climate

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.

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?

I had a conversation with Eric Watkins about the WinterTurf project. We discussed Hokkaido in northern Japan, where there is snow cover every winter. From past visits, I knew that snow cover usually starts in November, sometimes as late as December, and that it lasts until March or April.

I’ll start with a tautology. Warm-season grass species grow, and are used as turfgrasses, in locations with warm temperatures. Where it gets interesting is the interaction of light—specifically the photosynthetically active radiation (PAR)—with temperature, and with water supply or drought stress.

I made a Global DLI app to generate summary charts of DLI for anywhere in the world. This app uses the nasapower R package to get satellite data from the NASA POWER Agroclimatology dataset.

Andrew McDaniel asked me if day length or temperature has a bigger effect on zoysiagrass going into or coming out of dormancy. I hadn’t really thought about that before. When I did think about it, I realized I pretty much only think of temperature, but I wondered if living in a tropical location where the grass doesn’t go dormant might be blinding me to something that happens where day length varies.

I made a note a couple months ago to make animated charts showing the cool-season (C3) and warm-season (C4) turfgrass growth potential over a 100+ year period for Tokyo. I was interested to see what those charts would look like.

I’ve written before about the environmental productivity index (EPI), the growth potential, and nutrients. Park Nobel’s EPI “incorporates simultaneous effects of water, temperature, PAR [photosynthetically active radiation], and even nutrients” to predict the productivity, or the rate of generation of biomass.

I’ve been asked about zoysia suitability for California, particularly northern parts of California, many times. Every time, I give the same answer. In such a relatively cool climate, and in such a relatively sunny and dry climate, Cynodon seems like a much better choice.

James Faust and Joanne Logan wrote a review of daily light integral (DLI) in the September issue of HortScience. They have also prepared high resolution maps of the United States. If you click on a location on the map, a table and chart will display with the average annual and monthly DLI.