Bermudagrass (Cynodon spp.) is a perennial warm-season grass that features a C4 photosynthetic pathway and is known for its drought, high-temperature, humidity, wear, and traffic tolerance (Beard 1973; Fry and Huang 2004). Ultradwarf bermudagrass [Cynodon dactylon (L.) Pers. × Cynodon transvaalensis Burtt-Davy] and hybrid bermudagrasses have been used for putting greens because of their tolerance to low mowing heights and qualities for a superior putting surface. They have fewer diseases and their performance in summer golf season is better than creeping bentgrass (Agrostis stolonifera L.) (O’Brien and Hartwiger 2014). In addition, the peak growth of the ultradwarf bermudagrass aligns with peak golf rounds in the United States (Wurth et al. 2020). Creeping bentgrass, a cool-season turfgrass, is the most commonly used turfgrass species for putting greens in the transition zone. However, managing these greens during hot and humid summers requires costly inputs while the playing conditions decline (Miller and Brotherton 2020). In response to these challenges, there has been a notable shift toward planting more bermudagrass on putting greens since the late 1990s (Hanna and Elsner 1999). This transition has resulted in substantial cost savings in terms of chemical inputs and associated labor expenses (O’Brien and Hartwiger 2014). One of the challenges to the survival and long-term success of bermudagrass on putting greens is the low winter temperatures experienced in the transition zone. Popular ultradwarf bermudagrasses lack suitable winterhardiness and are subject to severe loss by winterkill when grown in the transition zone (DeBoer et al. 2019). Addressing this issue by improving winter survivability of bermudagrass putting greens is crucial for ensuring its viability and sustainability in the long term.
Previous research conducted at Oklahoma State University (OSU) demonstrated significant variation in freeze tolerance among bermudagrass cultivars (Anderson et al. 1993, 2002, 2007; Gopinath et al. 2021a, 2021b). This variation underscores the potential for developing improved freeze-tolerant bermudagrass, which would contribute to more sustainable turfgrass management practices (Yu et al. 2022). At OSU, bermudagrass breeding efforts have been ongoing since the mid 1980s, with a primary focus on developing freeze-tolerant bermudagrass varieties (Taliaferro et al. 2004). One of the recent advancements in this area is the introduction of ‘OKC1131’ (Tahoma 31®, hereafter referred to as Tahoma 31) hybrid bermudagrass (Wu et al. 2020). It has demonstrated exceptional freeze tolerance with a lethal temperature to kill 50% of the population (LT50) at least 3.4 °C lower than ‘Champion Dwarf’ (Gopinath et al. 2021b). In addition, a recently released putting green–type bermudagrass ‘OKC3920’ exhibited similar freeze tolerance to Tahoma 31 (Gopinath et al. 2021b; Wu et al. 2022). As the breeding efforts continued, additional experimental selections of green-type bermudagrass have shown improved freeze tolerance beyond industry standards (Gopinath et al. 2021b). Considering the warm-season characteristics of bermudagrass and the low winter temperatures experienced in the transition zone, it is imperative to explore alternative approaches, including appropriate management practices, to enhance freeze tolerance alongside genotype selection.
Mowing height has long been recognized as a critical factor influencing the freeze tolerance of turfgrass (Beard 1969, 1973; Beard and Rieke 1966). A study conducted by Beard (1973) noted that reducing the mowing height in Kentucky bluegrass (Poa pratensis) from 5.0 to 3.8, 2.5, and 1.3 cm reduced cold tolerance. Similarly, Kvalbein and Aamlid (2012) observed improved spring performance on cool-season golf greens with increased mowing height in Nordic countries. This improvement is likely a result of the increased carbohydrate content during the acclimation process by raising mowing height (Qian and Fu 2005). The positive impact of increased carbohydrate levels on freeze tolerance has been reported in various other species. Shahba et al. (2003) reported an increase in carbohydrates in freeze-tolerant saltgrass [Distichlis spicata (L.) Greene] compared with its freeze-sensitive counterpart. Ball et al. (2002) discovered a greater quantity of soluble carbohydrates in freeze-tolerant buffalograss [Buchloë dactyloides (Nutt.) Engelm.] compared with a freeze-sensitive variety. Similarly, Patton et al. (2007) emphasized the importance of specific carbohydrate components, such as glucose, total reducing sugars, and total soluble sugar-to-starch ratios, in enhancing the freeze tolerance of zoysiagrass (Zoysia spp.). However, limited research exists on quantifying the impacts of mowing heights on freeze tolerance in putting green–type bermudagrass. Therefore, the objective of this study was to investigate the relative freeze tolerance of four bermudagrass genotypes and the effects of raising mowing height on the freeze tolerance of selected putting green–type bermudagrasses. By examining this relationship, this study aimed to contribute valuable insights into enhancing the winter survival and performance of bermudagrass in putting green settings.
Anderson JA, Taliaferro CM, Martin DL. 1993. Evaluating freeze tolerance of bermudagrass in a controlled environment. HortScience. 28:955–959. https://doi.org/10.21273/HORTSCI.28.9.955.
Anderson JA, Taliaferro CM, Martin DL. 2002. Freeze tolerance of bermudagrasses: Vegetatively propagated cultivars intended for fairway and putting green use, and seed-propagated cultivars. Crop Sci. 42:975–977. https://doi.org/10.2135/cropsci2002.9750.
Anderson JA, Taliaferro CM, Wu YQ. 2007. Freeze tolerance of seed- and vegetatively-propagated bermudagrasses compared with standard cultivars. Appl Turfgrass Sci. 4:1–7. https://doi.org/10.1094/ATS-2007-0508-01-RS.
Ball S, Qian YL, Stushnoff C. 2002. Soluble carbohydrates in two buffalograss cultivars with contrasting freezing tolerance. J Am Soc Hortic Sci. 127(1):45–49. https://doi.org/10.21273/JASHS.127.1.45.
Beard JB. 1969. Winter injury of turfgrasses, p 226–234. Proc 3rd Int Turfgrass Res Conf., Sports Turf Res Inst., Bingley, Yorkshire, UK.
Beard JB. 1973. Turfgrass: Science and Culture. Prentice Hall, Englewood Cliffs, NJ, USA.
Beard JB, Rieke PE. 1966. The influence of nitrogen, potassium and cutting height on the low temperature survival of turfgrasses. Agron Abstract. 1966:34.
DeBoer EJ, Richardson MD, McCalla JH, Karcher DE. 2019. Reducing ultradwarf bermudagrass putting green winter injury with covers and wetting agents. Crop Forage Turfgrass Manag. 5(1):1–9. https://doi.org/10.2134/cftm2019.03.0019.
Dunne JC, Tuong TD, Livingston DP, Reynolds WC, Milla-Lewis SR. 2019. Field and laboratory evaluation of bermudagrass germplasm for cold hardiness and freezing tolerance. Crop Sci. 59(1):392–399. https://doi.org/10.2135/cropsci2017.11.0667.
Earp R. 2023. Evaluation of experimental greens–type hybrid bermudagrass selections by genetic profiling, morphological measurements, and field testing (MS thesis), Oklahoma State University, Stillwater, OK, USA.
Fang T, Wu YQ, Moss JQ, Walker NR, Martin DL. 2017. Genetic diversity of greens-type bermudagrass genotypes as assessed with simple sequence repeat markers. Int Turfgrass Soc Res J. 13:1–8. https://doi.org/10.2134/itsrj2016.05.0435.
Fry JD, Huang B. 2004. Applied turfgrass science and physiology. Wiley, Hoboken, NJ, USA.
Gopinath L, Moss JQ, Wu YQ. 2021a. Evaluating the freeze tolerance of bermudagrass genotypes. Agrosys Geosci Environ. 4:e20170. https://doi.org/10.1002/agg2.20170.
Gopinath L, Moss JQ, Wu YQ. 2021b. Quantifying freeze tolerance of hybrid bermudagrasses adapted for golf course putting greens. HortScience. 56:478–480. https://doi.org/10.21273/HORTSCI15606-20.
Guertal EA, Evans DL. 2006. Nitrogen rate and mowing height effects on TifEagle bermudagrass establishment. Crop Sci. 46(4):1772–1778. https://doi.org/10.2135/cropsci2006.01-0006.
Harris-Shultz KR, Schwartz BM, Hanna WW, Brady JA. 2010. Development, linkage mapping and utilization of microsatellites in bermudagrass. J Am Soc Hortic Sci. 135:511–520. https://doi.org/10.21273/JASHS.135.6.511.
Kimball JA, Tuong TD, Arellano C, Livingston DP, Milla-Lewis SR. 2017. Assessing freeze-tolerance in St. Augustinegrass: Temperature response and evaluation. Euphytica. 213:110. https://doi.org/10.1007/s10681-017-1899-z.
Kvalbein A, Aamlid TS. 2012. Impact of mowing height and late autumn fertilization on winter survival and spring performance of golf greens in the Nordic countries. Acta Agric Scand. 62:122–129. https://doi.org/10.1080/09064710.2012.681059.
Lowe T. 2012. Changing times in ultradwarf bermudagrass putting green management. chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://www.usga.org/content/dam/usga/pdf/imported/course-care/lowe-changing-6-22-12.pdf. [accessed 30 Aug 2023].
Miller GL, Brotherton MA. 2020. Creeping bentgrass summer decline as influenced by climatic conditions and cultural practices. Agron J. 112(5):3500–3512. https://doi.org/10.1002/agj2.20362.
O’Brien P, Hartwiger C. 2007. Ultradwarfs in the off-season–a winter wonderland. USGA. Green Section Record. November/December. 45(6).
O’Brien P, Hartwiger C. 2013. Covering guidelines for ultradwarf bermudagrass putting greens. https://www.usga.org/course-care/2013/01/covering-guidelines-for-ultradwarf-bermudagrass-putting-greens-21474853349.html. [accessed 30 Aug 2023].
Patton AJ, Cunningham SM, Volenec JJ, Reicher ZJ. 2007. Differences in freeze tolerance of zoysiagrasses: II. Carbohydrate and proline accumulation. Crop Sci. 47(5):2170–2181. https://doi.org/10.2135/cropsci2006.12.0784.
Patton AJ, Reicher ZJ. 2007. Zoysiagrass species and genotypes differ in their winter injury and freeze tolerance. Crop Sci. 47:1619–1627. https://doi.org/10.2135/cropsci2006.11.0737.
Qian YL, Fu JM. 2005. Response of creeping bentgrass to salinity and mowing management: Carbohydrate availability and ion accumulation. HortScience. 40(7):2170–2174. https://doi.org/10.21273/HORTSCI.40.7.2170.
Shahba MA, Qian YL, Hughes HG, Koski AJ, Christensen D. 2003. Relationships of soluble carbohydrates and freeze tolerance in saltgrass. Crop Sci. 43(6):2148–2153. https://doi.org/10.2135/cropsci2003.2148.
Taliaferro CM, Martin DL, Anderson JA, Anderson MP, Guenzi AC. 2004. Broadening the horizons of turf bermudagrass. US Golf Assoc Turf Environ Res Online. 3(20):1–9.
Vincelli P, Clarke B, Munshaw G. 2017. Chemical control of turfgrass diseases 2017. Univ. Kentucky Coop. Ext. http://www2.ca.uky.edu/agcomm/pubs/ppa/ppa1/ppa1.pdf. [accessed 11 Apr 2017].
Wang Z, Wu Y, Martin DL, Gao H, Samuels T, Tan C. 2010. Identification of vegetatively propagated turf bermudagrass cultivars using simple sequence repeat markers. Crop Sci. 50:2103–2111. https://doi.org/10.2135/cropsci2010.02.0116.
Wu YQ, Martin DL, Moss JQ, Walker NR, Fontanier CH (inventors). 2020. Bermudagrass plant named ‘OKC 1131’. The Board of Regents for Oklahoma State University (assignee). US Plant Patent PP31695. (Filed 25 May 2018, granted 21 Apr 2020).
Wu YQ, Moss JQ, Martin DL, Walker NR, Fontanier CH. 2022. ‘OKC3920’ turf bermudagrass: A new cold hardy cultivar for use on golf course putting greens. Presented at the ASA, CSSA, SSSA International annual meeting, 6–9 Nov, Baltimore, MD.
Wurth AM, Ellington EH, Gehrt SD. 2020. Golf courses as potential habitat for urban coyotes. Wildl Soc Bull. 44(2):333–341. https://doi.org/10.1002/wsb.1081.
Yu S, Schoonmaker AN, Yan L, Hulse‐Kemp AM, Fontanier CH, Martin DL, Moss JQ, Wu YQ. 2022. Genetic variability and QTL mapping of winter survivability and leaf firing in African bermudagrass. Crop Sci. 62(6):2506–2522. https://doi.org/10.1002/csc2.20849.