Is It Really Localized Dry Spot?
At the time of writing this update much of the Mid-Atlantic Region has been very dry for several weeks. Some areas have been fortunate to receive rainfall, but by and large, it has been dry. Water resources are often listed as one of the greatest concerns for the golf course industry. As of July 1 st , several golf courses are already being forced to make difficult decisions regarding their on course watering practices because pond levels are approaching critical levels. Without rainfall soon, it will be a long summer for many golf courses.
One problem that rears its head during dry times is Localized Dry Spot (LDS). LDS is a condition that occurs when isolated pockets of soil become water repellant. In many cases, a patch of wilting turf from as small as a dinner plate to much larger dimensions will be located immediately adjacent to healthy turf. Upon probing the soil in these areas, the soil in the wilted area will be powder dry and the soil supporting the healthy turf will be at normal moisture levels. These LDS areas are very difficult to rewet even with repeated hand-watering. Wetting agents can help, but the question that needs to be asked is whether or not the problem is really LDS or something else is at work.
In recent travels, the most severe LDS problems have been closely related to poor irrigation coverage. For example, insufficient overlap of sprinkler heads, irrigation heads interfered with by a new installation (e.g. a new flower bed), heads not coming on, heads not turning, sprinkler heads skewered at strange angles, etc. The bottom line is that water repellency issues may develop over time from repeated wetting and drying cycles, but the underlying cause of these problems in many instances is poor irrigation coverage. Be sure that you evaluate coverage from your irrigation system in these areas of LDS. You may be surprised what you find.
As far as the hot, dry weather goes, precautions should be taken to protect the turf. Limit cart traffic and reduce mowing frequency throughout the golf course. On greens, it may be possible to skip mowing one or two days per week and just roll greens to maintain speeds and ball roll. The goal is to protect the turf. Make sure that your irrigation system is functioning properly. Invest in the extra man hours with hand watering. Here's the bottom line, the current weather pattern quickly identifies deficiencies in the quality of irrigation systems.
This weather isn't abnormal as summer is fully upon us. Now is the time to use some caution when considering maintenance practices, pesticide applications and traffic management. When turfgrass is under drought stress, maintenance practices that would not normally create any problems can be devastating. Be conservative under harsh environmental conditions to keep the grass as healthy as possible. Remember, it is only the first part of July, there is lots of summer weather still ahead for our golf courses.
As always, if the Mid-Atlantic Regional agronomists can be of assistance, contact Stan Zontek ( firstname.lastname@example.org ) or Darin Bevard ( email@example.com ) at 610/ 558-9066 or Keith Happ ( firstname.lastname@example.org ) at 412/ 341-5922.