Oak wilt, one of the most devastating tree diseases in the United States, is rapidly killing oak trees across central Texas. This infectious disease is caused by the fungus Bretziella fagacearum, which attacks and disrupts the xylem, the water-conducting system in oaks. While all oak species are susceptible, some are more severely affected than others. Effective management of oak wilt requires accurate diagnosis and a thorough understanding of how the pathogen interacts with different oak species.

Proper diagnosis of oak wilt is crucial, as treatment plans can be costly and may impact your property and neighbors. Since oak wilt affects the tree’s vascular system, it often presents with necrotic foliar symptoms. The most common diagnostic methods include identifying leaf symptoms and mortality patterns associated with root graft transmission. In early stages or cases without distinct vein discoloration, samples can be sent to the Texas Plant Disease Diagnostic Laboratory at Texas A&M for confirmation.