Thousand Cankers Disease

Trees, especially those with which we deal on a regular basis, are often seen as strong and impenetrable monuments. And as prevalent as that perception is, we often forget that species like Black Walnut and White Oak are susceptible to illness, just like any other living thing. Insects, floods, and fires have tremendous impacts on the health and ever-changing appearance of our forests. Additionally, diseases, some of which we know well, affect our trees and forests, at large, in ways that many of us see on a regular basis.

Black Walnut Vulnerabilities

Black Walnuts are valuable trees that stand as primary figures in Illinois forests. They grow anywhere from 40 to 150 ft. tall, and reach diameters ranging from 2 to 4 ft. They’re often spotted by their unique leaf structure and their black bark. As a popular hardwood, they also tend to shrink and swell less than other woods, making them much more desirable for their use in consumer products. They aren’t without their vulnerabilities, though.

What is TCD?

A handful of Walnut species, but specifically black and butternut, are known to be susceptible to a deadly disease called Thousand Cankers (TCD). While no cases of TCD have been documented in Illinois, awareness of the disease and its symptoms is important in order to keep it from spreading to Illinois via transported firewood and untreated timber.

Thousand Cankers Disease is carried by the Walnut Twig Beetle, which travels into the bark of a tree and attacks its vascular system. Once burrowed inside the limbs and trunk of the tree, a grub (immature beetle) develops. While grubs develop, a deadly fungus that clings to the beetles settles into the holes and crevices made by the beetles entering the tree. The fungus then multiplies, wreaking havoc on the tissue of the tree, which results in a visible canker on the bark. In most cases, these trees eventually die from a combination of bark damage and the effects of overall damage on continued production and growth of the tree.

TCD Symptoms

A handful of symptoms are associated with TCD. Typically, walnut tree branches and leaves fan out at their tops. When infected, this top (or crown) begins to thin. Additionally, leaves begin to turn yellow and wilt. When the infection has spread to a critical amount of the tree for an extended period, cankers become apparent on the bark of the tree. If disease appears probable based on such observable symptoms, testing should be conducted to decide. An ideal sample would be a limb showing signs of yellowing and wilting.

Recognizing the signs of disease can help prevent its spread. While disease will still occur, through proper promotion of overall tree health, control is possible.

To learn more or to start the discussion about selling your timber, contact us today.