Oklahoma State University’s (OSU) Tahoma 31 turfgrass has become a staple, not only for lawns such as the U.S. Capitol Lawn in Washington, D.C., but also at major sports venues around the world, from Dodger Stadium and Churchill Downs to the Philadelphia Eagles and Kansas City Chiefs football stadiums.
Portions of this story were originally published by OSU Agricultural Communications and are reprinted here with permission.
Now add Super Bowl LVII to that list. When the Kansas City Chiefs and the Philadelphia Eagles take the field Sunday in Glendale, Arizona, they will be on familiar turf. Exactly one million pounds of Tahoma 31 was grown for the Super Bowl. The variety was developed by OSU researchers with support from USDA’s National Institute of Food and Agriculture.
“This is a great example of how the availability of long-term funding allows advances that truly make a difference,” said Tom Bewick, national program leader who oversees NIFA’s Specialty Crop Research Initiative (SCRI) grant program. The OSU turfgrass research team has collaborated on three multi-institute SCRI grants totaling more than $16 million in support of the development of turfgrass.
Turfgrass is used on more than 700,000 athletic fields across the nation, according to the National Turfgrass Federation. The turfgrass industry contributes more than $40 billion per year to the U.S. economy, according to USDA’s Economic Research Service.
Developing Tahoma 31
Tahoma 31 derives its name from the Native American word Tahoma, which means frozen water. In test after test, Tahoma 31 showed exceptional winter hardiness and tested up to 75% more cold tolerant than other Bermudagrass varieties.
The drought tolerance and shorter root zone observed in controlled and environmental trials of Tahoma 31 make it a smart choice for residential lawns, especially the yards of new home construction where equipment tends to remove much of the topsoil. Sod producers also value Tahoma 31 for its ability to remain intact after being harvested and transported.
“Tahoma 31 is definitely the most cold-tolerant variety ever released commercially,” said Chad Adcock, vice president of business development at Sod Production Services, which exclusively licenses the variety.
The OSU turf was planted at around 30 sod farms nationally in its first year of commercial availability. Adcock said two years are required for a single farm to achieve production levels before the grass is ready for retail and can begin attracting a customer base.
Lakshmy Gopinath is a postdoctoral researcher in the Department of Horticulture and Landscape Architecture who studies the sod tensile strength, handling quality and divot recovery of Tahoma 31. Her trials show it recovers quickly after the winter season, a type of turf in high demand among golf courses.
“Of all the variety plots, Tahoma 31 was the first to show green as early as March 12, and it can be mowed at really low heights,” she said.
Now in its third year of production, Tahoma 31 is beginning to spread to fields and courses locally and beyond. It is installed at more than 50 golf courses, football fields, soccer complexes and baseball parks.
“We are completely ecstatic with the results we’ve had from end users and growers who are involved with Tahoma 31, and we are super excited about its future,” Adcock said.
True to the stellar reputation of OSU’s turfgrass breeding and development program and its affiliated departments within the Ferguson College of Agriculture, faculty, staff and students aren’t stopping with Tahoma 31. The turf industry can expect a new OSU variety within the next several years to continue enhancing athletic facilities, home lawns and golf courses around the globe.
Developing Quality Turfgrass
The Bermudagrass variety Tahoma 31 is a great example of the extensive testing and the experience needed to develop quality turfgrass. When the Bermudagrass growing season, usually April - October, comes to a close, OSU scientists turn to lab and greenhouse testing over the winter months to make the best use of time in testing new experimental varieties.
This research process has taken place almost every year at OSU since the mid-1900s. Traditionally the entire process for the release of a new variety of turfgrass has been 10 to 15 years and requires an extensive greenhouse, lab and field screening and a testing process that can include more than 1,000 experimental plants.
This lengthy stretch of time between the start of studying an experimental line and it going to commercial market is because there are many steps and processes that must happen to ensure OSU is releasing the highest quality of turfgrass varieties.
Genetic attributes in Bermudagrass are studied at the same time experimental lines are being created, which helps in the selection process of current and future lines. Features are studied and lines are tested to determine what causes desired attributes in turfgrass, such as cold hardiness and drought resistance. Then breeding turfgrasses to obtain those genetic traits begins.
Scientists must then study these bred varieties over the course of several years to determine if they have the quality and traits to make them viable for the commercial market. From there, licensing with producers and private industry occurs. At this stage, it can take two to four years for the turfgrass to be widely available in the commercial market for purchase.
“A variety can fail at any point in the chain and a variety can even fail once it has been released to the market,” said Dr. Yanqi Wu, OSU plant and soil sciences professor and plant breeder. “Breeding and development is a very high-risk venture and success is not guaranteed even with significant expenditure of time and funds.”
Thousands of Experimental Lines
Wu said with his team working on thousands of experimental lines each year, new turf Bermudagrass varieties are usually released once every several years. The research involving the two most recent varieties being released, including Tahoma 31, involved around 9,000 experimental plants.
"After initial evaluation, the breeder will select around 20 to 30 plants to be sent to collaborators across the U.S. to evaluate sod tensile strength, freeze tolerance, drought resistance, traffic tolerance, shade tolerance, disease resistance, golf ball roll distance and so on,” Wu said. “Every five years, the development team will submit two to 10 of their best selections to the National Turfgrass Evaluation Program where around 10 to 20 university scientists around the country will evaluate turfgrass performance and adaptation.”
The information gained from national testing is used to decide whether to release the experimental varieties to the public, and if so, to secure proprietary protection in the form of U.S. Plant Patents or Plant Variety Protection Certificates.
With a lot of hard work, a great deal of testing and some setbacks, scientists find the variety with the right genetic makeup to have strong color, durability, drought resistance, cold hardiness and more.
Genetic Markers Lead the Way
OSU scientists continuously pursue their molecular research on the two parent species, African Bermudagrass and common Bermudagrass, using DNA markers to study the genetic inheritance of important traits.
“We have developed most of the molecular marker tools in the world for Bermudagrass,” Wu said.
With these tools, scientists map the genomes of different Bermudagrass varieties, and improved varieties of turfgrass are created.
“We have already developed more than 3,000 genetic markers, but there is more work to do,” Wu said. “It is all about little steps moving forward then combining all of those little steps to make larger progress.”
Wu said the research is a collaboration among OSU scientists, graduate students and technicians, as well as scientists from other universities. “We want to always work toward better water conservation and water-use efficiency regarding grasses and sustainability traits,” Wu said.
Wu predicts the industry could probably save millions of dollars if more facilities used cold-hardy and water-use efficient grasses. “I think our work has really produced some national impact. OSU grasses have been used in many places, and we are proud of that,” Wu said.