Summer has finally arrived in the upper Midwest and not a day too soon considering next week is the official beginning of fall.  A few consecutive days of above average temperature and humidity took more than one course by surprise, especially courses lulled to sleep by the unusually mild summer weather. 

On one hand, the warm September weather has been a blessing at facilities struggling to maintain consistent cash flow this season.  A fair number of unanticipated green fees and cart fees are a bonus, providing optimism that perhaps the downturn of the golf industry has bottomed out and beginning to recover.

On the other hand, a short, but significant, stretch of heat and moisture stress during September could not have come at a worse time at golf courses in the process of hollow tine cultivation operations. The need to increase irrigation after aeration was easily overlooked because so little water had been applied to greens throughout the mild summer weather.  Greens full of holes, even holes that are filled with sand, are highly susceptible to moisture stress due to the increased surface area for evaporation.  The combined effect of moisture stress and the abrasion caused by the process of dragging sand into cultivation holes caused injury to localized areas of turf on greens at some courses, especially greens with a high percentage of Poa annua.

A surge of dollar spot activity has been a late season concern associated with warm September weather as well.  The sluggish golf economy has forced many courses to tighten their belts with respect to all maintenance operations including applications of plant protectants.  Do you pull the trigger on an expensive fairway fungicide treatment or hope for more favorable weather conditions that naturally suppress the disease and encourage turf recovery before winter?  After all, no one wants to end the season in a weakened condition that may increase the susceptibility of turf to winter injury. 

There is hope on the horizon regarding the decision making process for dollar spot control.  Turf researchers at the University of Wisconsin are developing a weather-based model that can predict the outbreak of dollar spot disease.  Documenting the need to apply fungicides and other plant protectants will become increasingly important as environmental restrictions become more stringent. 

Stay tuned to this USGA channel for future monthly updates that discuss this research in more detail.  In the meantime, enjoy the warm weather.        

Source: Bob Vavrek, rvavrek@usga.org or 262-797-8743