Shoot blight and leaf blight caused by sycamore anthracnose. Leaf blight lesions typically extend along the leaf veins. Occasionally, this leaf blight symptom is confused with foliar browning caused by summer leaf scorch, which develops along the leaf margins and between the veins. Ash Anthracnose Ash anthracnose is a common but seldom serious problem on white and green ash in Nebraska. The disease is caused by the fungus Apiognomonia errabunda .
Symptoms first appear as water-soaked spots on the expanding shoots and leaves.
Brownish green lesions and leaf deformation caused by ash anthracnose. The lesions are often associated with leaf veins and margins. Growth of the infected tissue slows or stops as the rest of the leaf continues to expand. As a result, the leaf tissue around the lesion becomes twisted and wrinkled. Defoliation also may occur.