New St. Augustine hybrid promises better drought tolerance
St. Augustine grass is lush, emerald green, soft to bare feet and grows in light shade. It also has a reputation for being a water hog.
Just in time, researchers at Texas A&M AgriLife Research and Extension Center at Dallas have developed a new strain of drought-tolerant St. Augustine.
The grass, known as DALSA 0605, is being cultivated by wholesale growers around the state and will be ready for sale next year, says John Cosper, executive director of the Turfgrass Producers of Texas.
It took the turfgrass team at the research center almost a decade and more than 8,000 tries before hitting on a cross that withstands drought and cold North Texas winters and still likes shade, says Dr. Ambika Chandra, one of the research team’s leaders.
With little or no watering over the drought-level summers, the new St. Augustine hybrid turned brown but then came back bright green when it rained, Chandra says.
“Water is always a big issue. If you have a grass that can survive a drought and come back, you have something,” Cosper says.
The final product crosses the familiar Raleigh strain and Floratam, a type produced by Florida research stations and A&M. Raleigh isn’t particularly drought-tolerant and Floratam doesn’t tolerate the possible lows of North Texas winters.
Crossing the two was a lot like supervising a surrogate pregnancy. “One parent of 0605 is fertile; the other parent is sterile,” Chandra says. “The embryo will start to form, but it will never produce a viable plant.”
Three weeks after pollination, technicians go out into the grass fields and harvest the embryos. They are embedded in nutrient-rich tissue until they form healthy plants, Chandra says. The new hybrid then reproduces by sending out runners.
In 2011, Chandra had fields of DALSA 0605 that “she pretty much abandoned,” Cosper says. Last summer the fields went eight weeks without rain. The plants went dormant and became brown.
“Then when it rained, it came back better than anything out there,” Cosper says.
The hybrid also survived cold winters. “It was covered with ice sheets twice this winter” and, still, DALSA 0605 greened up in the spring, Chandra says.