Sycamore anthracnose, Gnomonia veneta, (Sacc. & Speg.) Klebahn (4), prevalent in Iowa (1), belongs to a group of plant diseases with life cycle patterns which suggest the use of fungicidal sprays for their control. In early spring this disease appears as a blight on the young leaves soon after they emerge from the bud (Fig. 1). The blighted leaves become brown to black and frequently appear as if they had been injured by frost. Mature leaf infection characteristically produces elongate brown streaks along the midveins and laterals (Fig. 2), and many such infected leaves fall within two or three weeks. In addition to defoliation, sycamores undergo extensive twig blight. The death of terminal buds stimulates the development of numerous lateral branches which later may also be destroyed. This results in dead clusters of branches, "witches' broom", around a swollen terminal area (Fig. 3).
Proceedings of the Iowa Academy of Science
©1951 Iowa Academy of Science, Inc.
Schuldt, Paul H.
"Sprays for Control of Sycamore Anthracnose,"
Proceedings of the Iowa Academy of Science, 58(1), 209-214.
Available at: https://scholarworks.uni.edu/pias/vol58/iss1/21