temperature

Many golf course superintendents around the world manage creeping bentgrass greens for some portion of the year in what we could call tropical conditions. One of the places where summers have tropical heat, and where there are a lot of bentgrass greens, is Japan.

The PACE Turf temperature-based growth potential, or GP, is a utility function that takes the input of average air temperature, and gives an output of GP on a scale of 0 to 1, or 0 to 100%.

I’ve written before about ΔGP. That’s read as “delta G P” and it is the difference in the cool-season and the warm-season growth potential. Specifically, it is the cool-season GP first, then the warm-season GP is subtracted from that.

You may have seen the maps of monthly growth potential through the seasons from PACE Turf. Those animated maps take the average temperature, convert it to a growth potential, and then color code a map of the USA with that animation.

I’ve been getting a lot of questions about the turf GvX. And I’ve been checking my calculations to make sure I’ve got a somewhat standardized method to get the GvX number for any day.

I made my first visit to Myrtle Beach two weeks ago for a seminar with the Palmetto GCSA at Horry-Georgetown Technical College. I knew there were a lot of golf courses in the Myrtle Beach area, but until I visited in April and saw all the ryegrass, I didn’t realize that so many courses there overseed in the autumn.

Figure 1. The snow-covered landscape of central Hokkaido in mid-March 2024 when the growth potential was 0 but the DLI was fine. In a recent ATC Doublecut discussing light and temperature, I mentioned that I’d calculate potential DLI for the recording location, check the actual DLI for the recording location, and share that information.

I sometimes talk about maximum N. You may have heard me refer to the standard amount of N. I discussed that with Michael Bekken in this ATC Doublecut episode. What do I mean by these quantities of N?

Randy from Bulgaria sent me this interesting question, which I paraphrase here: I was wondering is there a place on earth, where growth potential (GP) is above 90% for cool-season grass, or also a place where GP is above 90% for warm-season grass, all year long?

For any day in the year, one can calculate the cool-season grass growth potential (GPC3) and the warm-season grass growth potential (GPC4). These growth potential functions take the average air temperature as the input and return a GP value on a scale of 0 to 1, or 0 to 100% if you prefer.