On the Watch for Pierce’s Disease

Nationally known viticulturists to share plans to stop spread of grape disease

Table and Chamrbourcin wine grapers are grown at Southwest Research Center near Mt. Vernon, Mo.

More than a century ago, Missouri was second in the country in wine production. But Prohibition took its toll on dozens of vineyards, breweries and distilleries in the state. In the last decade though, wines from the Show-Me State are making a resurgence and putting Midwest grapes back on the map.

To help grape growers in the state, the University of Missouri College of Agriculture, Food and Natural Resources (CAFNR) founded the MU Grape and Wine Institute (GWI). At the GWI, research is conducted on the best winemaking and grape-growing practices. The group also hosts regular events and workshops to help producers stay current on the latest technology and management policies.

A growing concern for researchers at GWI is the possibility of Pierce’s Disease in Missouri. An update on the potential of the disease in Missouri, diagnosis symptoms and ways to properly manage a vineyard for disease prevention will be presented in Columbia on May 6 by nationally known experts at the Missouri Pierce’s Disease Workshop: Evaluating and Mitigating Risk workshop.

“This disease causes a lot of problems in the warmer climates of Texas and in Florida where it makes it almost impossible to grow grapes,” said Misha

Arkansas and Mars variety grapes are grown at the Southwest Research Center. Their sweet taste is similar to Concords, which are often found in juices and jams.

Kwasniewski, CAFNR assistant research professor and enology program leader. “Historically we have not seen it here due to our colder winters, but we did confirm a case last year on a vineyard in the state.”

Pierce’s Disease was first diagnosed in California in 1892 and since has been identified in vineyards in the southeast and Mid-Atlantic states and as far north as Oklahoma. It is caused by a bacterium that survives and multiplies in the living tissue of grapevines.

Once infected, the disease cuts off water and nutrient circulation throughout the vine. Symptoms include leaves become yellow or red along margins, fruit clusters shrivel and wood on new growth matures irregularly with producing patches of green within the mature brown bark.

“If you are a grape grower, it’s important to keep a look out for this,” said Kwasniewski. “We are bringing in some of the top experts to help us control this. As the same with many diseases, once it is not contained, it can spread real easy. Management will be key here to prevent whole vineyards from going down.”

Joining MU’s researchers at the workshop will be Featured speakers will be Jim Kamas, assistant professor and extension specialist at Texas A&M University and Jim Wolpert, viticulture extension specialist emeritus from University of California.

Check-in and registration begins at 9:30 a.m. and the program concludes at 3:30 p.m. at the Hampton Inn Conference Center across from the MU campus.

Registration is required and costs $40 per person and includes a buffet lunch. Registration deadline is May 1st. Visit www.brownpapertickets.com/event/626114 for more information and to register.

The MU Grape and Wine Institute’s researchers work on projects involving cultural practices for Missouri soils and climate the development of disease-resistant and high-yield grape verities, insect and pest controls, rootstock development and wine production at the MU campus and at several of CAFNR’s outstate research centers. Teaching vineyards are established at the Horticulture and Agroforestry Research Center in New Franklin and at the Southwest Research Center near Mt. Vernon. For more information about the MU Grape and Wine Institute, visit http://gwi.missouri.edu/.

Misha Kwasniewski, Assistant Research Professor & Enology Program Leader, talks to a group at HARC about the research going on with grapes.Misha Kwasniewski, Assistant Research Professor & Enology Program Leader, talks to a group at HARC about the research going on with grapes.