The University of Georgia (UGA) turfgrass breeding program develops improved cool- and warm-season turfgrass cultivars adapted to the environmental conditions and management challenges of the southeastern U.S. Breeding objectives focus on improving turf quality, persistence, environmental adaptation, and resistance to biotic and abiotic stresses while meeting the evolving needs of golf courses, sports fields, home lawns, sod producers, and landscape managers.
Research activities encompass a diverse collection of turfgrass species, including seashore paspalum (Paspalum vaginatum), zoysiagrass (Zoysia spp.), bermudagrass (Cynodon spp.), centipedegrass (Eremochloa ophiuroides), tall fescue (Festuca arundinacea), perennial ryegrass (Lolium perenne), Kentucky bluegrass (Poa pratensis), and fine fescues (Festuca spp.).
Together, these breeding efforts aim to develop superior cultivars capable of maintaining performance under increasingly challenging environmental and management conditions.
Seashore Paspalum
The seashore paspalum breeding program at UGA has played a leading role in the development and commercialization of improved seashore paspalum cultivars for golf course, sports field, and landscape applications. Our seashore paspalum program has announced the development of three new cultivars that are likely to have a major impact on the global turfgrass industry over the next few years.
In 2023, UGA released ‘SeaScape’ seashore paspalum, a vegetatively propagated conventional cultivar suitable for course-wide use on golf courses and on athletic fields, home lawns, and other recreation venues. Our breeding program developed the first non-GMO herbicide resistance system for seashore paspalum and branded it as ACCeTM technology.
ACCeTM technology utilizes a mutation conferring high levels of crop tolerance to several ACCase-inhibiting herbicides and provides greatly enhanced control options for weedy grasses such as bermudagrass in seashore paspalum. Utilizing our germplasm with this technology, Pure Seed Testing has recently released ‘Stratis’ with ACCeTM, an exciting new herbicide-resistant seeded paspalum marketed by Atlas Turf International. In addition, UGA developed a new vegetatively propagated cultivar with ACCeTM technology and released it in 2025. It will be marketed under the name of ‘SeaLect’ when it becomes commercially available in 2027.
Current breeding efforts focus on evaluating advanced experimental germplasm and identifying superior selections with enhanced turf quality, stress tolerance, establishment characteristics, and overall adaptation. Ongoing research seeks to expand the utility of seashore paspalum through the development of cultivars with enhanced weed control options and the capability of meeting the evolving needs of turfgrass managers while maintaining the exceptional salinity tolerance and environmental adaptability that have made seashore paspalum an increasingly important turfgrass species throughout the southeastern U.S. and beyond.
Zoysiagrass
Zoysiagrass (Zoysia spp.) is one of the most adaptable warm-season turfgrasses and is valued for its drought tolerance, shade tolerance, salinity tolerance, dense canopy, low mowing requirement, and reduced fertilizer and pesticide needs. These characteristics make zoysiagrass a strong candidate for home lawns, roadsides, parks, and other low-input turf systems. Despite these advantages, broader adoption has been limited by the cost and logistics of vegetative establishment and by the limited availability of seeded cultivars. At present, ‘Zenith’ and ‘Compadre’ are the primary commercial zoysiagrass cultivars available in seed form in the United States.
Seed-propagated zoysiagrass could provide a lower-cost and more easily distributed alternative to sod, plugs, or sprigs. However, inconsistent seed production and poor seed germination continue to restrict the development and adoption of seeded zoysiagrass.
Seed dormancy has long been recognized as a major barrier to reliable establishment, and previous studies have shown that germination may be improved through physical, chemical, or physiological seed treatments. However, treatment responses have been inconsistent, and relatively few studies have evaluated emergence across diverse zoysiagrass germplasm or determined whether treatment effects are dependent on genotype.
Understanding genotypic variation in seedling emergence is important for both cultivar development and practical turf establishment. Germplasm with rapid and sustained emergence may provide useful sources of reduced dormancy and improved seed-based establishment, while genotype-specific treatment responses may help determine whether chemical treatments such as sodium hydroxide (NaOH) or potassium hydroxide (KOH) consistently improve emergence or benefit only selected germplasm.
Recent evaluations of 28 zoysiagrass genotypes demonstrated significant variation among genotypes, seed treatments, and days after planting (Table 1).
Table 1. Model Summary for the Zoysiagrass Seedling Emergence Trial.
| Source of variation | df | ||
|---|---|---|---|
| Genotype (Geno) | 27 | χ² | P-value |
| Treatment (Treat) | 2 | 191.835 | < 0.0001 |
| DAP | 11 | 196.814 | < 0.0001 |
| Geno x Treat | 54 | 833.833 | < 0.0001 |
| Geno x DAP | 297 | 513.810 | < 0.0001 |
| Treat x DAP | 22 | 676.566 | < 0.0001 |
| Random term | Variance | |||
|---|---|---|---|---|
| block (intercept) | 0.0092 | SD | no. of groups | no. of observations |
Note. DAPf = days after planting (DAP) modeled as a categorical factor in the discrete-time emergence model. Evaluation days were 7, 10, 14, 21, 28, 35, 42, 49, 56, 63, 70, and 77 DAP.
Joint tests in panel A were obtained from the selected final model, BB2, a beta-binomial generalized linear mixed model with genotype, treatment, DAPf, and their two-way interactions as fixed effects. Panel B reports the random-effect variance component for block from the corresponding selected model.
Time to 50% emergence (T50) varied substantially among genotypes and seed treatments (Figure 1). Several experimental entries reached 50% emergence substantially earlier than commercial standards, indicating useful genetic variation for establishment-related traits.
Heatmap analyses further demonstrated cumulative emergence advantages relative to the commercial cultivar ‘Zenith’ (Figure 2), while cumulative emergence curves identified breeding lines with rapid and sustained emergence throughout the evaluation period (Figure 3).
Several experimental entries emerged earlier and maintained substantially higher cumulative emergence than ‘Zenith’, suggesting that useful sources of reduced dormancy and improved emergence potential exist within current breeding populations.
Germplasm exhibiting rapid emergence and superior establishment characteristics is currently being incorporated into crossing programs aimed at combining improved establishment with desirable turf quality, seed yield, harvestability, and environmental adaptation.
These efforts are expected to accelerate the development of commercially viable seeded zoysiagrass cultivars capable of expanding the use of zoysiagrass across a broad range of turfgrass applications.
Bermudagrass
The UGA bermudagrass breeding program continues a long history of cultivar development for golf courses, sports fields, and landscape applications. Recent breeding successes have demonstrated the value of developing cultivars with improved stress tolerance while maintaining excellent turf quality and broad environmental adaptation. One notable example is ‘TifTuf’, released by UGA in 2014 and widely recognized for exceptional drought tolerance.
The analysis compares trait performance among two new-generation bermudagrass cultivars, ‘Tahoma 31’ and ‘TifTuf’, and the industry-standard cultivar ‘Tifway’, all of which are commercially important hybrid cultivars. ‘Tahoma 31’ (OKC 1131), released by Oklahoma State University in 2019, is widely recognized for exceptional cold tolerance, while ‘TifTuf’ (DT-1) is widely recognized for exceptional drought tolerance. ‘Tifway’ (Tifway 419), released in 1960, was included as an industry-standard check cultivar.
Data were compiled from National Turfgrass Evaluation Program (NTEP) trials and USDA Specialty Crop Research Initiative (SCRI) projects conducted across multiple environments throughout the United States. Trial coverage, including the number of locations and measurements by trial, trait, and cultivar, is summarized in Table 2.
| Triala | Traitb | Number of Locationsc | Number of Measurementsc | ||||
|---|---|---|---|---|---|---|---|
| ‘Tahoma 31’ | ‘TifTuf’ | ‘Tifway’ | ‘Tahoma 31’ | ‘TifTuf’ | ‘Tifway’ | ||
| NTEP 2013–2017 | Spring Greenup | 18 | 18 | 18 | 45 | 45 | 45 |
| Turf Quality (TQ) | 18 | 18 | 18 | 428 | 428 | 428 | |
| TQ Under Drought | 2 | 2 | 2 | 43 | 43 | 43 | |
| Fall Color | 17 | 17 | 17 | 65 | 65 | 65 | |
| NTEP 2019–2023 | Spring Greenup | 20 | 20 | 20 | 41 | 41 | 41 |
| Turf Quality | 20 | 20 | 20 | 423 | 423 | 423 | |
| TQ Under Drought | 2 | 2 | 2 | 75 | 75 | 75 | |
| TQ Under Shade | 1 | 1 | 1 | 27 | 27 | 27 | |
| Fall Color | 16 | 16 | 16 | 48 | 48 | 48 | |
| SCRI 2010–2015 | Spring Greenup | na | 5 | 5 | na | 12 | 12 |
| Turf Quality | na | 8 | 8 | na | 95 | 95 | |
| TQ Under Drought | na | 8 | 8 | na | 61 | 61 | |
| Fall Color | na | 2 | 2 | na | 2 | 2 | |
| SCRI 2011–2012 | Spring Greenup | 1 | 1 | na | 1 | 1 | na |
| Turf Quality | 5 | 5 | na | 24 | 24 | na | |
| TQ Under Drought | 4 | 4 | na | 6 | 6 | na | |
| Fall Color | 2 | 2 | na | 2 | 2 | na | |
| SCRI 2016–2019 | Spring Greenup | na | 5 | 5 | na | 17 | 17 |
| Turf Quality | na | 5 | 5 | na | 236 | 236 | |
| TQ Under Drought | na | 5 | 5 | na | 184 | 184 | |
| Fall Color | na | 3 | 3 | na | 7 | 7 | |
| SCRI 2019–2023 | Spring Greenup | 8 | 8 | 8 | 36 | 36 | 36 |
| Turf Quality | 8 | 8 | 8 | 113 | 113 | 113 | |
| TQ Under Drought | 8 | 8 | 8 | 104 | 104 | 104 | |
| PGC Under Drought | 6 | 6 | 6 | 117 | 117 | 117 | |
| Fall Color | 7 | 7 | 7 | 23 | 23 | 23 | |
| ᵃ NTEP = National Turfgrass Evaluation Program; SCRI = Specialty Crop Research Initiative, a USDA-funded grant program. Trial years indicate the evaluation periods. ᵇ PGC Under Drought = percent green cover under drought. ᶜ Number of locations and number of measurements are reported separately for each cultivar and trait; na indicates that the cultivar was not represented in that trial comparison. | |||||||
Weighted-mean frequencies with which each cultivar was classified in the top-performing statistical group are presented in Figure 4. Using a 10-percentage-point threshold to describe practical differences, ‘TifTuf’ was comparable to ‘Tahoma 31’ for spring green-up, turf quality, and turf quality under shade.
However, ‘TifTuf’ exhibited substantial advantages for drought-related traits and fall color retention, exceeding ‘Tahoma 31’ by 41 percentage points for turf quality under drought, 58 percentage points for percent green cover under drought, and 47 percentage points for fall color.
Compared with the industry-standard cultivar ‘Tifway’, ‘TifTuf’ demonstrated higher weighted-mean frequencies for all evaluated traits, including spring green-up, turf quality, turf quality under drought, percent green cover under drought, turf quality under shade, and fall color. Overall, ‘TifTuf’ showed the clearest advantage over both comparison cultivars for drought-related traits while maintaining performance comparable to ‘Tahoma 31’ for spring green-up, overall turf quality, and shade response.
Current breeding efforts continue to build upon these successes through the evaluation of advanced experimental germplasm and commercially available standards. Newly established evaluation trials provide opportunities to identify superior selections with improved turf quality, density, color, drought tolerance, and adaptation across diverse management environments.
Complementary breeding efforts in centipedegrass focus on developing improved cultivars for low-input turf systems throughout the southeastern U.S. Emphasis is placed on improving turf quality, persistence, and adaptation while maintaining the desirable management characteristics that have made centipedegrass an important species for residential and commercial landscapes.
Cool-Season Turfgrasses
The cool-season turfgrass breeding and evaluation program focuses on developing cultivars capable of maintaining acceptable performance under the heat, drought, and disease pressures characteristic of the transition zone. Research activities include breeding progeny evaluations, advanced variety trials, and disease-screening nurseries in tall fescue, perennial ryegrass, Kentucky bluegrass, and fine fescues.
Tall fescue breeding efforts emphasize the development of cultivars with improved summer performance, persistence, turf quality, and resistance to major diseases including gray leaf spot and brown patch. Current evaluations include a breeding progeny nursery established in fall 2025, advanced variety trials containing commercial cultivars and UGA experimental germplasm established in October 2025, and gray leaf spot disease screening trials containing commercial and near-commercial entries. These trials are evaluated for establishment, turf quality, persistence, summer stress performance, disease resistance, and overall adaptation under southeastern growing conditions. Emphasis is placed on identifying germplasm with improved resistance to gray leaf spot and brown patch while maintaining the turf quality and persistence required for transition-zone environments.
Additional cool-season research includes replicated evaluations of perennial ryegrass, Kentucky bluegrass, and fine fescues established in October 2025. These trials contain commercial standards and advanced experimental germplasm and are evaluated for establishment rate, genetic color, turf quality, disease resistance, and adaptation to environmental stresses. Major diseases under evaluation include brown patch and dollar spot in perennial ryegrass; summer patch, dollar spot, and rust diseases in Kentucky bluegrass; and dollar spot in fine fescues.
Collectively, these evaluations provide critical information for identifying superior germplasm and advancing breeding populations adapted to the environmental challenges of the southeastern U.S.
High-Throughput Phenotyping and Future Directions
Advanced phenotyping technologies are increasingly integrated throughout the UGA turfgrass breeding program to improve the efficiency and precision of selection decisions. Unmanned aerial systems equipped with RGB, thermal, multispectral, and hyperspectral sensors are routinely deployed throughout the growing season to collect objective measurements of turfgrass performance across breeding nurseries and evaluation trials. These technologies provide high-resolution data for traits including establishment, turf quality, canopy temperature, drought response, heat tolerance, and disease resistance.
The integration of high-throughput phenotyping with traditional breeding approaches provides new opportunities to increase evaluation capacity, improve selection efficiency, and accelerate genetic gain. Future breeding efforts will continue to emphasize the development of climate-resilient turfgrass cultivars capable of maintaining high-quality performance under increasingly challenging environmental conditions while providing sustainable solutions for the turfgrass industry.
