Oak wilt is a disease caused by a fungus in the xylem, the water-carrying cells of trees. As the term implies, it affects oak trees with red oaks being most susceptible. The fungus blocks the flow of water and nutrients from the roots to the crown, causing the leaves to wilt and fall off, usually killing the tree.
The deadly disease is spread both above and below the ground. After red group oaks die from the disease, fungal spore mats form under the bark. In the warmer months, these spore mats emit a sweet odor that attracts sap-feeding beetles and bark beetles. The insects are also attracted to fresh tree wounds. Because of this, they spread the dangerous fungus from infected trees to healthy trees. Transmission also occurs underground through interconnected roots when red group oaks graft to each other.
Oak wilt infection is typically very noticeable in red group oaks, but harder to identify in white oaks. A brown coloration will develop on leaves starting at the outer edge and progressing inward. There will also be branch dieback starting at the top of the tree’s canopy and moving downward. Leaves will suddenly wilt in the spring and summer and may even fall while there is still some green on them.
A successful oak wilt control program must account for all possible forms of transmission. As beetles are most active in the warmer months, it is advised to avoid pruning in spring and summer because those resulting wounds can attract high numbers of these sap-feeding insects who can spread oak wilt.
If an oak tree is wounded during peak beetle season, it should be sealed with Treekote Wound Dressing to prevent or slow the transmission of oak wilt. This will also slow the wound’s natural recovery, but discourages beetles from landing on those areas. Wounds are typically not susceptible to oak wilt after 72 hours.
Treekote Wound Dressing is an asphalt-based emulsion that can withstand hot, cold, wet and dry weather. It should be sprayed on in a thin layer to the affected area. When applied within 3-days of pruning or damage, Treekote Wound Dressing has been effective at warding off beetles. All cuts greater than ½ inch should be treated.
Oak wilt is a serious disease that can spread rapidly and be fatal for the red oak group. It is important to be proactive in prevention measures. Treekote Wound Dressing is essential to sealing wounds that may attract sap-feeding beetles, who may in turn transmit the disease to healthy trees. Eaton Brothers offers their Treekote Wound Dressing for a convenient to use, easy to cleanup solution.
