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Bermudagrass has long been the grass species of choice for lawns, golf courses, sports fields and pastures in the South. It thrives in warm climates, is relatively tolerant of drought and low mowing heights, and grows vigorously – properties that make it valuable for golf. In fact, there is more bermudagrass on golf courses in the U.S. than any other grass species (Shaddox et al., 2023). This article traces the remarkable development of important bermudagrass cultivars, both past and present. Behind the introduction of each new cultivar may be found the efforts of many talented scientists who have provided basic genetic information, collected grasses from around the world, and developed better selection and breeding methods.

Dr. Glen Burton and the Early Years

Bermudagrass (Cynodon dactylon) did not arrive in North America until the 18th century, and is believed to have come from Africa, India or via Spanish colonists. By the early 20th century, some level of bermudagrass management on golf courses was ongoing, but formal breeding efforts didn’t take shape until the 1930s.

In 1936, Dr. Glen Burton, a dedicated researcher and plant breeder, laid the cornerstone for his groundbreaking endeavors over the next five decades. Burton set turfgrass science in the U.S. on a journey that would transform golf courses and sports fields in the South and beyond. Burton’s influence during his career was far-reaching. For all his work in turfgrass, his research to increase crop yields in pearl millet ultimately fed millions of people in developing countries worldwide, earning him notoriety and the National Medal of Science from President Reagan.

In the late 1930s, Burton began breeding forage bermudagrasses at the USDA’s Coastal Plain Experiment Station in Tifton, Georgia. He began with several promising fine-leafed bermudagrass selections collected from Savannah Golf Club in Georgia. By 1946, bermudagrass breeding at the Tifton Station, under Burton’s direction, had caught the attention of the USGA and the United States Department of Agriculture (USDA). Their recognition and financial support marked a significant milestone in developing this versatile grass.  

In 1947, USDA scientists selected ‘U-3’ bermudagrass from the Savannah Golf Club collection. ‘U-3’ had fine texture, spread rapidly, was cold tolerant, and showed durability across various soil and climatic conditions. The tireless efforts of researchers like Dr. Fred Grau, director of the USGA Green Section, played a pivotal role in the 1957 release of ‘U-3’ by the USDA and the USGA.

Tifton Station Hits Its Stride

The year 1956 brought Burton’s release of ‘Tifgreen 328’ (often referred to today as simply ‘Tifgreen’ or ‘328’) through the USDA and Georgia Agriculture Experiment Station. ‘Tifgreen’ is a hybrid bermudagrass created by crossing an African diploid variety (Cynodon transvaalensis) with a robust common variety. The resulting hybrids are sterile – therefore, sod, plugs, or sprigs vegetatively establish ‘Tifgreen’, not seed. This marked a shift in how most bermudagrass playing surfaces would be established on golf courses. ‘Tifgreen’ found its home on putting greens, while its sibling ‘Tiffine’ flourished as an improved lawn variety. The drawback of ‘Tifgreen’ was its tendency to mutate genetically, creating new and varied plants, most with unappealing characteristics for putting greens. As we’ll discuss later, its fondness for mutating eventually became its legacy.

Two other notable varieties of the 1950s were ‘Sunturf’, a natural hybrid from South Africa released in 1956 by Alabama, Arkansas, Oklahoma and South Carolina Agricultural Experiment Stations, and ‘Texturf 10’, released by the Texas Agricultural Experiment Station in 1957.

The Sixties: One Small Step for Man, One Giant Leap for Bermudagrass Breeding

The 1960s brought many new varieties of notably higher quality to market, many still in use today. The release of ‘Santa Ana’ in 1966 resulted from over a decade of work by Dr. Victor Youngner, who was a plant breeder for Ferry-Morse Seed Company before accepting a position in 1955 at UCLA. There, he made the initial hybrid selections leading to ‘Santa Ana’ from common bermudagrass plants and ‘Royal Cape’, an African bermudagrass.

Youngner transferred to the University of California, Riverside (UC Riverside) in 1965, where he coordinated the 1966 release of ‘Santa Ana’ through the California Agricultural Experiment Station. The variety is known for its deep blue-green color, medium-fine texture, good fall color retention, and salt tolerance. Interestingly, it also has a high degree of tolerance to smog, which frequently discolored ‘Tifway’ and ‘Tifgreen’. ‘Santa Ana’ raised the bar significantly regarding desirable bermudagrass traits and is a testament to the fact that quality turf breeding takes time – with the initial selections taking place 11 years before it was released. ‘Santa Ana’ remains a popular grass choice for California golf course fairways and athletic fields.

Two additional landmark moments in bermudagrass breeding occurred in the 1960s, the first being Burton’s release of ‘Tifway 419’. Explicitly designed for golf course fairways, this versatile grass quickly became the go-to choice for golf course roughs, lawns and sports fields in warm climates across the country. At the same time, James Moncrief, director of the USGA Green Section’s Southeast Region, was collecting naturally occurring mutations of ‘Tifgreen’ that ultimately became ‘Tifdwarf’. Released in 1965, ‘Tifdwarf’ is one of the most important grasses of its era and possessed a never-before-seen tolerance of low mowing heights. As we’ll discuss later, additional selections of ‘Tifgreen’ mutations gave rise to the “ultradwarfs” in the 1990s.

Throughout the 1960s, work began to advance the understanding of bermudagrass biology. An example is the efforts of Drs. Jack Harlan, J.M.J de Wet and Wayne Huffine, who traveled worldwide to collect more than 700 bermudagrass genotypes that were then maintained at Oklahoma State University. From 1963 to 1967, these renowned botanists and agronomists classified the collection morphologically and cytologically, and tested their “crossability” in hybridization studies. The work resulted in a revision of the genus Cynodon and an analysis of the genetic relationship between the species.

Although the 1970s were a relatively quiet time in bermudagrass breeding, many new and talented scientists were being trained or beginning their careers. Renowned breeders like Dr. Charles Taliaferro at Oklahoma State, Dr. Wayne Hanna at Tifton Station, and Dr. Arden Baltensperger at New Mexico State began to devote more attention to bermudagrass breeding. This next generation of scientists were waiting in the wings when the golf boom of the 1980s hit, bringing with it a surge in golf course construction and a renewed interest in improved bermudagrass varieties.

The Golf Boom

The 1980s saw the arrival of several vegetative and seeded bermudagrass cultivars to meet golf’s growing needs. At Tifton Station, Hanna and Burton released ‘Tifway II’ in 1981. Tolerant of heavy traffic, drought and poor water quality, ‘Tifway II’ also has improved resistance to sting, root-knot and ring nematodes.

Meanwhile, Taliaferro at Oklahoma State released ‘Guymon’ in 1982, a seeded cold-hardy common bermudagrass. Before ‘Guymon’, common bermudagrass seed production was primarily conducted along the Colorado River near Yuma, Arizona, and the Imperial Valley of California. However, Taliaferro turned to Johnston Seed Company in Enid, Oklahoma, to produce ‘Guymon’ since flowering habit and seed yields for the cultivar were better in Oklahoma.

Also of note was the USGA Green Section’s dramatic increase in its support of university research in 1984, from which bermudagrass breeding projects benefited greatly. In 1986, Taliaferro received a USGA grant to develop cold-hardy bermudagrass cultivars and further enhance the adaptability of the grass. USGA funding also led to the release of the seeded variety ‘NuMex Sahara’ in 1988. The release of ‘NuMex Sahara’ marked the culmination of a 20-year breeding effort by Baltensperger at New Mexico State. As we mentioned earlier, breeding quality turfgrass takes time.

It’s worth noting that the National Turfgrass Evaluation Program (NTEP) trials for bermudagrass kicked off in the 1980s. The first trial in 1986 had 28 entries, including several cultivars mentioned above. In 1997, NTEP combined efforts with the USGA and others to evaluate bermudagrass putting green cultivars on golf course practice greens, which provides more meaningful data on how varieties perform under different maintenance regimes. Today, NTEP continues to provide golf course superintendents with valuable information about how different bermudagrass varieties perform under a wide range of maintenance levels and in various locations and climates.

The Ultradwarf Revolution

The “ultradwarfs” are what most superintendents and golfers today think of when it comes to bermudagrass putting greens, and their roots can be traced back to the 1956 release of ‘Tifgreen’. Recall that ‘Tifdwarf’ was identified as a promising mutation in stands of ‘Tifgreen’ due to its darker color and low growth habit. Later, natural or induced mutations in ‘Tifdwarf’ became the basis for the ultradwarf bermudagrasses. Essentially, the ultradwarfs are the “grandkids” of ‘Tifgreen’.

The 1990s saw the introduction of several new ultradwarf varieties for putting greens, almost all of which are still in use today. ‘MiniVerde’ and ‘Champion’ were selections from naturally occurring mutations in ‘Tifgreen’. What breeders early on viewed as the biggest liability of ‘Tifgreen’ – its tendency to produce mutations (off-types) – became its lasting legacy in the form of the ultradwarfs.

In 1986, Dr. Burton observed that: “The occurrence of the natural mutant ‘Tifdwarf’ and the finding of other probable mutants in ‘Tifgreen’, indicate to us that we might speed up this natural mutation process by treatment with mutagenic agents.” Burton’s theory proved correct. In 1988, at Tifton Station, Hanna initiated the development of ‘TifEagle’ by exposing ‘Tifway II’ stolons to Cobalt 60 gamma radiation. ‘TifEagle’ took the stage in 1997 with an excellent root system, high-quality surface, and low cutting height for putting greens.

Hanna’s efforts bore fruit again in 1996 with the release of ‘TifSport’, celebrated for its superior color, improved cold-hardiness, and disease resistance, especially at lower mowing heights. ‘Tift 94’ is another bermudagrass Hanna created, this time by exposing ‘Midiron’ stolons to Cobalt 60 gamma radiation.

Breeding Cold-Tolerant Bermudagrasses

One of most important traits of bermudagrass for golf course superintendents in the transition zone is cold tolerance, which was recognized early on by breeders. In 1957, cold-hardy bermudagrasses were selected from North Platte, Nebraska, by Harold Haekrott. These selections were used by Dr. Ray Keen, professor of ornamental horticulture at Kansas State, to develop more cold-tolerant plants, which led to the release of ‘Midiron’ in 1969. Work by Keen and others meant bermudagrass could be reliably planted as far north as Maryland, and scientists from the USDA noted this transition zone cultivar’s excellent winter hardiness, persistence and lack of spring dead spot disease.

After completing his Ph.D. on freeze tolerance of citrus at the University of Florida, Jeff Anderson started working on new techniques to conduct controlled growth chamber experiments on the low-temperature tolerance of various bermudagrasses. Anderson measured electrical conductivity, which indicated whether plant cells had burst due to cold. This screening technique helped estimate cold hardiness and gave better guidance on grass selection and maintenance to golf course superintendents. For example, ‘Champion’ cells burst at 23 degrees F compared to ‘Midlawn’ at 17 F.

The 1990s brought Dr. Dennis Martin to Oklahoma State, where in 1991, they released the cold-hardy vegetative varieties ‘Midlawn’ and ‘Midway’ in collaboration with Kansas State. Keen originally developed both cultivars during the 1960s and maintained them in plots at Kansas State. Both did well in the 1986 NTEP bermudagrass tests, but they had poor sod strength, so establishment by sprigs or the use of netting was necessary.

Another milepost on the highway of bermudagrass breeding was placed in 1996, when Dr. Mike Anderson and graduate student Mark Gatschet, along with Taliaferro and Anderson, conducted breakthrough molecular research on cold-regulated proteins that impact bermudagrass cold tolerance. This work gave insight into the plant’s response to low temperatures, and in 2002, Taliaferro – still hard at work at Oklahoma State – made excellent progress in low-temperature tolerance with the release of ‘Patriot’, the first cold-hardy, vegetative hybrid bermudagrass with excellent sod production tailored specifically for golf course fairways and sports turf.

Continuing advancements in 2010, Martin and his colleague Dr. Yanqi Wu introduced ‘Latitude 36’ and ‘Northbridge’. This second generation of vegetative, cold-tolerant bermudagrasses pushed the geographical limits of bermudagrass farther north than ever before. In 2019, Martin and Wu hit another milestone with the release of ‘Tahoma 31’ from Oklahoma State. This new cultivar boasts superior cold tolerance and improved water conservation, opening even more possibilities for bermudagrass in the upper transition zone.

Expanding bermudagrass into regions with colder winters will be a focus of future breeding efforts. Superintendents in the transition zone need grasses that can tolerate increasingly hotter summers so that golfers have the best playing surface possible when it matters most. Still, they also need grasses that can withstand freezing temperatures in the offseason. Even in areas with moderate winters, off-season color retention and playability have become increasingly important, especially with courses busier than ever in winter and a growing desire to move away from overseeding to conserve water and improve year-round playing conditions.

A New Generation of Breeders, A New Set of Challenges

The journey of improving bermudagrasses continues with the current generation of turfgrass breeders. Research today focuses on developing grasses that play better and have improved tolerance to things like drought, cold, shade and salinity.

The new generation stands on the shoulders of all the breeders of the past, but in many cases, they worked alongside them as well. Scientists like Dr. Kevin Kenworthy, a graduate of Oklahoma State under Taliaferro, trained with the legendary breeder and joined the University of Florida to focus on breeding warm-season grasses for the state’s unique climate. Also in the 2000s, the University of Georgia hired his Ph.D. student Brian Schwartz to work alongside Hanna and continue the warm-season turfgrass breeding efforts pioneered by Burton at Tifton Station.

In 2010, a talented young scientist named Dr. Ambika Chandra at Texas A&M, was chosen to lead a USDA Specialty Crop Research Initiative (SCRI) $3.8 million grant awarded to five universities. The cooperating universities included Florida, Georgia, NC State, Oklahoma State and Texas A&M. The SCRI grant allowed more than twenty university faculty across several disciplines to evaluate large nurseries of warm-season grasses at several locations in the U.S. This effort has received more than $10 million in grants since the original 2010 project and continues today at the universities mentioned above along with UC Riverside and the University of Tennessee.

The fondness bermudagrass has for mutating, while sometimes frustrating for golf course superintendents, is also a source of new genetic material – something Burton took advantage of and is necessary for breeders to make progress improving any grass. Two major focal points of current breeding efforts that will only become more important in the future are improving cold and drought tolerance. Although these needs sometimes intersect, it also highlights the various qualities that bermudagrass can offer to superintendents in a broad geographical range.

In 2008, when UC Riverside hired Dr. James Baird amid historic drought in California, he quickly got to work with geneticist Dr. Adam Lukaszewski (and later with fellow breeder Dr. Marta Pudzianowska) to breed drought-tolerant bermudagrasses. Two cultivars stood out from a nursery of 400 hybrids subjected to more than 40 days without water. These new hybrid bermudagrasses, ‘Presidio’ (formerly UCR 17-8) and ‘Coachella’ (formerly UCR TP6-3), should be commercially available by 2026.

In 2016, a crowning achievement arrived when Schwartz and Hanna at Tifton Station released ‘TifTuf’. The grass, meticulously developed by Hanna in 1992, underwent rigorous scientific testing at the University of Georgia. ‘TifTuf’ demonstrated significant water conservation, with greater than 30% savings compared to ‘Tifway’. It’s important to note that this was the first nationwide trial of its kind ever conducted on bermudagrass. The future of bermudagrass in the golf world will include substantial contributions to water conservation and resource management.  

"The future of bermudagrass in the golf world will include substantial contributions to water conservation and resource management."

To further investigate the ability of bermudagrass to tolerate drought, the USGA and NTEP initiated a trial measuring the water requirements of warm-season grasses subjected to drought in 2019. The key takeaway was that newer cultivars like ‘TifTuf’ and ‘Tahoma 31’ require less water than most older varieties and that bermudagrasses generally outperform zoysiagrass and buffalograss during drought – further demonstrating the ability of the species to help with water conservation efforts, especially when not overseeded.

Final Thoughts

Bermudagrass’ journey from 1936 to the present has been one of dedication, innovation and continuous improvement. The efforts of all the breeders mentioned in this article, support staff and countless others behind the scenes, have transformed golf courses, sports fields and lawns around the globe. Bermudagrass will continue to play a vital role in conserving water, reducing the use of critical resources and bringing new grass choices to golf courses in colder climates. The remarkable diversity of the species Dr. Glen Burton grasped hold of nearly a century ago is the key to its future.

Reference

Shaddox, T. W., Unruh, J. B., Johnson, M. E., Brown, C. D., & Stacey, G. (2023). Turfgrass use on U.S. golf courses. HortTechnology, 33(4), 367-376.  https://doi.org/10.21273/HORTTECH05238-23