Lose A Battle To Win The War

In this case, the ‘battle’ is playability, i.e. putting green smoothness and speed, and the ‘war’ is turfgrass survival.  With this summer’s weather challenges, some courses have already lost major portions of rough and fairways to natural physiological decline or flooding.  Reports of greens being lost are on the rise, and these facilities are now faced with re-grassing this fall.  For others, the fight continues.   

Root depth on many greens is generally two inches or less, and heat indexes in recent weeks have exceeded 115°F, with average daily relative humidities just shy of 100%.  Soil temperatures are frequently in the mid-90s and above.  (Note:  Bentgrass regionalUpdateContent dieback begins when soil temperatures reach about 86°F.)  Most of the weaker species that possess lower thresholds to environmental extremes, such as Poa annua, have long disappeared from greens and surrounds.  Arguably the most difficult to manage area of the golf course, even during favorable conditions, putting green collars have been decimated regardless of species.  For many, the only objective now is to preserve what bentgrass remains on the greens and what Kentucky bluegrass, perennial ryegrass and tall fescue continues to hang on in the surrounds. 

Given the harshness of weather extremes across several geographic regions this summer, additional resources have been generated and can be found below: 

• Many recent USGA Regional Updates discuss summer struggles and outline excellent recommendations for survival.  (http://www.usga.org/Content.aspx?id=26223)
• USGA Senior Agronomist Chris Hartwiger developed a webcast, “Bad to Worse for Creeping Bentgrass - Seven Steps to Help Your Greens Make it Through the Summer”  that includes seven survival recommendations: 1) proper and continuous use of fans (i.e. 24 hours/day), 2) venting the greens when possible via non-disruptive aeration techniques, 3) raising the mowing height and using solid front rollers, 4) mowing less frequently and rolling instead, 5) increasing the use of fungicides, 6) taking irrigation management to the highest level possible, and 7) reducing traffic on the greens. (http://webcast.usga.org/usga/Bentgrass_greens_survival_Hartwiger.wmv )
• Virtually every disease known, and even a few new ones, have been prevalent on cool-season turfgrasses under duress this summer.   For instance, there have been a few titles on turf diseases over the last two weeks, and a daily blog by five contributing university turfgrass pathologists nationwide states,  “Dead Bentgrass Makes Headlines”, “Heat + Rain = Dead Grass”, “No Wind = Dead Grass”, “Heat Wreaking Havoc on Courses Nationwide”, “Relentless Heat and Humidity” and “Stress, Stress, Stress.”  (http://turfdiseases.blogspot.com/) 

Bentgrass Disease Alert

An outbreak of bacterial wilt disease has been identified in many areas in the Northeast, North Central, and Mid-Continent Regions.  Although there are many questions to be answered about identifying this disease, pathologists are recommending that superintendents treat it as bacterial wilt until positive identification methods are developed.  The primary treatments currently known for bacterial wilt are Zero-Tol®, Junction, or Kocide.

In the Dallas/Fort Worth area, there have been three identified bacterial wilt infections in the past few weeks.  Plant health varies with placement of fans.  Disease progresses more significantly on areas where the air flow from the fans is diminished.    

This has been a trying summer for all.  Cool-season turfgrass are in a fragile state, and superintendents and their staffs are feeling the effects of long hours and touch-and-go circumstances.  Now is the time to rely on the wisdom of your superintendent and support the recommendations of professionals.  Slower greens are still quite playable and enjoyable, and, if nothing else, it’s an opportunity to enjoy hole locations in areas of the greens that otherwise are not available when greens are fast.  Respect course closure and cart restriction policies.   

Know what is at stake, and adjust your playability expectations in order to fight another day.  Your fall golf season may just depend on it.