International Turfgrass Society Research Journal最新文献

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).

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.

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.

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.

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.

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 (2n = 2x = 14) perennial ryegrasses (L. perenne L.), three tetraploid (2n = 4x = 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.

Bermudagrasses (Cynodon Rich. species) easily contaminate fields of zoysiagrasses (Zoysia Willd. species) through vegetative propagules and seeds, and once established, can be hard to eradicate. Zoysiagrasses and bermudagrasses vary in color, texture, and canopy architecture; infestations can be visually identified when dew is present. Field research conducted in 2024 quantified the volume of dew retained in Tifway hybrid bermudagrass (Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt Davy) and Meyer Japanese lawngrass (Zoysia japonica Steud.) canopies. The hybrid bermudagrass canopy held a greater volume of dew than Japanese lawngrass at all collection times between sunrise and 150 min after sunrise. Aerial imagery was collected from three sites comprising varying degrees of contamination of bermudagrasses in Japanese lawngrass to test the effectiveness of an artificial intelligence-based, supervised classification tool (Magic selection tool in PIX4Dfields) in delineating bermudagrasses from Japanese lawngrass. The Magic selection tool's ability to distinguish bermudagrasses from Japanese lawngrass depended on the density of the turfgrass stand, background soil color, presence of other grasses, presence of clippings, and dew volume. Based on dew volume, the ideal time to scout fields for contamination of bermudagrasses is within 90 min of sunrise and when dense stands of both grasses are present.

Clarireedia spp. are known as the fungal pathogen causing dollar spot disease in turfgrasses. We already reported Clarireedia jacksonii on cool-season grasses and Clarireedia monteithiana on warm-season grasses in Japan. But the fungal group TG1 could not belonged to any known species of Clarireedia. In results of checking the nucleotide sequences of ribosomal DNA internal transcribed spacer (rDNA-ITS), elongation factor-1α (EF1α) gene, and mini-chromosome maintenance protein (MCM7) gene, two strains, B10 and B11, belonging to the group TG1 were concluded to be a new Clarireedia species based on morphological characteristics and molecular phylogeny, and we named it Clarireedia japonici n. sp. The species was isolated from creeping bentgrass and has been found only in Shizuoka and Kyoto Prefectures, in central Japan. Since we have already reported the strain B10 showed strong pathogenicity in bentgrass, but not so strong in zoysiagrass, C. japonici was estimated to be virulent to bentgrass, the cool-season grass like C. jacksonii that was most closely related in the molecular phylogeny.