Symptoms and Signs

All turfgrass species are susceptible to rust diseases. Environmental stresses contribute to the severity of the disease. When plants become infected by the rust fungi, they are also more likely to be attacked by other pathogens. Initial symptoms include yellow lesions that enlarge over time. Numerous lesions may make leaves appear yellow (Fig. 1). Later pustules develop from the lesions, and when mature, spores break through the epidermis of these pustules and are blown by wind and splashed by rain to new infection sites. Most spores are characteristically orange in color (Fig. 2), but some may be various shades of yellow, red, or brown. When the disease becomes severe, the turfgrass stands may appear very thin and discolored. Death of the turf is possible during severe infections