Using Growing Degree Days For Application Timing
Timing is everything, and even George Carlin had a six minute bit for it. Timing and planning go hand-in-hand for the crucial applications turf managers make throughout the season. So much of what we do is dictated by what the soil or air temperatures are for any given time. Think about how small the window is when it is time for that spring seed head suppression application. In 2016, it went from winter to spring in early March within a matter of days!
Proper planning for these events, with product in the barn ahead of time, is what makes these applications a much more seamless event. Paying close attention to growing degree days (GDD) for timing with earlier applications sets up great success for the remaining year. Presently, Cincinnati is at 932 with a base of 32.
- Ethephon / PGR 113 applications are first, with some managers trying late season and dormant apps. Presently, the seed head flush is throughout Kentucky and moving into Southern Ohio.
- Prodiamine applications tend to be early spring, and split apps seem to control weed populations better. Dithiopyr can be slightly later due to its post-emergent capabilities. Crabgrass germination is moving into extreme southern parts of Ohio as well.
- Black turfgrass ataenius (BTA) are presently in their first generation of egg laying in Southern Ohio, second generation occurs at 1200 GDD. With the newer types of insecticides in the market, season long control of BTA, white grub, and annual bluegrass weevil (ABW) can be attained with creative applications to remain in label.
- Snow mold applications vary from latitudes. In the transition zone, they are infrequent, but in northern lake-effect areas they are crucial. Better chemistry has evolved to assist the turf manager in these apps.
The information for GDD can be found here. It will provide you with dates for optimal application of these products. Remember that this is only part of the plan. A solid and balanced fertility program with sound cultural practices will allow for these timed applications to benefit your golf course!
Have a great spring!
ATS Sales Representative