Grass Affected

Many turfgrasses especially Kentucky bluegrass, Ryegrass, Zoysiagrass and Bermudagrass


Diagnostic Description

  • First appears as light yellow flecks which enlarge and become small, spore-filled, reddish-brown pustules. In a severe infection, turf has a yellowish to brownish, unhealthy appearance, mowing equipment is covered with spores as are clothing and/or shoes of those walking through an infected area.



Conditions Favoring Infestation and Typically Yearly Occurrence

Favored by warm, humid weather, grasses growing slowly due to insufficient nitrogen or compacted soils. Summer for cool-season grasses; Spring and fall for warm-season grasses.