Hosts Common on bluegrass and fescue.
Cause Fungi, Curvularia spp., about nine species in all. They live on diseased grass and organic debris at the soil surface. The disease is most destructive in warm weather, from May to October and on compacted soil. These fungi are weakly virulent, commonly isolated from turf with problems and may be components of disease complexes.
Symptoms Root and crown rot resulting in yellowed or dappled green patches. Later, irregular reddish-brown dead patches 2 to 3 inches in diameter appear. Sometimes these spots merge to form dead areas 1 ft or more wide.
Cultural control
- Water in morning. Light, frequent watering tends to prolong the disease. Use enough water, based on local growing conditions.
- Pick up clippings.
- Do not let grass get matted.
- Maintain vigorous turf.
- Avoid thatch.
Chemical control
- Daconil Weather Stik at 2 to 5.5 fl oz/1,000 sq ft depending on whether the application is preventive or curative. Group M5 fungicide. 12-hr reentry.
- Encartis at 3 to 4 fl oz/1,000 sq ft. Do not use with oil-based pesticides. Group 7 + M5 fungicide. Reentry when sprays have dried.
- Interface at 5 to 7 fl oz/1,000 sq ft on bermudagrass only. Maintain agitation while spraying. Do not mix with adjuvants. Group 2 + 11 fungicide. 24-hr reentry.
Reference Smiley, R.W., Dernoeden, P.H., and Clarke, B.B. 2005. Compendium of Turfgrass Diseases. 3rd edition. St. Paul, MN: APS Press.