Bacterial Leaf Scorch | Atlanta, Georgia
Bacterial Leaf Scorch | Signs and Symptoms
Bacterial leaf scorch is a chronic, eventually fatal disease that is most noticeable in the early fall. Symptoms include premature leaf browning, marginal necrosis and defoliation. Infected trees leaf-out normally the following year; however leaves on a few more branches turn prematurely brown in late summer. These events repeat themselves over a period of several years until the entire tree turns prematurely brown. Trees gradually decline over the years as twigs, branches, and limbs die from continual defoliatior. Because symptoms of this disease can sometimes be confused with other abiotic, stress-related problems, it is advisable to have the diagnosis confirmed with a special laboratory test.
Symptoms of bacterial leaf scorch are described as marginal leaf burn and are very similar to drought stress symptoms. In addition to marginal leaf burn, there is a defined reddish or yellow border separating the necrosis from green tissue
• Watering trees. Atlanta summer weather can sometimes be hot and accentuated by periods of drought lasting anywhere from a week to several months. A study conducted by the University of Maryland demonstrated a possible correlation between bacterial leaf scorch and water stress. Based on their results, Atlanta tree owners and landscape managers may be able to prolong the lives of their scorch-infected trees by applying supplemental water during the hot, dry parts of the growing season.
• Tree–injections. There are commercial tree-injection products containing the antibiotic oxytetracyclene which are sold and used for the management of bacterial leaf scorch disease. Injections, which are made into the root flare at the base of the tree, may provide temporary remission of the symptoms. To be effective, however, the antibiotic would need to be re-injected, perhaps annually or more often. In Atlanta, we have observed symptoms in pin oaks and red oaks treated with antibiotic injections can be delayed by several weeks. These treatments do not cure infected trees, but they may prolong the life of the tree. For more information please see University of Kentucky Cooperative Extension ServiceArborist Evaluations