THE RESEARCH PLAYBOOK
Winter damage affects all sorts of turf surfaces, sports fields included, but perhaps the most widespread managed turf surface is the golf green. Although golf greens don’ t cover a vast area, there are a lot of them, and greenskeepers typically have very good records of their management and performance. We also know that winterkill of golf greens is a major concern of most golf course superintendents in cold climates. Given all of this, we decided to study individual golf greens throughout the world, under the assumption that every year we should be able to find a few instances of severe winter damage and many instances where there was no damage. Both cases are important, as we need to make comparisons between those combinations of environmental factors that do cause grass to die and those that do not( we call these“ envirotypes”).
With the help of the Genetics, Environment, Management and Socioeconomics( GEMS) Informatics sensing group at the University of Minnesota, led by Dr. Bryan Runck, we were able to deploy several dozen environmental sensing nodes on greens throughout North America and northern Europe( see Figure 2).
Each fall, the GEMS team ships out nodes to collaborating golf courses, and the superintendents at these courses install the units on a green that is prone to winterkill. All winter long, every 15 minutes, those sensors record several variables— including soil and air temperatures, concentrations of oxygen and carbon dioxide, relative humidity, light, and air temperature. The data are automatically uploaded to our database via a cellular connection.
At the same time, we ask superintendents to provide information on the health and management of the green( i. e., Was it in good shape going into winter? Did it get damaged during the winter? Did you spray snow mold fungicides?). They also make weekly observations and measurements on the green( How deep is the snow? Is there any ice?).
We also can access data from satellite imagery and pull data from other public weather databases. All of the information— from humans, satellites, weather stations, and the environmental sensing nodes— gets used by computer scientists to understand how grass is or isn’ t dying during the winter. Then the rest of our team— made up of plant physiologists, plant pathologists, plant breeders and turfgrass management specialists— uses the results of those analyses to design studies that aim to offer new knowledge and recommendations about reducing turfgrass winter stress damage risk.
While the data we are analyzing come primarily from creeping bentgrass and annual bluegrass greens, the things we are learning are being readily applied to other species, such as perennial ryegrass, that are important for sports field managers. As part of this“ WinterTurf” project, we are carefully studying perennial ryegrass plants to see the types of changes they undergo during the fall as they prepare for winter. By doing so, we hope to find some physiological changes in winter-stress-tolerant perennial ryegrass plants that give the plant an advantage during the winter. Plant breeders could then select for traits associated with this change, leading to perennial ryegrass varieties that are more winter hardy. For example, researchers on our team recently discovered that differences in perennial ryegrass xylem vessel diameter may be associated with differences in low-temperature freezing tolerance.
We have much to learn, and hopefully many more winters of frigid research activity. In the meantime, we hope to communicate new ideas for getting turfgrass through winter to turfgrass practitioners of all types, with the hope that we can finally figure out winterkill. Currently, there are projects in the field at multiple university research sites investigating non-chemical snow mold control options, the use of heavy topdressing to reduce winter injury risk, and ways to improve early spring seeding success. You can stay abreast of new developments from these projects and others by visiting winterturf. umn. edu and signing up for our monthly email newsletter.
Eric Watkins, Ph. D., is a professor in the Department of Horticultural Science and vice provost for distributed learning at the University of Minnesota. His research program is focused on identifying turfgrass mixtures for Minnesota roadsides, germplasm improvement of several turfgrass species, and projects investigating approaches to reduce winter damage on cool-season turfgrasses. In his administrative role, Watkins provides leadership for online educational programs across the five-campus University of Minnesota system.
This project was supported by the National Institute of Food and Agriculture, U. S. Department of Agriculture, Specialty Crop Research Initiative under award number 2021-51181- 35861. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author( s) and should not be construed to represent any official USDA or U. S. Government determination or policy.
20 SportsField Management | May 2025 sportsfieldmanagementonline. com