Many areas of the country are on a record-setting pace for summer weather conditions, and, for many, golf course conditioning is well below golfers’ expectations. Let’s consider what’s affecting these conditions.
First and foremost, remember that cool-season grasses (e.g.Poa annua, bentgrass, perennial ryegrass, bluegrass and fescues) are so labeled for good reason – they don’t perform well in heat! Warm-season grasses (like bermudagrass and zoysiagrass), on the other hand, thrive in the heat. Clearly, the concern has been, and continues to be, the weak performance of cool-season grasses. High soil temperatures make it difficult for plants to survive, even when few other stresses are added. In the case of this summer, the combination of high temperatures and wet conditions from frequent rainfall has caused physiological decline and death of turf on golf courses throughout the region and country.
Although rainfall and heat alone continues to cause problems, poor irrigation systems and/or a compromised regionalUpdateContent zone profile (too much organic matter and finer particle accumulation) intensifies turf loss. Ideally, positive water movement through the soil means oxygen moves-in behind, but poor water movement means insufficient oxygen in the regionalUpdateContent zone, compromising plant growth and transpiration, and opening the door to wet wilt. Wet wilt is the quickest way to lose grass, short of spilling gasoline.
The majority of samples submitted to diagnostic laboratories show no causal pathogen, which points to physiological and/or mechanical causes. Nevertheless, there are a number of diseases adding to turf decline, and the most concerning is bacterial wilt, which has been confirmed on some of the newer bentgrass varieties ( http://apsjournals.apsnet.org/doi/abs/10.1094/PDIS-94-7-0922B). Gray leaf spot ( http://www.agry.purdue.edu/turf/tips/2010/07262010GLS.html), brown patch,Pythium, dollar spot and anthracnose also are part of the mix.
Player and equipment traffic also is adding to the decline. Now is not the time to push the envelope or get creative. When in doubt, don’t do anything fancy.
- Manage water carefully. Hand watering and syringing are preferred over using sprinklers, especially on putting surfaces.
- If the cut is too low, raise it and possibly mow less frequently.
- If moisture is holding in the upper profile, open and vent with small diameter solid tines on a good-quality machine.
- Stay consistent with light and frequent foliar feeding.
- Maintain a solid fungicide program. If the fungicide budget is being depleted, pull back in other areas.
Give us a call to schedule an on-site visit to itemize specific limitations and to
prioritize a plan for moving forward. In the final analysis, turf health comes before playability.
We are always available to assist.
Source: Bob Brame, bobbrame@usga.org or 859-356-3272