This has been and continues to be the most difficult year in over 20 years for golf courses in Kansas City and across the country. Golf course conditioning is well below the golfers’ expectations. Golfers expect exceptional conditions and when those conditions are not meet, the naive golfers place blame on the golf course superintendent immediately.
2010 has been the “perfect storm”
It all began with the cold wet spring and is now been followed bya combination of extreme heat and humidityresulting in a struggle for survivalof cool season grasses like bentgrass, bluegrass, fescues and Poa annua. Let us not forget many courses have had to cut budgets due to the economy, which means superintendents have smaller staffs and smaller budgets for water and critical chemicals.
How has the weather really caused the problem?
The cold wet spring did not allow the grass to develop healthy deep roots, which are necessary to survive the summer heat. The above average rainfall through mid July made the soil saturated. Wet soil maintains a higher temperature than dry soil and it creates a barrier that prevents needed oxygen getting to the roots. Soil temperatures are critical, as cool season grasses will decline when the soil temperature is above 86-degress. Extreme heat and humidity have persisted for over four weeks (soil temperatures are over 100-degrees.) The cool season grasses have been surviving for the last six weeks off reserves in the root systems. Those reserves and the root systems have all but run out. In addition, high humidity has created constant high fungal disease pressure. With compromised root systems, cool season rough/fairways and putting greens (especially those being maintained very aggressively in regards to cutting height and rolling practices) did not have a chance once the excessive heat and humidity set in thus it thins out, turns yellow, withers or dies.
How is 2010 that different from previous hot summers?
Eric Bickel, Golf Course Superintendent, Hallbrook Country Club, recently compiled the following to sum up the challenge of 2010.
Dew points, temperatures, wind speed, and soil temperature are the key climactic factors, which measure the stress associated with cool season grasses ability to perform its basic physiological functions (respiration, photosynthesis, evapotranspiration.) A brief summary of these factors, their critical values, and their occurrence follows for the period of June through Aug 15.
Days with highs of 90 or above 41
Days with a low temperature above 70 47
Days with a average dew point above 70 50
Days with an average wind speed of 10 mph or less 68
Days in which soil temperatures have been above 86 55
Total days in which all five of these factors occurred simultaneously over the last 20 years (i.e. # of severe root decline days)
Year 90′ 91′ 92′ 93′ 94′ 95′ 96′ 97′ 98′ 99′
# of days 5 8 1 3 2 14 5 10 12 17*
Year 00′ 01′ 02′ 03′ 04′ 05′ 06′ 07′ 08′ 09′
# of days 9 16 13 9 5 7 11 8 5 6
*1999 had the most consecutive days with 17
When all five of these factors occur simultaneously at their critical values (highs and lows above 90 and 70 respectively, dew points above 70, soil temps above 86, and wind speed below 10) cool season grasses are in a state of full blown decline. There is no recovery for that day. The plant can no longer perform its basic functions normally. Metabolic activity is sustained solely at the expense of the root system. When this occurs for extended periods, little can be done to alleviate the issue.
To date we are at 32 consecutive days and the end is not in sight!
In six weeks when we have the first cool spell, the grass will have started healing and the reseeded areas will be showing signs of new growth. Remember who kept the courses alive in the extreme summer in the last two decades, the heroes known as the golf course superintendents. Your courses superintendent and their staff are under a huge amount of stress, show your support with encouragement, and stay educated.