Fact Sheets no. The most serious disease of sycamore trees is anthracnose. Anthracnose often is confused with frost damage. The first symptoms appear on young leaves as they unfold.
Older leaves turn brown, and dead areas occur along the leaf veins.
Brown areas eventually enlarge to include the whole leaf. The ends of twigs may be killed back 8 to 10 inches. Cankers may develop on the tree trunk and main branches. Sycamore anthracnose fungus attacks sycamore trees early in the spring, causing a rapid wilt of newly emerging leaves. This rapid wilting is frequently misidentified as frost damage.