In the previous Florida regional update by Todd Lowe, it was noted that environmental conditions are now conducive to the resumption of sustained bermudagrass growth. Along with increasing daytime and nighttime temperatures, day length also is increasing. Unfortunately, but typical for spring in Florida, April showers have been rare; and instead of bringing May flowers, course managers have been far more concerned about dealing with drought stress and outbreaks of fairy rings.

Fairy rings

In South Florida, the winter play season has essentially come to an end, and at facilities throughout the area summertime cultural management practices of core aeration and aggressive verticutting are being initiated. While these practices are unpopular because they are disruptive and an inconvenience, it is important that they be undertaken as soon as possible for winter recovery and to reestablish optimum turf health.

Rainfall was well below average through the winter and spring, and low humidity and windy conditions have made it difficult to prevent drought stress and maintain the green aesthetics through all areas. It’s important to remember, there is no such thing as a perfect irrigation system, and irrigation is, at best, a supplement to rainfall. Naturally, any and all system deficiencies are highlighted at this time. Fortunately, both bermudagrass and Seashore paspalum have very good drought tolerance and will recover as we move into the rainy season and afternoon thunderstorms become a routine. It has also been my experience that the injecting wetting agents into the irrigation system is beneficial and a means of efficiently accomplishing large acreage treatments.

In addition to drought stress and localized dry spots, an increased incidence of fairy rings has been encountered on TAS visits over the past few weeks. Fairy rings occur as a result of organic debris degradation by naturally occurring soil fungi, and while not a true disease, turf health, quality and aesthetic character can be adversely affected. There has been the perception that fairy rings have been a much more pronounced problem with new or recently renovated ultradwarf bermudagrass putting surfaces. However, during 2005 it was found that fairy rings were a major problem regardless of base turf, putting green age, or type of construction. While strictly a personal opinion, the increased incidence of fairy rings that have occurred is at least partially a consequence of the multiple hurricanes that have hit the state over the past couple of years.

As far as keeping this problem suppressed, the best and most consistent results have been achieved with preventative fungicide plus wetting agent treatments. At the very least, these treatments should be initiated as soon as symptoms of an outbreak are observed. Since this is a soil problem, spiking or aeration of the affected areas to open up the turf canopy, followed by irrigation to ensure that the upper root zone is moist, then conducting the fungicide plus wetting agent treatment, and following this with another irrigation application is recommended to ensure that the materials are moved into the upper root zone. Several university plant pathologists recommend that this treatment process be repeated in 30 days. Once fairy rings have become fully expressed, producing a recovery response tends to be quite slow. While fungicide treatments are often used, current research indicates that this provides only marginal benefits. Supplemental aeration, wetting agent treatments, spot fertilization, and hand watering affected areas continue to be recommended for alleviating fairy rings and reestablishing a uniform and healthy turf cover.

As a reminder, you receive a $300 discount on Turf Advisory Service (TAS) visits by pre-paying before May 15, 2006. If you have questions on pre-paying TAS visits, please call our office at 772-546-2620.

Source: John Foy, jfoy@usga.org