Rust on Zoysia is caused by Puccinia spp. During the initial stages of disease development, yellow lesions enlarge. Inside these lesions, the fungus produces numerous spores that break through the epidermis and are blown by wind and splashed by rain to new infection sites. Masses of orange spores (uredinia) within pustules covering the leaf blades. When disease progresses rapidly, severely affected areas may appear thin and weak, and may be red, brown or yellow.

A closer look at leaf blades with uredinia of Puccinia sp. The rust fungus is an obligate parasite and requires living tissue for its existence. Urediniospores of Puccinia graminis. Rust fungi can produce up to five different types of spores; however, only urediniospores are significant in the disease cycles of rusts in turfgrass.