Curvularia Leaf Spot
Curvularia spp.
Disease of Foliage and/or Roots
Susceptible Turf
Wintergrass, Kentucky Bluegrass, Bentgrass, Fescue, Couch.
Symptoms
- Individual leaves initially show yellow and green dapple patterns that extend downwards from the leaf tip.
- Infected leaves turn brown, then grey as they shrivel and die.
- Irregular shaped patches of thinned turf appear, often coalescing to affect larger areas.
- Stolons and leaf sheaths may also rot.
Conditions Favouring Disease
- Curvularia Leaf Spot occurs in areas that experience prolonged leaf wetness for several consecutive days.
- Curvularia spp. occurs at temperatures, 25°C to 35°C.
- Soil compaction and excessive levels of nitrogen and thatch.
Management Tips
- Maintain balanced fertility.
- Increase the height of cut.
- Avoid nitrogen applications in the spring when the disease is active.
- Increase the air circulation.
- Avoid over watering.
- Improve the drainage of the turf.
- Reduce thatch accumulation.
General Comments
Curvularia is mostly a secondary disease after primary pathogens such as Spring Dead Spot and Helminthosporium, have infected turfgrass.
Physiological changes in the turfgrass plant can increase susceptibility to Curvalaria when the light intensity is low or when the mowing height is lower than recommended for the specific situation.
Sometimes called "Melting Out".