Rust is appearing on perennial ryegrass sports fields that are irrigated or lightly watered.  Rust is favored by relatively warm autumn days with cool nights that produce heavy dew. With nearly 5,000 different species of rust, the likelihood of variation in rust pathogens on turf would be expected. On Kentucky bluegrass, stem rust is the most widespread. Crown rust is the most widespread on tall fescue and perennial ryegrass. Symptoms initially appear as light green specks on the leaf blade that within a week turn orangish-reddish color. The appearance of pustules (uredinal), which contain the spores that can be spread and continue to cause infection. Rust is most favorable on drought stressed slow growing turf. If rust is a problem, fall fertilization can slow disease progress along with watering.  Signs of rust include shoes turning orange, tires on carts having a orangish tint, and mowers appearing orange from the spores.