Long Summer Days Equate To Intense Irrigation Management July 17, 2011 By Keith Happ

(L) Skilled maintenance personnel scout the course daily during the ‘Dog Days of Summer,’ looking for hot spots and signs of wilt.   This is classic foot printing;  the turf is under wilt stress and collapses under traffic stress.  Water management is vital for this turf to survive the day.   (R) There is a distinct difference between irrigating the turf and cooling it with syringing techniques.  During the heart of the summer, sound water management is essential to turf survival.  Syringing to cool the turf can take only a minute or two, and depending on the weather, it may have to be repeated several times during the day. 



They are referred to as the dog days of summer and the summer is well underway.   The Mid-Atlantic Region is in the grip of high temperatures, accompanied by fluctuations in humidity.   When this combination of weather factors occurs, irrigation management becomes the number one priority.  Many superintendents and their crews are putting in long hours by cooling the turf and judiciously applying water only where and when it’s necessary. 

This month we have experienced radical and rapid changes in the humidity levels, and these changes are stressful on fine golf course turf.  While low humidity is a comfortable condition for golfers, it is much more stressful on turfgrass.  The turf cools itself by releasing water (transpiration) to the atmosphere.   During high temperatures and low humidity this cooling process uses a great deal of stored energy from the regionalUpdateContents.  Conversely, high humidity conditions place stress on both the golfers and the turf.  When the air is saturated with moisture, the turf is not under the same level of stress.  Simply put, the plant is not losing as much water to the atmosphere, and its cooling process is not as efficient.   

There is a fine line between irrigating and cooling the turf; in other words, beneficially cooling the turf or over-watering the grass can be damaging.  During high temperature conditions it is essential not to over-wet the soil for fear of damaging the turf and its regionalUpdateContents.  Water is an excellent conductor of heat.   As a golfer, when you see the maintenance crew checking a putting surface or a hot spot in a fairway, allow them time to complete the inspection so they can maintain the playing quality of the golf course.   A few moments for preventive care means a lot at this time of year. 

There have been concerns about bacterial wilt damage on bentgrass.  Samples have been submitted to laboratories and confirmation has been received.  Unfortunately, labeled controls are not available for this problem.  If you suspect this is a problem at your course, send a sample to a qualified laboratory for definitive diagnosis.  If you have any questions, contact the Mid-Atlantic regional offices.

Mid-summer is the time to examine the mowing equipment and sharpen all cutting components if necessary.  Bedknives should be dressed, and reel blades reels may need to be sharpened.  Many operations have spin-grinding equipment that allows for very efficient and rapid sharpening of all reel mowers.  Using sharp mowers is an important Best Management Practice (BMP), so don’t let dull mowers lead to weak, disease-prone turf.  Poor cut quality can cause shredded leaf tips, which can lead to complaints about playing quality.  Take the time to sharpen and adjust the tools of the trade.  The effort will be well worth the while.

Always remember that the agronomists of the Mid-Atlantic Region are part of your agronomic support team.  If you have a question or concern, especially now, give us a call or send an e-mail.  Stan Zontek, ( or Darin Bevard ( at 610-558-9066 or Keith Happ at ( at 412-341-5922.