Dave Kopec places a blade of grass between his teeth while he contemplates a question from a visitor to the University of Arizona's Karsten Turfgrass Research Facility. The guest is asking about the care and feeding of turf, the kind that carpets golf courses throughout the Southwest, including Tucson.
Kopec, a turfgrass specialist at the UA College of Agriculture and Life Sciences, grew up decades ago in New York City public housing, where signs implored him and his friends to stay off the grass. As it turns out, Kopec has spent his life doing anything but that.
Recently, Kopec has been on the hunt for a type of grass that will stay green longer than those now in use. That is, he has been looking for a type of turf that will retain its color into December, so golf courses and other sports facilities might not have to overseed in the fall.
"This way the (golf course) superintendents would have a green surface that avoids overseeding the Bermuda grass in the fall," Kopec says. "That’s the time of year they have to slow down the Bermuda grass, prepare it to receive seed, put rye grass on top of it, germinate it, and have a growing period when you can’t walk on it. So there’s down time."
Kopec strolls across a patchwork of 36-square-foot sodded squares, each an experimental plot containing a specific species or experimental line of grass. Half the squares are the color of straw; the others are assorted shades of green. This is the grasses’ third year at the station, with two years to go.
"The straw-colored ones are the predominant grass we use in the summertime," Kopec says. "They’re asleep this time of the year when the temperatures drop below 50 at night, and below 40, and lately below 30. They turn to straw color because the leafs have stopped photosynthesizing, and the sugars inside the leaves turn to starch. People think these grasses are dead, but they’re not."
Kopec gestures toward two of the squares, both the color of sage. "These are Zoysia grasses," he says.
So far, the Zoysia, which originates from East Asia and the South Pacific, is staying greener longer than most of the station’s Bermuda grasses. What’s more, these same grasses are being tested in a half-dozen other locations to give researchers more information about where the grasses do best.
"If we could find a grass that lasts into December and goes to sleep at that point, we would only have four to six weeks of down time, especially in the Phoenix area, where it’s warmer and these grasses could be green 48 weeks of the year," Kopec says. "So far, some of the grasses are holding their color even after the very low temperatures in the 20s during the last five days. So, if we had a grass that stayed green for 46-48 weeks of the year, that might be an attractive alternative to overseeding."
Overseeding is costly, time consuming and labor intensive.
Wally Dowe knows firsthand about that. Dowe is director of golf course maintenance at The Lodge at Ventana Canyon.
"If someone could create or find a grass that did not require winter overseeding, it would greatly save facilities money and resources as well as water," Dowe says.
"A general cost for us is somewhere in the neighborhood of $250,000 to $300,000, and that includes rye-grass seed, the labor and water. And if you took into account the (lost) revenue because we obviously have to close, that could probably add another $75,000 to $100,000."
The Karsten facility is recognized by the U.S. Department of Agriculture's National Turf grass Evaluation Program, or NTEP, which sponsors trials for different species across the country. Tests last five or six years because the grasses have to be established and tested to see if they can tolerate the constant mowing stress and diseases that can develop. These effects typically don’t show up for three or four years, Kopec says.
"Also, they’re a perennial crop, so you can’t look at them for just one year to figure out if something is going to work," he says. "These tests are designed to address the needs of using less water under very special soil and weather conditions for the people who grow turf in Arizona."