The state Department of Environmental Conservation announced last week that oak wilt — a disease that kills oak trees — has been detected in South Bristol, which borders Yates County west of Canandaigua Lake.
A concerned landowner contacted the DEC after several oak trees on the landowner’s property in South Bristol began showing signs of oak wilt, including dropping discolored leaves in July and then dying rapidly, according to the DEC. Samples from one of the trees were sent to the Cornell Plant Disease Diagnostic Clinic, where they tested positive for the fungus that causes the disease.
Oak wilt, caused by the fungus Bretziella fagacearum, is a serious tree disease in the eastern United States, killing thousands of oaks each year in forests, woodlots and home landscapes. As the tree attempts to defend itself, it produces gummy plugs to restrict the movement of the fungus. These plugs, together with the growing fungus, prevent the water transport in the tree. As water movement within the tree is slowed, the leaves wilt and drop off, and eventually the tree dies.
Oak Wilt is not new in the Southern End of Canandaigua. It was identified last year by Natural Resource Educator Emily Staychock of the Yates County Cooperative Extension.
This is the second location in Ontario County where oak wilt has been confirmed. The disease was confirmed in the town of Canandaigua in 2016. Ontario County is one of four counties in the state that have confirmed oak wilt infections, according to the DEC. Other counties with confirmed cases of oak wilt are Kings, Suffolk, and Schenectady.
The current treatment method to contain and kill the oak wilt fungus is to remove the infected trees, as well as any nearby oaks that could become infected.The DEC will issue an order establishing a quarantine district prohibiting the movement of oak material out of the immediate area to prevent the fungus from spreading. In addition, the DEC will conduct aerial and ground surveys over the next few weeks to identify additional trees that may be infected.