, spreading the disease throughout vineyards and regions and causing millions of dollars in damage.
The disease is native to the Southeast of North America and thrives especially in warm, humid areas. It is known to be present from California to Florida and south as far as Central America. This is why it is hard to grow many varieties of Grapes in South Carolina or in many other places in the Southeast. Native Muscadine grapes are resistant.
A little history about it. A researcher first discovered it in 1892 and called it Anaheim disease; it also affects almonds and alfalfa and the name was later changed, reflecting the name of its discoverer, Pierce. Since there has been no cure, it is one of the principal reasons that cuttings of grapevines and other plants are quarantined in moving between countries.
I have been growing Concord Grapes for 3 or 4 years now. The disease finally took two of my vines. I am hoping that the third and final vine will give me one more year at least. I have a couple of other varieties of grapes rooted in the wings to take over. Hopefully they will produce for a few years. According to Clemson Extension you can grow Grapes here, Special varieties should be grown in order for the vineyard to live for more than three years however. So I guess the search is on to find some varieties that are immune or at least somewhat resistant. Maybe I will have hit the jackpot with what I have rooted. I WILL miss my Concord's though. They made some really good jelly the past couple of years. I hope the referendum passes and someday they find some kind of cure for this. I want to be able to enjoy my homemade Concord Grape Jelly again!
Happy Growing!
Darren