Anthracnose & Turf

Anthracnose is among the common fungal diseases of turf. According to the North Dakota University Extension, fungi are the most frequent cause of turf disorders. Fungi are microscopic organisms that spread by air or water.

Cause

The Colletotrichum graminicola fungus causes anthracnose on turf grasses. The fungus lives and thrives in rotting organic matter in grass. Fungal growth is favored by prolonged warm temperatures of 80 to 90 degrees Fahrenheit. Grass that is growing poorly or is culturally stressed is more prone to infection.

Damage

Early symptoms of disease include the appearance of irregularly shaped patches of brown grass on lawns. Damaged areas are between 2 inches to 1 foot in diameter. Grass blades show tan or brown spots with black fruiting bodies on dead grass. Mature grass is affected first. New grass stays green longer.

Control

Grow grass in well-drained soil and keep turf in good health. Use disease-resistant varieties and obtain grass from reliable sources. Avoid fertilizing grass during drought or high heat. Dethatch and aerate lawn regularly. Recommended fungicides include polyoxin D and strobilurin.

References

• North Dakota State University Extension: Lawn Diseases
• Purdue University Extension: Anthracnose
• University of Illinois Extension: Anthracnose of Turfgrasses
• University of California Extension: Anthracnose