Several species of rust fungi cause diseases of turfgrasses in Maryland. Given the right conditions, rust diseases may infect most of the turfgrasses grown in Maryland.
The first symptoms appear as yellow to orange spots on leaves and stems. These spots enlarge and cause elongated lesions that produce powdery orange to red to brownish spores. These spores rub off easily on hands, shoes, and clothing.
Severely infected areas will have a yellowish or orange appearance and become thin and weak. Rust diseases can occur all season and are favored by temperatures between 70-75 F with high humidity, heavy dew, or rain.
If possible, select rust-resistant cultivars when establishing turf. Maintain proper levels of nitrogen fertilization and avoid evening irrigation.
(PDF) Rust Disease | Purdue Extension Turfgrass Disease Profiles