Thousand Cankers Disease Discovered in East Tennessee

Thursday, August 05, 2010 | 12:02 pm
A black walnut tree branch infected with Thousand Cankers Disease.
A black walnut tree branch infected with Thousand Cankers Disease.
NASHVILLE – The Tennessee Department of Agriculture today announced the discovery of Thousand Cankers Disease (TCD), the first detection of the destructive tree pest east of the Mississippi River. The discovery was made in July by a TDA forester.    
“The discovery of TCD in Tennessee is unexpected, but we’re prepared to help slow the spread of the infestation and protect our forest resources.” said state Agriculture Commissioner Ken Givens. “We will be working closely with stakeholders to determine the extent of the infestation and to take steps to limit its spread.”
TCD is a progressive disease that kills a tree within two to three years after initial infection. The disease-causing fungus, Geosmithia, is transmitted by a small twig beetle. Branches and trunk tissue are killed by repeated infections by the fungus, as the beetles carry the fungus into new bark.
The TCD discovery comes a week after emerald ash borer (EAB) was found. Both TCD and EAB have the potential to cause significant damage to Tennessee forests. It is imperative that citizens work to prevent the spread of both.
In response to the find, TDA plans to issue a quarantine in Knox county prohibiting the movement of firewood and black walnut nursery stock and limiting the movement of  black walnut timber and other material that can spread TCD. TDA plant inspectors and foresters will conduct a thorough survey of trees in the areas to assess the extent of the infestation and to see if more quarantines are warranted.
The Tennessee Department of Agriculture Division of Forestry estimates that 1.38 million black walnut trees in Tennessee’s urban areas are potentially at risk from TCD. The risk represents an estimated value loss of $1.37 billion. There are an estimated 26 million black walnut trees on Tennessee public and private timberland potentially valued as high as $1.47 billion. 
TDA officials urge area residents and visitors to help prevent the spread of TCD and EAB:
  • Don’t transport firewood, even within Tennessee. Don’t bring firewood along for camping trips. Buy the wood you need from a local source. Don’t bring wood home with you.
  • Don’t buy or move firewood from outside the state. If someone comes to your door selling firewood, ask them about the source, and don’t buy wood from outside the state. 
  •  Watch for signs of infestation in your black walnut trees. If you suspect your black walnut tree could be infested with TCD, visit for an online symptoms checklist and report form or call TDA’s Regulatory Services Division at 1-800-628-2631.

 For more information about other programs and services of the Tennessee Department of Agriculture visit .

A black walnut tree branch infected with Thousand Cankers Disease.97.87 KB
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