In the spring time have you ever noticed your sycamore trees looking wilted, just as the new growth starts to emerge? In wet years sycamore trees are very suseptable to anthracnoes disease or leaf blight. It is a fungal pathogen that is greatly infuenced by weather conditions.
In Southern California, years that have late spring rains the damage from this pathogen is more severe. Trees are sererly damaged in these years, but the Sycamore trees usually recover once the weather dries out. The symtoms of anthracnose can look similar to frost damage, but in California frost damage on these trees is extremly rare due to our climate.
The leaves on severly infected shoots turn brown, shrivel and drop they emerge in spring. Less severely infected leaves develop dead patches along the leaf veins but continue to hang on to the tree. Twig and bud infections are dormant during the hot and dry months but reactivate in late fall and continue their destructive phase throughout winter and spring. Sycamore leaf blight may cause complete defoliation of a tree and die back of small twigs and branc