Thousand Cankers Disease Found in East Tennessee

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 timberland 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.