Lawn Fungus in Georgia

Identification

• Dollar spot and "take-all root rot" are among common lawn fungi in Georgia, according to the University of Georgia Extension. Dollar spot is caused by the fungus Sclerotinia homoeocarpa and affects all cool- and warm-season grasses in Georgia. Take-all root rot is caused by the plant pathogen Gaeumannomyces graminis var. graminis. Frequently affected grasses in the state include bermuda grass, St. Augustine grass and centipede grass. Fescues and bluegrass are rarely infected.

Symptoms

• Take-all root rot is characterized by the appearance of wilted, brown- to bronze-colored round patches on grasses. It ranges up to several feet in diameter. The fungus is prevalent in lawns growing in high pH soils. Dollar spot leads to small, several-inch diameter, sunken brown areas on lawns. With disease progression, the patches turn straw colored and enlarges and merges to create patches.

Management

• Lowering the soil pH and addition of phosphorus and potash to lawns helps to reduced symptoms of take-all root rot. De-thatch lawns regularly and improve drainage. Management of dollar spot includes regular application of adequate nitrogen in the spring and summer. Improve air circulation and mow grass regularly.