Creeping bentgrass ( Agrostis stolonifera ) and colonial bentgrass ( A. capillaris ) naturally occupy wetter and drier environments, respectively. Hybridization between these species offers valuable insights into drought tolerance and could enhance breeding strategies for developing water-deficit–tolerant bentgrasses. A greenhouse dry-down study was conducted using 52 interspecific bentgrass lines, including two parent cultivars, BCD (colonial bentgrass; drought-tolerant) and Providence (creeping bentgrass; drought-susceptible). The study revealed that the drought-tolerant hybrid plants exhibited more efficient mechanisms for drought stress management, including optimized carbon allocation, reduced oxidative stress, and enhanced water conservation. These plants were able to thrive under stress with lower levels of certain metabolites such as citric acid, malic acid, pyruvic acid, α-ketoglutaric acid, indicating a more efficient drought response compared to the susceptible group.
Chewings fescue (CF; Festuca rubra L. ssp. commutata Gaudin ‘Leeward’) seed was evaluated for use in golf course divot mixes for Kentucky bluegrass ( Poa pratensis L. ‘HGT’) tee surfaces. CF seed is typically quick to germinate and matures as a fine-textured, dark green bunch-type turfgrass. It then functions as a noncompetitive nurse grass in mature Kentucky bluegrass tee surfaces and is considered a low risk for contamination of adjacent Kentucky bluegrass rough areas. Three aspects of divot repair were investigated: (1) adding CF seed to a divot mix; (2) divot mix media; and (3) season of divot repair by creation in spring, summer, or fall. The treatments were considered acceptable only if 50% turf cover was observed within a divot recovery period of ≤56 days (8 weeks). The addition of CF seed to the divot mix was more important than the type of divot mix media used. In the fall, divot mixes without seed were unacceptable and found to have the longest divot recovery times of ≥280 days (10 months) to reach 50% turf cover, given winter dormancy halted divot recovery until spring. In contrast, fall divot mixes that contained CF seed resulted in acceptable divot recovery times of 21–28 days (3-4 weeks) to achieve 50% turf cover.
The seasonal shoot and root growth of Zoysia matrella (L.) Merr. (manilagrass) and Agrostis stolonifera L. (creeping bentgrass) were pictorially analyzed in golf course putting greens in the Kanto region of Japan. Profile samples of shoots and roots were harvested seasonally, washed free of soil, and subsequent observations of tiller, root, and thatch/mat structure were recorded. The seasonal growth cycle of creeping bentgrass was determined as (1) autumn (late September through November)—roots and shoots initiated during the previous spring and summer mature; (2) winter (December through February)—nutrients are stored; (3) early spring (March through April)—growth is more active; (4) spring (May through June)—vigorous growth occurs with initiation of new shoots; and (5) summer (July to mid-September)—parent roots and shoots senesce and are replaced by new shoots and roots. More specifically, summer growth was observed as the initiation of new shoots in June with increasing new shoot development through late July. The peak of tillering and root growth was noted as occurring from late August to early September. Most of the shoots become a single layer of new shoots from late September to early October, and autumn growth begins based on these new shoots. The seasonal growth cycle of manilagrass was determined as (1) spring (late March to late May)—parent shoots and roots senesce, and a new foundation of shoots and roots is built from those produced during the previous autumn and now in active growth; (2) summer (early June to late September)—vigorous shoot growth; (3) autumn (early October to before the first frost in December)—new shoots gradually become independent through replacement of the parent shoots; and (4) winter (first frost to mid-March)—growth is suspended and becomes dormant. An understanding of these seasonal growth cycles can be utilized by golf course superintendents in accordance with their fertilizer and thatch management programs.
Saltgrass [ Distichlis spicata var. stricta (L.) Greene], native to the western United States, is a dioecious, warm-season halophyte. CO-1 and AZCO-1 are two elite inland saltgrass lines that have potential as a turfgrass and for revegetation use on saline sites. The objectives of this study were (i) to determine the effect of sprigging date, sprigging rate, and sprig storage time on the establishment of CO-1 and AZCO-1 in the field and (ii) to determine the accumulative growing degree day (GDD) requirements for saltgrass to establish adequate coverage (≥75%). Sprigging dates were 22 May and 19 June. Saltgrass rhizomes (sprigs) were harvested from existing field plots. Harvested saltgrass sprigs were stored in sealed plastic bags and kept in temperature below 30°C for 1 or 2 days. Sprig storage time (1 or 2 days) did not affect establishment. Saltgrass sprigged in May established adequate coverage (≥75%) by the end of September at all the rates tested (18, 27, and 54 metric t ha −1 ). For plots sprigged in June, only the high and medium sprigging rates established adequate coverage (≥75%) by the end of September. Plots sprigged in June using the low rate (18 t ha −1 ) failed to establish adequate coverage by the end of September. Regression analysis predicted that a sprigging rate of 23 t ha −1 was needed to achieve ≥75% coverage by the end of September for plots sprigged in June. The accumulated GDD to achieve adequate coverage was 1531 and 1703 for 54 and 27 t ha −1 sprigging rates, respectively.
This year 2025, JSTS will celebrate its 53rd anniversary since its founding as Japanese Turfgrass Research Society. I believe it is of great significance at this point to look back on the history of the society, remember the hardships of many predecessors, and think about the future development of JSTS.
Advancements in digital three-dimensional (3D) imaging technology have enabled precise, high-throughput, and non-destructive phenotyping of plant morphology. In this study, we developed a digital phenotyping system specifically tailored for zoysiagrass ( Zoysia species), integrating image-based 3D model reconstruction, machine learning, and computational trait analysis. By employing a structure from motion approach, we reconstructed detailed 3D models of zoysiagrass using four industrial cameras and an automated imaging platform. A machine learning algorithm was applied to accurately isolate plant components from non-plant elements. From these segmented models, we extracted key morphological traits—height, spread area, color, and volume—providing a comprehensive dataset for breeding applications. As a digitally derived trait, volume offers new potential in characterizing plant architecture and assessing yield-related traits non-destructively. Additionally, we developed a small-scale, low-cost prototype system using Raspberry Pi and LEGO-based components, demonstrating the scalability and adaptability of 3D phenotyping systems across various experimental settings and budgets. Although 3D phenotyping under controlled conditions using potted plants is not directly transferable to field-based evaluation, it provides essential, reproducible data that bridge early-stage screening and later field validation in breeding programs. These digital morphological measurements are expected to enhance the precision, repeatability, and objectivity of turfgrass evaluation. As 3D technologies continue to evolve and integrate with genomic and environmental data, digital phenotyping will play an increasingly important role in accelerating turfgrass improvement and promoting data-driven plant breeding.
In Japan, the school grounds covered with turfgrasses were rare until the 1970s. Starting in the mid-1970s, the national and local governments began to support planting turfgrasses on school grounds. The planted turfgrasses in larger schoolyards remained longer, while those in smaller schoolyards in urban areas disappeared soon after planting. It has often been the case that the governments only provide budgets for the initial planting, not leaving enough for maintenance. Therefore, maintenance work became a heavy burden on teachers and school staff, leading to decades of stagnation of the development of the school turf. Then, the turfgrasses at stadiums began to draw attention due to the opening of the J League in 1993 and Japan and Korea's joint hosting of the FIFA World Cup 2002, making turfgrass planting on schoolyards more popular. Government offices and various organizations joined to support turfgrasses in several ways, making it popular for school children, parents, and residents to participate in the process of planting and taking care of turfgrasses, as well as variety of events to be held on the lawn. Turfgrasses on school grounds ended up building beautiful communities with creative activities and interactions. Before 2000, most turfgrass species were Zoysiagrasses ( Zoysia matrella and Z. japonica ), while more schools started to use Bermuda grasses (Cynodon spp.), especially Tifway, starting around 2000. Some schools have been overseeded with perennial ryegrass. Until around 2000, most school grounds in Japan were planted with square turfgrass sods, while the use of potted seedlings has now become widespread.
We have collected and analyzed genetic resources of the Zoysia genus and investigated the phylogenetic relationships using DNA markers and genome analysis. On the other hand, we also carried out interspecific hybridization to develop new varieties using the collected genetic resources and have established tissue culture techniques and genetic transformation toward developing state-of-the-art molecular breeding programs of the Zoysia genus. In this article, we will introduce the results of these efforts.
Zoysiagrasses ( Zoysia spp.) are popular warm-season turfgrass species for home lawns, landscapes, and golf courses in the southern United States due to their lower input needs. However, persistent drought conditions necessitate the development of new cultivars with reduced irrigation requirements. This research addresses this critical need through a multi-institutional, collaborative breeding project supported by USDA-NIFA Specialty Crops Research Initiative grants. The primary objective was to improve drought tolerance in zoysiagrass, bridging a gap in the availability of resilient turfgrasses. Our approach involved multi-environment testing across the southern United States coupled with advanced phenotyping techniques, including the integration of small unmanned aircraft systems (sUAS) to collect visual (red, green, blue) and multispectral imagery. A regression analysis identified significant genetic gains for turfgrass quality under drought, with a noteworthy 10.4% increment per breeding cycle. This collaboration led to the successful commercialization of several new cultivars—including Brazos™, CitraZoy®, and Lobo™—which consistently outperformed industry standards like Zeon and Palisades in turfgrass quality and drought resistance. These new cultivars exhibit improved establishment rates, disease resistance, and wider geographical adaptability. In conclusion, this research confirms that multi-institutional collaboration, combined with the strategic adoption of sUAS-based phenotyping and advanced data analysis, is a powerful and efficient strategy for turfgrass breeding. The successful development and release of these superior cultivars provides environmentally sustainable options for a wide range of applications, offering significant benefits to both producers and consumers by reducing irrigation needs.
Turfgrasses exhibit significant potential for the phytoremediation of pesticide residues. However, the understanding of their phytoremediation capabilities remains limited. This study aimed to investigate the factors influencing phytoremediation behavior, including pesticide types, concentration, exposure duration, and plant species. Three common cool‐season turfgrass species— Lolium multiflorum Lam. (annual ryegrass), Lolium perenne L. (perennial ryegrass), and Festuca arundinacea Schreb. (tall fescue)—were utilized to assess their effectiveness in removing three residual pesticides (paclobutrazol, imidacloprid, and imazethapyr) from contaminated environments. The results indicated that the phytoremediation capabilities of turfgrasses are species‐specific, with a notable preference for certain residual pesticides. Annual ryegrass exhibited a higher removal rate for residual pesticides than perennial turfgrass, which correlated with its enhanced transpiration rate. Specifically, annual ryegrass demonstrated superior efficiency in remediating residual paclobutrazol compared to imidacloprid and imazethapyr. Correlation analysis further identified the translocation factor as a critical determinant of difference in removal rate. These findings offer valuable insights for optimizing the application of turfgrasses in the remediation of pesticide‐contaminated environments.
Experience from using loss on ignition with verdure intact on more than 1000 greens in Scandinavia tells us there is no magic number for the percentage of organic material in golf greens. Only with a clear purpose, a sampling compliant with the purpose, observations during sample preparations, and a team effort for evaluating the results can you make decisions on how and what to improve maintenance methods to gain business benefits from better playing quality.
Evidence is provided for the proposition that soil analysis should be interpreted for dominance of Agrostis capillaris over Poa annua in putting greens. Using a database of soil analysis results and golf green species composition, 64 combinations of test results were devised. Each was evaluated for statistical difference between A. capillaris and P. annua for three increments of cation exchange capacity (CEC) and pH. Boxplot increments with pH were assessed for separation between A. capillaris means and P. annua interquartile zones. Inconsistent results were eliminated. The test results most suitable for interpretation were K + Mg 10.8 (%BS), Mg 5.7 (%BS), K 3.4 (%BS). The target zone for A. capillaris dominance is the area below P. annua quartile 1 representing 81.5%–92.5% of A. capillaris , alternatively pOH/K+Mg 0.8 (%BS), pOH/K 2.6 (%BS), and CEC 8 (meq/100 g) could be used with 78.1%–91.8% of A. capillaris above P. annua quartile 1. CEC could be used with either option but is only valid <20 (meq/100 g).
Silvery thread moss ( Bryum argenteum Hedw.) (STM) is a common weed on golf course putting greens. Limited herbicidal options are available for the control of STM. Previous research suggests that certain contact fungicides may have efficacy against STM; therefore, a study was conducted to explore fungicidal options for managing STM on golf course putting greens. The study was conducted in Fayetteville, AR, on a “Pure Eclipse” and “Ninety‐Six Two” creeping bentgrass ( Agrostis stolonifera L.) green. Every combination of the fungicides chlorothalonil, fluazinam, mancozeb, and thiram was tested, along with carfentrazone‐ethyl, an industry‐standard herbicide, and a nontreated control for a total of 17 treatments. Treatments including chlorothalonil were the most effective at reducing STM coverage, while the combination of fluazinam + mancozeb + thiram was moderately effective at controlling STM. In a supplemental study conducted in Blacksburg, VA, chlorothalonil greatly reduced moss coverage, while potassium phosphite and fosetyl‐Al were ineffective. These results give turfgrass managers an alternative to carfentrazone‐ethyl for managing silvery thread moss on their putting greens.
DLF France started looking at carbon sequestration on its trial grounds at Les Alleuds, near Angers, France, in 2008, based on trial plots sown in 2005. It all started as a joke “Why can we get carbon credits for planting trees but not for sowing grass?”. A brief internet search revealed that although trees store more carbon overall (tree trunks, branches, and roots), the carbon sequestration of grassland (soil and roots overall) exceeds that of trees. Our first results were presented to the European Turfgrass Society in Norway in 2012. Now, 15 years since our first investigations started, we have continued our research to cover France and Denmark and 55 grass cultivars in eight species.
Research was conducted to investigate the effect of mowing frequency on the turf quality of Zoysia matrella fairway using a unmanned autonomous mower (ULM271, Kyoeisha Co., Ltd.) at a golf course in the Kanto region, Japan. Two mowing programs were developed, with Program 1 mowing the entire fairway and program 2 mowing the same fairway but skipping mowing at small research plots on the fairway. The operator chooses two programs alternately to make the mowing frequency at the research plot almost half of remaining fairway. The turf quality, shoot density, and turfgrass dry weight were measured every month during the growing season. Though there are no significant differences in turfgrass growth and quality observed, the research will be continued with increased mowing frequency.
White grub is one of the most problematic turfgrass pests in Japan. Because the damage caused by these grubs is difficult to detect at the ground level, a simple method for assessing damage from above the ground is required. Recent studies have developed techniques to evaluate pest‐induced damage to various crops using the normalized difference vegetation index (NDVI), and reports have suggested that grub‐induced damage to turfgrass can be detected. This study aimed to investigate whether NDVI, obtained via an unmanned aerial vehicle (UAV)‐based method, could be used to visualize grub‐induced damage to turfgrass. The experiment was conducted on Zoysia matrella (L.) Merr. where Anomala schönfeldti Ohaus occurs naturally. Three insecticides were applied in June 2023; grubs were counted in September; and NDVI was measured in July, September, and October. The results indicated that grub populations decreased in some insecticide‐treated plots; however, no significant differences in the NDVI were observed. Further research is required to assess grub damage using UAVs, particularly to identify field conditions and refine parameters specific to grub‐induced damage.
Cross country is one of the three equestrian disciplines, including eventing, and it has a high injury and fall risk for the horse and rider. Testing cross‐country ground in terms of soil compaction and penetration gives valuable information regarding the ground condition for competition. The objective of this study was to evaluate the quality of a Chilean cross‐country ground for equestrian eventing after the Santiago 2023 Pan‐American Games using field parameters and complementary soil analysis. Turf on the cross‐country area mainly comprised kikuyugrass ( Cenchrus clandestinus (Hochst. ex Chiov.) Morrone), a natural turfgrass species found at the location. The total route distance of the cross‐country was 3700 m, and data were taken at each 250 m of the route completing a total of 27 points, considering at least two replications on obstacle points. One data point was not considered in the analysis. Parameters measured were soil temperature, volumetric water content, soil salinity (dS/cm) measured as electrical conductivity using a TDR 350; soil compaction using 2.25 kg Clegg impact hammer (CIH); soil penetration using a Longchamp penetrometer (LP); turfgrass height, thatch depth and turfgrass vigor using FieldScout TCM 500 NDVI turf color meter. Data sets were taken in January (summer) and July (winter) during 2024. Differences between seasons were detected for CIH and Delta LP values. Despite seasonal variations, volumetric water content (VWC) and soil texture significantly influenced surface condition, with this study showing that this was true especially the case where obstacles were at high elevation and had low turfgrass density. Agronomic management strategies that account for environmental variations, such as implementing a consistent irrigation program, aeration, topdressing, and maintaining sufficient turfgrass cover, should be carefully addressed prior to any event. Future research considering evaluations in different seasons and points are needed to improve safety for horses and riders in Chile.
Bermudagrass is often overseeded with cool‐season turfgrass in the winter to provide an actively growing green surface during the winter and early spring. Perennial ryegrass ( Lolium perenne L.) is the most widely used cool‐season turfgrass for overseeding situations, but it can become a problematic weed following overseeding because of improved heat and drought tolerances. Therefore, other turfgrass species need to be evaluated to find alternatives that can provide a quality surface while also transitioning out after the overseeding season. The aim of this study is to investigate alternative cool‐season turfgrass species for overseeding dormant bermudagrass. Five annual ryegrass ( L. multiflorum Lam), two diploid (2 n = 2 x = 14) perennial ryegrasses ( L. perenne L.), three tetraploid (2 n = 4 x = 28) perennial ryegrasses, one meadow fescue ( Festuca pratensis Huds.), and two American ryegrass cultivars [× Festulolium loliaceum (Huds.)] were evaluated in this study. Visual ratings were taken monthly to assess performance traits such as turfgrass quality, color, density, and texture. Transition ratings were taken in May and December to evaluate the emergence of the bermudagrass in the spring and the survival of the cool‐season grasses through the summer. The perennial ryegrass cultivars had the highest average turfgrass quality ratings throughout the study. Two annual ryegrass cultivars also had high average turfgrass quality and were not statistically different from perennial ryegrass cultivars. The turf‐type annual ryegrass cultivars also transitioned out completely without herbicides, whereas significant survival of the diploid perennial ryegrasses was observed. Tetraploid ryegrass cultivars displayed a dark color throughout the overseeding season, but they did not transition any more than diploid perennial ryegrass. Newer, improved annual ryegrass cultivars appear to be a viable option for overseeding situations that want to avoid using cultural or chemical controls to induce the transition of cool‐season overseeding grasses in late spring.
Disease incidence trend of creeping bentgrass ( Agrostis stolonifera L.) in Japan was investigated based on diagnosis results during 2013–2022. Anthracnose was identified most frequently, followed by bacterial disease, and then Pythium disease. The number of samples diagnosed as these diseases increased in summer. In addition, basidiomycete diseases and pink snow mold were identified frequently. As dollar spot is easily identified on site, the number of the sample was low. In recent years, due to consistently high temperatures, the number of samples in September has tended to increase. Among bacterial diseases, brown stripe (bacterial decline) was identified most frequently, followed by halo blight and bacterial leaf blight. The incidence of brown stripe has tended to increase.
