Fairy Ring Biology and Management in Tlirfgrass

By Michael Fidanza, Phillip Colbaugh and Steve Davis

airy ring is the name commonly given Fairy ring biology to circles of mushrooms or rapidly in turfgrass Fgrowing, lush green circular bands observed in established turfgrass areas On the surface, fairy ring symptoms can (Couch, 1995). include rings or arcs of dead or unhealthy The term "fairy ring" originated out of turf, rings of dark green stimulated and myth and superstition from the Middle actively growing turf or circular patterns of Ages. For example, magical fairies were mushrooms. Below the surface, the fungal thought to dance within the circles of mycelium often grows in a roughly circular mushrooms at night. A popular myth in or ring pattern through the soil, breaking Holland stated that the dead grass in the down organic matter and releasing nitrogen ring center marked the place where the in the form of ammonia. devil churned butter. As a result, soil microorganisms process In Scotland, it was bad luck for a the ammonia into nitrates, which is then farmer to till the land where fairy rings readily available to turfgrass roots (Couch, were observed. In 1995; Vargas, 1994). The conspicuous, England, however, it actively growing rings of green turf are the was considered good result of this nitrogen release in the soil. Despite the legends, fairy fortune to build a According to Couch (1995), fairy ring ring disease occurs house on land with disease can be classified into two groups: fairy rings (Couch, edaphic and lectophilic. Edaphic originates worldwide in all cultivated 1995; Shantz and from the Greek edaphos — referring to soil turf grasses, and is frequently Pie-meisel, 1917). or earth as a foothold for higher plants, Despite the leg- while lectophilic is composed from the observed on golf course ends, fairy ring dis- Latin lectus meaning bed, litter, or thatch putting greens; fairways, ease occurs world- and the Greek philos meaning love of, or wide in all cultivated favorably disposed toward. tees and roughs, and also turfgrasses, and is fre- Edaphic fairy rings are produced by general lawn areas. quently observed on fungi that primarily colonize the soil. Lec- golf course putting tophilic fairy rings are produced by fungi greens, fairways, tees that primarily colonize the thatch and leaf and roughs, and also general lawn areas. litter. Fairy ring is attributed to more than 50 Fungi that cause edaphic fairy rings can species of soil inhabiting, basidiomycete- extend mycelium growth to a depth of 2 to type fungi (Couch, 1995; Smiley et al., 3 feet in the soil profile (Couch, 1995; 1992; Smith et al., 1989, Watschke et al., Shantz and Piemeisel, 1917). Lectophilic 1995; Vargas, 1994). In turfgrass ecoysys- fairy rings are more likely to develop on tems, these basidiomycete or "mushroom" putting greens and other closely mowed, fungi primarily colonize the thatch and high maintenance turf (Couch, 1995; organic matter component in soil. In turf- Fidanza et al, 1998; Fidanza, 1999). grass areas, fairy ring symptoms can be Fairy rings, whether edaphic or lec- expressed in many different ways. tophilic, can range in size from a few inch- es to several feet in diameter (Smiley et al., 1992). Also, edaphic and lectophilic fairy (Watschke et al., 1995). Recently, fairy ring rings are classified into three categories has become an increasing problem on golf based on symptom expression (Couch, courses throughout the country. 1995; Fermanian et al., 1997; Shantz and Increased fairy ring symptoms have Piemeisel, 1917; andWatschke et al., 1995). been observed in New England this past fall Although many basidiomycete-type following the hot, dry summer. Fairy rings fungi can cause fairy ring, turfgrass in this region are caused primarily by researchers have identified the most com- Marasmius, but Agaricus and Lycoperdon mon types (Couch, 1995; Fidanza, 1999; spp. are also prevalent. Smiley et al., 1992). In many cases, edaph- The Northeast and mid-Atlantic regions ic fairy rings are attributed to: experienced one of the worst years for fairy * Marasmius, ring problems on greens and fairways. Fairy * Chlorophyllum, ring is more noticeable and therefore more * Lepiota (this fungus produces the serious on greens due to surface quality "really big" mushrooms), and expectations. In these regions, fairy rings * Agaricus spp. (referred to as the are attributed to Marasmius, Chlorophyl- "meadow mushroom"). lum and Lycoperdon spp. Recently, many cases of lectophilic fairy In the South and ring have been attributed to Lycoperdon Southeast, Lycoper- spp. (referred to as the "puff-ball" mush- don spp. has become In recent years, fairy ring room) (Couch, 2000; Fidanza et al, 1998; increasingly prob- \)ecome an increasing Fidanza, 1999). lematic on greens, ^ Fairy ring, either edaphic or lectophilic, while Marasmius, problem OH golf Courses has also been caused by the following: Chlorophyllum and i\irQUAl0Ui j/^ country. * Scleroderma, Agaricus spp. are also ^ J * Tricholoma, observed on golf * Clitocybe, course turf * Agrocybe, Due to an increase in the construction * Bo vista (similar to Lycoperdon), and use of sand-based greens coupled with * Coprinus ("mica cap" mushroom), the trend toward low fertility, low cutting * Panaeolina ("haymaker's" mushroom height, demand for increased green speed — common on home lawns), and intense maintenance to those greens, an * Coprinus ("shaggy mane" or "inky cap" increase in lectophilic fairy ring caused by mushroom), and Lycoperdon spp. has been observed. * Conocybe spp. ("dunce cap" mush- In Florida, lectophilic fairy ring symp- room), toms from Lyco-perdon spp. are common- * and more (Barron and Hsiang, 1999; ly observed on new or rebuilt ber-muda- Fidanza, 1999). grass greens within one year after sprigging. In the upper Midwest, severe "killing rings" (lectophilic —Type C) have been Appearances in 1999 observed on "push-up" greens and newly Turfgrass injury symptoms and damage built, sand-based USGA greens after about due to fairy ring typically occur during peri- one year. Throughout the Midwest, fairy ods of hot, dry and drought-like environ- rings are attributed to Marasmius, Chloro- mental conditions. phyllum and Agaricus spp. For example, in Florida it is common to Edaphic fairy rings in the Northwest observe fairy ring symptoms during the caused by Marasmius spp. are commonly prolonged dry, low rainfall period of late observed on greens, fairways, parks and winter through early spring. In many other lawns from spring to early fall. In the South- parts of the United States, fairy ring symp- west, fairy ring is frequently attributed to toms are observed during the hot, dry sum- Agrocybe and Bovista spp. (similar to mer months and sometimes into the fall. Lycoperdon spp.). During dry periods, mushrooms will often appear within a day after a heavy rain How do fairy rings turf managers can plan ahead to manage the symptoms, control the fairy ring fungus kill turf? and maintain healthy turf. Turf pathologists currently agree that Preventive option. Here is an example the fungal mycelium in the soil can accu- of a preventive approach. This example of mulate in large amounts and also will coat a preventive strategy began at Sun 'N Lake sand and soil particles, which results in a Golf Club in Sebring, FL (Fidanza et al., soil profile that is hydrophobic or "water- 1998). The golf course had rebuilt nine repelling." The result is a soil profile that is putting greens during the spring of 1995, hydrophobic or water repellent. however, severe turf injury symptoms due Therefore, the turfgrass plants are to lectophilic fairy ring were observed dur- injured or killed due to competition for ing the following spring. water and nutrients. Once the soil profile Prior to reconstructing the nine remain- or thatch (which is colonized by the fungal ing greens, the club wanted to prevent fairy mycelium) becomes dry or hydrophobic, it ring from again becoming a serious prob- is difficult to re-wet. lem. Club officials consulted with Dr. Mon- In summary, previous research reveals ica Elliott of the University of Florida to that fairy ring fungi can injure or kill turf- develop a preventive solution. grass from a complex combination of the The nine additional greens were rebuilt development of hydrophobic soil condi- during the spring of 1996 in the same man- tions, release of compounds toxic to turf- ner as before, namely by using a sand-based, grass roots and the depletion of available modified USGA specification plan. The nitrogen for plant growth (Couch, 1995; nine, newly rebuilt greens were sprigged in Watschke et al., 1995). May 1996 with "Tifdwarf" bermudagrass. In November 1996, the greens were over- seeded with "Gator" perennial ryegrass. Management options For this field study, the nine recon- in turfgrass structed greens were split, with one-half Recent ad-vances in turfgrass research receiving a treatment program of ProStar have made it possible for golf course super- (50WP fungicide plus Primer soil wetting intendents and other turf managers to man- agent — 3 oz. + 6 fl. oz. per 1000 sq. ft.), age fairy ring with and the second half was left as an untreat- preventive as well as ed check for comparison. curative approaches. At the time of this study, ProStar 50WP Recent advances in turfgrass The decision was the only fungicide labeled for fairy ring research have made it pos- regarding a manage- control. Also, a soil wetting agent was ment strategy included to help alleviate the hydrophobic sible for golf course superin- depends on whether soil conditions. tendents and other turf man- the actual fungus is The fungicide/soil wetting agent tank- edaphic (soil inhabit- mix was first applied in September 1996 agers to manage fairy ring ing) or lectophilic and continued at six-week intervals with preventive as well as (thatch inhabiting), through January 1997 for a total of four the level of turf main- preventive applications. curative approaches. tenance (i.e., putting By March 1997, necrotic injury symp- green, fairway or toms attributed to lectophilic fairy ring home lawn) and the (identified as Lycoperdon spp.) began to degree to which the symptoms are appear on the untreated half of each green. expressed. The appearance of fairy ring corresponded Also, by knowing the environmental to the typical dry, drought-like environ- conditions or time of year most favorable mental conditions common in Florida at for the appearance of fairy ring symptoms, that time of the year. An average of 23 rings were observed on and the use of surfactants to thoroughly the untreated half of each green. The wet the soil profile plus fertilization to pro- majority of the rings ranged from <1 to 2 mote healthy turf and therefore mask the feet in diameter. symptoms (Couch, 2000; Watschke et al., The overall quality in the untreated half 1995). Fairy ring symptoms may be tem- of each green was considered unacceptable porarily alleviated but the fairy ring-causing by the superintendent. No necrotic rings or fungus is still viable in fairy ring symptoms, however, were the thatch or soil. observed on the treated half of each green. Destructive meth- Although TLOt OiWOyS Due to the severe turf injury on the ods are another way to pract{cal on golf COUTSe tU i untreated half of each green, a curative control fairy ring application of ProStar 50WP plus Primer (6 (Watschke et al., fairy ring can abo be oz. + 6 fl. oz. per 1000 sq. ft.) was delivered 1995) These methods manage¿ through to the untreated half of each green in may be costly, labor March 1997. intensive, unsuccess- suppression and by By May 1997, no necrotic rings or turf ful anc not alwa s * r y r destructive methods. injury was visible in those previously practical for most golf untreated halves, and the bermudagrass had courses. One example recovered and filled into the previously is to remove the turf in the area affected by damaged areas. fairy ring, till and mix the underlying soil in Curative option. Here are alternative several directions, then reseed or sod the strategies to consider. For lectophilic fairy area. By mixing the soil, this will promote rings on greens, success has been observed the natural antagonism that occurs among with the use of a combination approach of fairy ring mycelium in the soil. Fairy rings a fungicide plus soil wetting agent. Couch have been known to dissipate when they (1999, 2000) has outlined an integrated contact each other due to their antagonistic approach of fungicide, soil wetting agent, nature. irrigation and cultural practices to manage Curative research efforts are underway. fairy ring in turf. Research on fairy ring management in- The wetting agent helps to alleviate the cludes the evaluation of fungicides, various hydrophobic soil condition, thereby allow- soil wetting products and types and cultur- ing water to move more easily through the al practices (Colbaugh, 1999; Couch, 1999; thatch and soil profile, and the irrigation Fidanza, 1999). The goal is to develop helps the fungicide penetrate and reach the strategies aimed at maintaining healthy turf, fungus. reducing hydrophobic soil conditions In some Southern California cases, attributed to the fairy ring fungi and con- heavy irrigation following a fungicide appli- trolling the fungus. cation seemed to "push" the material At Texas A& M University, research is through the sand profile away from the lec- also focused on understanding the biology tophilic fungal mycelium in the thatch and pathogenic nature of these fungi that (Fidanza, 1999). cause fairy ring in turf. Preliminary results Research at Texas A & M has shown the show that some types of fairy ring fungi can positive benefits of subsurface injection inhibit creeping bentgrass growth and equipment to control fairy ring (Colbaugh, development, while other types have no 1999). This provides better placement of a influence. control agent into the thatch and soil pro- You can help with this research! Please file, thus reaching the fairy ring fungus with forward samples of actual mushrooms, or no adverse effects to the desired turf photos of fairy ring mushrooms and turf Although not always practical on golf symptoms, to the following: course turf, fairy ring can also be managed Fairy Ring Characterization Project through suppression and by destructive Attention: Dr. Phillip Colbaugh methods. Symptoms can be suppressed Texas A & M University through the use of cultural practices such as 17360 CoitRoad aerification, core cultivation, deep watering Dallas, TX 75252 If you are sending a mushroom, wrap Press, Minneapolis, MN. the sample in a dry paper towel and ship Smith, J.D., N. Jackson, and A.R. Woolhouse. 1989. overnight. Along with the actual mush- Fungal diseases of amenity turf grasses. E. & F. room sample or photo, be sure to include Spon., London. relevant information such as state, location on golf course, turfgrass variety and envi- Vargas, J.M. 1994. Management of turfgrass dis- ronmental conditions. eases. CRS Press, Boca Raton, FL.

Watschke, T.L., PH. Dernoeden, and D.J. Shetlar. — Michael Fidanza is in Research 1995. Management of turfgrass pests. CRS Press, and Development at Aventis Boca Raton, FL. Environmental Science; Phillip Colbaugh is associate professor of Urban Plant Pathology at Texas A &£ M University; ana Steve Davis is technical representative for Aventis Environmental Science.

References

Barron, G. and! Hsiang. 1999. Fungi on fairways. Golf Course Management. December issue, pages 58-61.

Colbaugh, P. 1999. Turfgrass pathology research summary - 1999. Texas A & M University. Dallas, TX.

Couch, H.B. 1995. Diseases of turfgrasses. Kreiger Publishing, Malabar, FL.

Couch, H.B. 1999. Results of turfgrass disease control trials— 1999. Virginia Polytechnic Institute and State University. Blacksburg, VA.

Couch, H.B. 2000. The turfgrass disease hand- book. Kreiger Publishing, Malabar, FL.

Fermanian, T.W., M.C. Shurtleff, R. Randell, H.T. Wilkinson, and PL. Nixon. 1997. Controlling turf- grass pests. Prentice Hall, Upper Saddle River, NJ.

Fidanza, M.A.. 1999. Conquering fairy ring disease with new tools. Golf Course Management. March issue, pages 68-71.

Fidanza, M., M. Elliott, R.Hickman, M. Hopkins, and D. Spak. 1998. A preventive approach to fairy ring disease management on putting greens. Agronomy Abstracts: 145.

Shantz, H.L. and R.L. Piemeisel. 1917. Fungus fairy rings in Eastern Colorado and their effects on vegetation. J. Agrie. Res. 11:191-245.

Smiley, R.W., P.H. Dernoeden, and B.B. Clarke. 1992. Compendium of turfgrass diseases. APS