International Turfgrass Society Research Journal最新文献

Common bermudagrass (Cynodon dactylon L. Pers.) is a widely grown warm-season turfgrass species characterized by a dense, deep-rooted canopy and high levels of traffic tolerance. However, most cultivars have poor shade tolerance, which limits the use of these grasses in partly-shaded areas. The identification of new sources of genetic resistance to shade will expand the germplasm pool available to breeders for developing improved bermudagrass cultivars. In this study, 24 common bermudagrass accessions recently introduced from South Africa were evaluated for their ability to persist under shade. Entries were established in a randomized complete block design with three replications at the Lake Wheeler Turfgrass Field Lab (Raleigh, NC) in the spring of 2019. Following full green-up in summer 2020, entries were evaluated for performance under full sun, and then a 63% shade cloth was installed over the plots. Traits evaluated under shade included: turfgrass quality, turfgrass density, genetic color, ground coverage, turfgrass regrowth and the normalized difference vegetation index (NDVI). A turfgrass performance index (TPI) was calculated to identify the top performers across all traits. Under full sun, seven accessions had comparable performance with ‘Celebration’ and ‘TifTuf’ across traits. Under shade, ‘Stil03’, ‘Q 47620’, ‘TifGrand’, ‘WIN10F’, Celebration, and TifTuf exhibited the highest TPI. Accessions with superior shade tolerance identified in this study represent novel germplasm that can be used in future breeding efforts to improve shade tolerance in bermudagrass.

There have been concerns over fertilizer nitrogen (N) applied to turfgrass areas affecting groundwater quality in sandy coastal areas since the 1970s . Extensive amount of small-scale research studies has determined the major factors that contribute to excessive nitrate-N leaching from turfgrass ecosystems. There are limited data on large-scale groundwater monitoring of turfgrass sites, such as golf courses, which are related to management inputs. There are land-use regulations limiting the amount of fertilized turfgrass in coastal area in the United States which assume a linear relationship between the amounts of N applied and leached. The purpose of this study is to evaluate the long-term impact of yearly variations in N application rate, irrigation amounts, and seasonal precipitation on groundwater quality on golf courses in critical groundwater recharge areas. Two golf courses, The Bridge and Sebonack Golf Club, in this study are in eastern Long Island, NY with systematic groundwater monitoring for NO₃–N. Each golf course follows best management practices (BMP) including limitations on amount, rate, source and timing of N applications as well as controlled irrigation based on on-site evapotranspiration measurements. The results of this study clearly show that on golf courses in sandy critical groundwater recharge areas that follow BMP, the amount of N applied is not related to NO₃–N levels in groundwater. Rainfall amounts more closely followed NO₃–N levels in groundwater, thus abnormally high rainfall can result in higher NO₃–N levels. Implementing fertilizer BMP can be very effective in protecting groundwater quality.

Golf course development has in some cases included wetland drainage or use of pre-existing wetlands. Thus, carbon dioxide loss from golf courses on organic soil can be high, whereas those on mineral soil can store carbon (C). Research indicates that mown grass can store more C than unmown grass, and that more frequent mowing, made possible with robots, can store even more. The Carbon Par project, running from 2020 up to and including 2023, estimates the C status of land used by Icelandic golf courses, to set a benchmark and thus facilitate golf's future improvement in this area. Recommendations for similar estimation elsewhere will be provided.

Bærheim Golfpark in Norway has changed most of its operations from conventional to automated mowing. The golf course has a fleet of 106 robots that mow most of the course and pick up golf balls at the driving range. The project has been innovative and today, we have the world's largest series-connected robot system. Along the way, we have encountered a number of technical and practical obstacles. Today, however, we can say that we have a facility that works well. The transition from manual to automated mowing has resulted in Bærheim becoming one of the most played golf courses in Norway. Its economy has improved significantly, the feedback from the players is very good, and the employees can use their skills on tasks other than mowing grass. We have significantly reduced the use and emissions of fossil fuels for ordinary mowers. This supports the UN's Sustainability Goal Number 13: “Climate action”.

Warm-season turfgrasses are conventionally produced and maintained as cultivar monocultures, which leaves them less resilient to pest attack than more diverse plantings. Recent evidence has indicated that mixing St. Augustinegrass [Stenotaphrum secundatum (Walter) Kuntze] cultivars can provide pest management benefits compared with cultivar monocultures. Research in other systems has shown that the effects of plant diversity on herbivores often depends on the number and identity of plant species present. Host plant diversity can affect herbivore fitness via postconsumptive physiological effects or before consumption by influencing herbivore behavior or plant defenses. To investigate the mechanisms by which St. Augustinegrass cultivar diversity and composition affect an insect herbivore, six cultivars were mixed to create two levels of cultivar diversity, and fall armyworm life history traits were tracked under no-choice diet mixing conditions and conditions where the larvae could forage among mixed cultivars. These experiments demonstrated that specific cultivar blends can reduce herbivore fitness and herbivory, and that the effects on fall armyworm fitness are likely driven by insect–plant interactions rather than postconsumptive physiological effects. The results will inform pest management strategies in warm-season turfgrass production and management, adding to the literature focused on the effects of intraspecific plant diversity.