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Golf facilities account for 2.3 million acres in the United States. Numerous turfgrass species are managed on US golf facilities, but golf facilities may change turfgrasses depending on numerous variables. Knowing which turfgrasses are grown and how turfgrass selection has changed would provide important information to scientists, turfgrass managers, and policymakers. The objective of this survey was to measure turfgrass use on US golf facilities in 2021 and to determine whether changes in turfgrass selection have occurred since 2005. A survey was developed and distributed via e-mail to 13,938 US golf facilities, with 1861 responding. From 2005 to 2021, the total projected area of maintained turfgrass on US golf facilities decreased by 14.2%, which was likely a result of course closures and maintenance operations. Nationally, bermudagrass (Cynodon sp.) and Kentucky bluegrass (Poa pratensis) remained the most common warm- and cool-season turfgrasses, respectively. The area of winteroverseeded turfgrass declined by 60% between 2005 and 2021. The percentage of golf facilities that used zoysiagrass (Zoysia sp.) and seashore paspalum (Paspalum vaginatum) increased depending on region and specific playing surface, albeit a pragmatically minor increase. In general, turfgrass selection on golf facilities in northern climates did not change, whereas turfgrass selection in southern climates favored a change from cool- to warm-season species, depending on the playing surface. Whether in historically cool-season or warm-season regions, it appears that many golf facilities are exploring alternatives to their traditional turfgrass species. [ABSTRACT FROM AUTHOR]

Consumers often have multiple choices when purchasing retail lawn products in stores. In this study, we evaluated the acute drought performance of locally available retail lawn seed products (mixtures or blends) at two mowing heights of 2.5 and 3 inches. We hypothesized that the species present in the products and the height-of-cut differentially influence the drought resistance and recovery of the mixtures and blends. In Fall 2016 and 2017, 28 different products consisting of 25 mixtures and 3 blends of turfgrass seeds were established under a fully automated rainout shelter at the St. Paul campus of the University of Minnesota. The drought treatments lasted for 67 days in 2017, and 52 days in 2018; both the 2017 and 2018 treatments were followed by a recovery period. Data were obtained during acute drought treatments and recovery periods for visual turfgrass quality and green turfgrass cover using digital images of the plots. During the first year, several products displayed higher green stability (or the ability to remain green) at the 3-inch height-of-cut compared with the 2.5-inch height-of-cut. Products with tall fescue (Schedonorus arundinaceus) and fine fescue (Festuca sp.) as dominant species generally performed better during the drought treatments, whereas an increasing presence of perennial ryegrass (Lolium perenne) and kentucky bluegrass (Poa pratensis) decreased the visual drought performance of the products. During the recovery period, an effect of the interaction between mowing height and the date of data collection on the percentage of green cover was observed: the lower mowing height improved the early recovery of green cover after acute drought. These findings suggest that consumers in the upper midwestern United States and areas with a climate similar climate to that of St. Paul, MN, who are challenged with multiple choices of lawn seed products should choose products containing a higher tall fescue content and adjust their mowing heights to optimize recovery. [ABSTRACT FROM AUTHOR]

In the transition zone, warm-season grasses are often overseeded with diploid perennial ryegrass (Lolium perenne L., 2n = 2x = 14) to provide a temporary green surface for winter sporting activities. Because improved cultivars of perennial ryegrass will often persist into summer in overseeded turf, alternative cool-season grasses have been developed to facilitate more rapid transition back to the warm-season species. Limited information is available on these alternative species, especially with regard to their germination characteristics under shade and performance under limiting factors, such as low temperature and restricted photoperiod. Greenhouse and growth chamber studies were designed to test four alternative overseeding grasses in comparison with diploid perennial ryegrass, to verify their potential use in the artificial environment of modern stadiums. Meadow fescue (Festuca pratensis Huds.), tetraploid perennial ryegrass (Lolium perenne L., 2n = 4x = 28), annual ryegrass (Lolium multiflorum Lam.), and spreading diploid perennial ryegrass [Lolium perenne L. subsp. stoloniferum (C. Lawson) Wipff.] were tested. Six different shade treatments were used in the greenhouse study, including 30%, 50%, 70%, 90%, and 100% shade and a nonshaded control (0% shade). Germination was monitored daily over a 21-day period by counting and removing emerged seedlings. The experimental design for this study was a randomized complete block design, with four replications of each species and shade level for a total of 120 experimental units. In the growth chamber study, the same plant material was tested simulating optimal, suboptimal, and critical environmental conditions that can be potentially found within a modern sport facility. In the greenhouse study, the highest final germination was observed with annual ryegrass at 90% shade (98.7%), whereas the lowest for tetraploid perennial ryegrass at 30% shade (58.8%). Annual ryegrass was the fastest emerging species, whereas meadow fescue the slowest. In the growth chamber study, in comparison with perennial ryegrass, the following results may be summarized: 1) meadow fescue and tetraploid ryegrass showed coarser leaf texture, similar growth rates and Normalized Difference Vegetation Index (NDVI) value; 2) annual ryegrass had similar leaf texture, accelerated growth characteristics, and lower NDVI value; and 3) spreading perennial ryegrass displayed finer leaf texture, lower vertical growth, and similar NDVI value. [ABSTRACT FROM AUTHOR]

With the emergence of glyphosate-tolerant cultivars, identifying management strategies not applicable with older cultivars need to be revisited. Objectives of these research trials were to quantify' the growth regulation effects following a glyphosate application and to determine the safety of tank mixing glyphosate with another herbicide, various nitrogen (N) sources, and a plant growth regulator (PGR) on a glyphosate-tolerant perennial ryegrass [PRG (Lolium perenne L.)] cultivar, Replay. In the growth regulation trial, glyphosate was applied at 0 to 1.03 lb/acre, whereas PGRs flurpimidol, trinexapac-ethyl, paclobutrazol, and trinexapac-ethyl + flurpimidol were applied at 0.50, 0.18, 0.37, and 0.09 + 0.22 lb/acre, respectively, on 15 July 2010 and 2 Aug. 2012. In the tank mixing trial, dicamba (0.50 lb/acre), urea (15 lb/acre N), and ammonium sulfate [AMS (15 lb/acre N)] were applied alone or tank mixed with glyphosate at 0 to 0.52 lb/acre. Tank mixing urea with glyphosate had minimal effect on PRG color, while adding AMS consistently improved color at the highest glyphosate rate of 0.52 lb/acre. Twenty days following a glyphosate application, only rates >0.40 lb/acre resulted in significant growth regulation compared with untreated plots. This study indicates that tank mixing glyphosate with another herbicide, a PGR, and various N sources appear safe to the glyphosate-tolerant PRG cultivar. Also, the growth regulating effects of glyphosate applications would serve as an additional benefit to annual bluegrass (Poa annua L.) control reported in previous trials. [ABSTRACT FROM AUTHOR]

Indaziflam is an alkylazine herbicide that controls winter and summer annual weeds in bermudagrass (Cynodon sp.) turf by inhibiting cellulose biosynthesis. Research was conducted in Tennessee and Texas during 2010 and 2011 to evaluate the effects of indaziflam applications on overseeded perennial ryegrass (Lolium perenne) establishment and summer annual weed control. In Texas, perennial ryegrass cover on plots treated with indaziflam at 0.75 and 1.0 oz/acre measured 37% to 48% compared with 88% for the untreated control 257 days after initial treatment (DAIT). Perennial ryegrass cover following applications of indaziflam at 0.5 oz/acre measured 84% 257 DAIT and did not differ from the untreated control on any evaluation date. Inconsistent responses in crabgrass (Digitaria sp.) control with indaziflam at 0.5 oz/acre were observed in Tennessee and Texas. However, control was similar to the 0.75-oz/acre rate and prodiamine at 7.8 oz/acre at each location. A September application of indaziflam at 0.75 oz/acre followed by a sequential treatment at 0.5 oz/acre in March of the following year provided >90% control by June 2011. Indaziflam application regimes of this nature would allow for successful fall overseeding of perennial ryegrass every two years and control winter annual weed species such as annual bluegrass (Poa annua). [ABSTRACT FROM AUTHOR]

Salinity stress may involve the accumulation of glycine betaine (GB). The objective of this study was to examine whether exogenous GB would ameliorate the detrimental effect of salinity stress on perennial ryegrass (Lolium perenne). The grass was subjected to two salinity levels (0 and 250 mm NaCl) and three GB levels (0, 20, and 50 mm). Salinity resulted in a remarkable decrease in vertical shoot growth rate (VSGR), shoot and root fresh weight, relative water content (RWC), relative transpiration rate (Tr), and chlorophyll (Chl) content, superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) activities. Plants subjected to salt exhibited an increase in leaf electrolyte leakage (EL), lipid peroxidation (MDA), and proline content. Application of GB reduced EL, MDA, and proline content in salt-stressed plants. Perennial ryegrass subjected to salt stress plus GB had a greater level of VSGR, RWC, relative Tr, Chl content, and activities of SOD, CAT, and APX when compared with salt-stressed without GB. Salt stress increased Na+ and decreased K+ content, which resulted in a higher Na+/K+ ratio in perennial ryegrass. Application of 20 mm GB suppressed Na+ accumulation, whereas the K+ content was significantly increased in shoot, which led to a higher K+/Na+ ratio under saline conditions. These results suggested that GB-enhanced salt tolerance in perennial ryegrass was mainly related to the elevated SOD, CAT, and APX activity and alleviation of cell membrane damage by reducing oxidation of membrane lipid and improving the ion homeostasis under salt stress. [ABSTRACT FROM AUTHOR]

Common bermudagrass (Cynodon dactylon) and hybrid bermudagrass (Cynodon dactylon var. dactylon x C. transvaalensis) often are used for athletic fields as a result of their wear tolerance and recuperative ability. A wear tolerance study was conducted May 2007 through Nov. 2008 in Lexington, KY. Plots were managed as athletic turf and simulated traffic was applied during the Kentucky high school football seasons. The cultivars Quickstand, Tifway 419, Riviera, and Yukon grown in a sand-based medium were evaluated. Trinexapac-ethyl (TE) was applied at label rates and frequencies or left untreated. Overseeding treatments were perennial ryegrass (Lolium perenne) at 0, 546, and 1093 lb/acre pure live seed. Traffic treatments were applied with a Brinkman traffic simulator three times per week, once each Monday, Wednesday, and Friday, without regard to soil moisture status or weather for the periods 10 Sept. to 2 Nov. 2007 and 12 Sept. to 14 Nov. 2008. In both years of the study, the main effect of cultivar was significant (P < 0.05) in traffic tolerance ('Tifway 419' = 'Riviera' > 'Quickstand' = 'Yukon'). Overseeding at the medium and high rates also provided significantly greater turf cover for the coarse-textured, more open cultivars (Quickstand and Yukon) over the fine-textured, more dense cultivars (Riviera and Tifway 419). Applications of TE did not significantly improve tolerance to simulated athletic traffic in either year of the study regardless of cultivar or overseeding treatment. Within the parameters of this study, data indicate that only cultivar has significant effects on tolerance to simulated traffic on a sand-based field. Overseeding treatments for the fine-textured, more dense cultivars and TE applications on sand-based field systems had no positive significant effects on tolerance to simulated traffic [ABSTRACT FROM AUTHOR]

Turfgrass managers in the transition zone are interested in converting swards of cool-season grasses to cold-hardy seeded bermudagrass (Cynodon dactylon) in an effort to reduce water and fungicide inputs. The objective of this study was to evaluate the potential for establishing 'Riviera' bermudagrass in a perennial ryegrass (Lolium perenne) sward by using a strip-seeding technique, and then to build a machine that would facilitate the process. Four, 2-inch-wide tilled rows, 1 inch deep and 15 inches apart, were created in 6 x 6-ft plots and seeded by hand with 'Riviera' bermudagrass at 104 lb/acre pure live seed in July 2002. In one set of strip-seeded plots, a 7-cm-wide overspray of glyphosate (≈0.5 inch on either side of the row) was applied over tilled rows after seeding to suppress perennial ryegrass further. Plots established by the strip-seeding technique exhibited 71% bermudagrass coverage after two growing seasons, and 87% coverage when rows received a glyphosate overspray. Broadcasting 'Riviera' seed into perennial ryegrass plots resulted in 60% bermudagrass coverage at the end of the second season of establishment. A strip seeder was constructed and used to seed 'Riviera' into existing perennial ryegrass turf in late July 2004 using the aforementioned row configurations and a glyphosate overspray. Coverage evaluated the following spring, before green-up, was 10.3% compared with 0% coverage where 'Riviera' was broadcast seeded. At the seeding rates evaluated, 79% less 'Riviera' bermudagrass seed was required when using the strip-seeding method, and golfers would consider the surface more amenable to play during the establishment period compared with broadcasting glyphosate and seed. A patent is pending on the strip-seeding equipment and establishment process. [ABSTRACT FROM AUTHOR]

The objective of this study was to determine physiological traits for drought survival and post-drought recovery upon re-watering in two C3 perennial grass species, kentucky bluegrass [KBG (Poa pratensis)] and perennial ryegrass [PRG (Lolium perenne)]. Plants were maintained well watered or exposed to drought stress by withholding irrigation and were then re-watered in a growth chamber. KBG had significantly higher grass quality and leaf photochemical efficiency, and lower electrolyte leakage than PRG during 20 days of drought. After 7 days of re-watering, drought-damaged leaves were rehydrated to the control level in KBG, but could not fully recover in PRG. KBG produced a greater number of new roots, while PRG had more rapid elongation of new roots after 16 days of re-watering. Superior drought tolerance in KBG was associated with osmotic adjustment, higher cell wall elasticity, and lower relative water content at zero turgor. Osmotic adjustment, cell wall elasticity, and cell membrane stability could play important roles in leaf desiccation tolerance and drought survival in perennial grass species. In addition, post-drought recovery of leaf hydration level and physiological activity could be associated with the accumulation of carbohydrates in leaves and rhizomes during drought stress and new root production after re-watering. [ABSTRACT FROM AUTHOR]