Fairy Ring

Disease

Many Basidiomycetes


Fairy rings tend to grow in circle shaped patterns through the organic matter in the soil, mat, and thatch, first appearing as dark green circular rings or arcs in the turf. Rings can range from less than one foot to more than 100 feet in diameter, and often appear as areas of increased growth, known as the "zone of stimulation." In periods of heat or drought stress, affected areas may result in dead rings of turfgrass. The area of stimulated growth is thought to be due to organic matter breakdown which releases nitrogen sources, subsequently made available to the turfgrass plant.

Fairy ring fungi live and survive by spores or other means in dead organic matter in the soil or thatch. Most prevalent in sandy soils, these fungi are thought to be former forest dwelling fungi, which have turned into true saprophytes. Fairy rings occur in many different shapes, sizes, and patterns, some may be accompanied by above ground fruiting mushrooms known as basidocarps.

  • Crops Affected: Turfgrass

    Damage

    The location of this disease is home lawns and golf courses. General symptoms are a circle, patch, or irregular coloring. Foliar symptoms are browning and yellowing. This can occur during the months of March, April, May, June, July, August, September, October, and November. Hosts of the disease are Kentucky Bluegrass, Perennial Ryegrass, Tall Fescue, Fine Fescue, Creeping Bentgrass, and Annual Bluegrass, although all turfgrasses are susceptible hosts for fairy ring.

    Management

    Management or removal of fairy rings can be expensive, and often unnecessary. However in situations where fairy rings must be dealt with, such as on golf course putting greens, some options are available. The most often recommended cultural practice is fertilization to stimulate growth and mask the dark green zones of stimulation. However, identification of the fairy ring fungus is important due to the risk of exacerbating the problem with particular fungi. Digging the fairy rings out of the turf stand is an effective way to manage the problem. Removal of the area immediately surrounding and including the fairy ring, including sod and soil to a depth of 1 ft, and replacing with uninfected soil, reseeding or laying sod can effectively alleviate the problem. This practice is obviously time consuming and costly.

    Applications of fungicides and wetting agents have achieved limited and erratic success in the control of fairy ring, however two fungicides, flutolanil and azoxystrobin, have shown some success in disease management. For best results, the rings should be aerified or have holes poked in them, and fungicides should be drenched into the upper rootzone.

    If the problem of fairy rings persists and is of the utmost concern, removal of sod and soil fumigation can be used to eradicate the problem.