Illustration: Ryan Farrell, Research Communications

Any homeowner who wants a beautiful lawn knows, St. Augustine grass has many virtues—and one major vice.

On the plus side, the popular turfgrass produces a thick carpet of blue-green blades that overwhelm weeds and other grasses.

But there is a significant downside.

Ambika Chandra

“Consumers often think of St. Augustine as a water hog,” says Ambika Chandra, professor in the College of Agriculture and Life Sciences as well as a turfgrass breeder with Texas A&M AgriLife Research in Dallas.

That’s because St. Augustine requires at least a half-inch more water per week than its competitors in the nation’s $1.1 billion market for natural grass sod.

But there’s good news for St. Augustine: Chandra and her AgriLife turfgrass team have launched a new hybrid that combines the best traits of everyday St. Augustine—but needs as little as half the water.

Texas A&M AgriLife team members (from left) are Chrissie Segars, Ambika Chandra and Justin Eads testing the strength of Cobalt in 2019.

Texas A&M AgriLife Marketing and Communications photo by Gabe Saldana

“This is the most drought-resistant St. Augustine variety on the market,” says Tobey Wagner, founder and CEO of Sod Solutions, the South Carolina company that licensed the hybrid from The Texas A&M University System and markets it under the brand name Cobalt. “It’s also resilient to insects and disease, so you don’t have to use as much insecticide or fungicide to keep it healthy. That’s a huge advantage.”

Cobalt also has attracted the attention of the state’s sod growers, says Brent Batchelor, executive director of Turfgrass Producers of Texas, the industry association that represents 70 companies that operate 100 Texas sod farms.

“There hasn’t been a new St. Augustine grass in a long, long time,” Batchelor says. “Cobalt has the traits sod growers are looking for, especially the tolerance to drought.”

What’s more, Cobalt produces a wider blade in a richer shade of green than other St. Augustine varieties. It also grows well in the shade and can survive in colder climates.

“Cobalt is something special,” Sod Solutions’ CEO Wagner says. “But it took a long time to get to this point. It’s really a story of patience and perseverance.”

Cobalt produces a wider blade in a richer shade of green than other St. Augustine varieties. It also grows well in the shade.

Illustration: Ryan Farrell, Research Communications

The chromosome problem

That story began in 2003 when a group of Texas turfgrass producers approached the Texas Agricultural Experiment Station, the forerunner to Texas A&M AgriLife Research.

The producers offered to invest in developing a hybrid that would significantly improve the market for St. Augustine grass.

“The researchers surveyed the producers to identify their goals for the project,” says Chandra, who has led A&M’s turfgrass program since 2007. “Number one was drought resistance. After that came disease resistance, insect resistance and turf quality.”

Satisfying these goals required the A&M turfgrass program to develop a St. Augustine variety that nature alone would never produce.

Most plants have 18 chromosomes and are classified as “diploids.”

These diploids include the varieties of St. Augustine that are popular in the southern United States, especially Texas. These varieties tolerate shade and cold. They produce shorter blades with a finer leaf texture than other grasses. But they demand more water.

Other plants have more than 18 chromosomes and are known as “polyploids.”

“A lot of polyploid grasses come from Africa,” Chandra says. “They tend to resist drought, disease and insects. These were the traits we were looking for.”

However, these African polyploid grasses often grow much taller than diploid turfgrasses cultivated in the United States. They also produce colors other than the deep green preferred by home and business owners.

“You can think of these polyploid grasses as ‘wild types,’” Chandra said, “because they haven’t gone through the breeding process that would give them turfgrass characteristics.”

Chandra and her team wanted to cross St. Augustine diploids with these wild African polyploids. However, nature presented a huge obstacle.

For crossbreeding to succeed, each chromosome from one parent plant must pair up with a chromosome from the other parent plant. But diploids have 18 chromosomes and polyploids have more. The irregular pairings produce an embryo that cannot survive without help.

“Fertilization happens and the embryo is formed, but the endosperm—which provides nutrition to that growing embryo—does not fully develop,” Chandra says. “If you leave the embryo on the maternal parent, it will eventually die from a lack of nutrition.”

Without embryos, there was no way to produce seeds to grow a hybrid variety of St. Augustine.

To overcome this problem, Chandra and her team applied a time-tested method known as embryo-rescue technology.

About 21 days after fertilization, the turf breeders remove embryos from the mother plant and transport them to their lab. Then they nourish the embryos with sucrose, the chief component of cane sugar.

“We’ve successfully developed thousands of hybrids using embryo-rescue technology,” Chandra says. “The technology has been out there for decades, but we pioneered it for St. Augustine grass.”

Moment of truth

Starting with thousands of contenders, in 2018 the AgriLife Research team used a series of tests and trials to narrow the field to eight semifinalists.

Each semi-finalist had the traits the producers wanted. The next task was to identify which variety would produce the best sod.

In July 2020, the team planted four finalists in plots of up to 20,000 square feet at a sod farm near the South Texas town of Wharton. Almost a year later, the results came in from the sod-harvesting tests.

As leader of the turfgrass-breeding team, during a field day at the Wharton sod farm, Chandra revealed the findings to representatives from AgriLife, from the turf producers who funded the research and from Sod Solutions, which first took an interest in the project in 2018.

Chandra had a good feeling about one of the finalists, DALSA1618, which received high scores from a 2015 U.S. Department of Agriculture research initiative and the 2016 National Turfgrass Evaluation Program, where candidates underwent tests at seven universities.

“As far back as 2018,” she says, “I knew—if this grass would produce a sod with good characteristics for harvesting—we would all agree to move forward with DALSA1618 as the next commercial variety.”

Sod Solutions CEO Wagner attended the field day with his company’s executive director of research, Roberto Gurgel. As Wagner listened to Chandra go over the data, he noticed something unusual.

“Turf breeders are usually very conservative when they talk about their data and what it means,” Wagner says. “But I could tell from Chandra’s face that DALSA1618 was something special.”

Wagner also noticed that one long strip of planted turfgrass stood out from the other three.

“That strip looked as if someone had sprayed it with fungicide,” Wagner says, “because there was no sign of leaf spot. It had this beautiful dark-green color. And then Chandra started talking about the drought tolerance, the shade tolerance and the lower levels needed for insecticide and fungicide ... it was almost too good to be true.”

The newest data confirmed what Chandra suspected: Among the thousands of hybrids Chandra’s team had developed and tested over 17 years, DALSA1618 was the clear winner.

“That was the day everyone decided we would move forward with DALSA1618,” Chandra says. “That was a humbling moment for me, because I understand the strength of the genetics behind this variety. That was when I knew we would soon see the impact of our work on the market.”

Photo: Sashko / Shutterstock.com

If all goes well, Cobalt should appear on the retail market sometime in 2023.

From lab to market

It took more than a year to hammer out a three-party agreement between the A&M System, which owns the patent to DALSA1618; Sod Solutions, which licenses the patent and controls the Cobalt trademark; and Turfgrass Producers of Texas, which represents the original investors and will receive a return from sales of Cobalt.

The contract was a first for everyone, says Janie Hurley, program director for Intellectual Property & Commercialization, Texas A&M AgriLife Research.

“That was a complicated negotiation,” Hurley says. “It took a lot of work to get everyone comfortable with this arrangement. The growers had worked with AgriLife, and they’d worked with Sod Solutions, but never in a three-party agreement.”

That done, Sod Solutions is preparing to move Cobalt onto the turfgrass market.

The company is putting the hybrid through its own round of testing in Texas and Florida, the two largest U.S. markets for St. Augustine.

In addition, Sod Solutions is developing a marketing program around Cobalt that includes educational materials and tradeshow exhibits, building on the company’s long-standing relationships with turfgrass producers.

“Their team provides the boots on the ground,” Chandra says. “If there are issues, they work with our team to make sure the growers have a successful experience producing the variety for the marketplace.”

In addition to Cobalt, Sod Solutions licenses a variety of zoysia grass developed by AgriLife’s turfgrass program. Marketed under the brand name Innovation, the variety is now grown on 35 sod farms in 16 states as well as South America and Europe.

“We’re hoping that Cobalt will redefine how consumers think about St. Augustine,” says Sod Solutions CEO Wagner.

“This is a grass that solves a lot of problems.”

Ambika Chandra, AgriLife Research professor of turfgrass breeding and genetics in Dallas, delves into the development and testing of Cobalt St. Augustine grass


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