Friday, July 22, 2011

Virginia Quarantines Movement of Walnut Trees, Products from Richmond Area

The Virginia Department of Agriculture and Consumer Services (VDACS) today placed a temporary quarantine on Chesterfield and Henrico Counties and the city of Richmond following the detection of Thousand Cankers Disease (TCD) in Chesterfield and Henrico Counties.  The city of Richmond is included because of its proximity to the locations where the disease was detected.

Matthew J. Lohr, VDACS Commissioner, has established the temporary quarantine in an effort to prevent the artificial spread of TCD. Regulated articles that cannot be moved out of the quarantine area include all walnut plants and plant parts of walnut, including logs, stumps, firewood, roots, branches, mulch and chips.

TCD is a disease complex that attacks walnut trees, Juglans spp. The fungus Geosmithia morbida is vectored by the walnut twig beetle, Pityophthorus juglandis, causing small cankers under the bark of the tree. The beetle introduces the fungus while it tunnels beneath the bark. As more beetles attack the tree, the number of cankers increases until they coalesce to girdle twigs and branches, restricting movement of nutrients and eventually killing the tree. Neither the beetle nor the fungus is native to the eastern U.S.  Thinning or dead branches will initially occur at the top of the tree which will die from the top down. Trees may be infested for many years before showing symptoms. There is currently no preventive or curative treatment for the disease.

TCD has been present in the western U.S. for years; this is the first detection in Virginia and the first time it has been found east of Knoxville, TN, where it was detected in August 2010. Once established, TCD has the potential to spread to uninfested areas, either through natural means or through the artificial movement of infested articles. VDACS employees in the Office of Plant Industry Services are surveying the affected areas in an effort to determine the extent of this infestation and the source of TCD in Chesterfield and Henrico Counties. The actual source may be difficult to determine since the infestation likely occurred several years ago.

Click here for more information on Thousand Cankers Diseases in the Eastern United States.

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