Super Science: A year of research in review
Many will remember 2020 for COVID-19, protests and a contentious election.
I want to look back at all the great information provided by turfgrass scientists. Golfdom offers an excellent platform for researchers to help you. I hope you find a summary of the research takeaways helpful as we wrap up 2020.
Dollar spot susceptibility of bentgrasses
By Cole Thompson, Ph.D.
The turfgrass trials show that cultivar selection matters when considering dollar spot disease.
Figure 1 Dollar spot injury (measured as an area under the disease progress curve) for bentgrass cultivars at putting green height and without fungicide treatment. These data are a mean of responses in Kansas and Wisconsin in 2009, as well as Kansas, Iowa, Oklahoma and Illinois in 2010. Means under the same horizontal bar are not statistically different according to Tukey’s honest significant difference test (P ≤ 0.05).
- Dollar spot severity varied for bentgrass cultivars within experiments and was generally less with fungicide applications and for the putting green study.
- Overall, however, a cultivar’s relative susceptibility to dollar spot injury was similar in putting green and fairway experiments with or without fungicide applications.
- Kingpin and Memorial had the least dollar spot injury under all scenarios (putting green and fairway, with and without fungicide).
- Crystal BlueLinks, Declaration, L-93 and SR1150 were consistently similar (Figure 1).
- Crenshaw and Century had the most dollar spot injury in all scenarios and were never in the same statistical group as the best cultivars.
- Further, dollar spot injury data were consistent in each experimental location and management scenario.
- Golf course superintendents should feel comfortable using the National Turfgrass Evaluation Program or similar data to assess relative dollar spot susceptibility of bentgrass cultivars, even when close-proximity data are not immediately available.
Moving fungicides down in soil
By Wendell Hutchens, Travis Gannon, Ph.D., David Shew, Ph.D., Khaled Ahmed and Jim Kerns, Ph.D.
Photo 1 Sectioning soil into 1-inch increments to recover applied 14C-fungicide. (Photo: P. Maxwell)
Soil surfactants can help get fungicides where the pathogen attacks the turfgrass (Photo 1).
- Diseases caused by crown- and root-infecting pathogens require products and methods that effectively aid their downward movement.
- Soil surfactants applied in combinations with fungicides increase the downward movement and efficacy for crown- and root-infecting pathogens.
- The research recommends applying fungicides with a water carrier volume of 2 to 4 gallons per 1,000 square feet with irrigation of 0.125 to 0.25 inch of water immediately after fungicide application.
A new pest in the desert Southwest
By Adam Van Dyke, M.S., CPAg, and Ben McGraw, Ph.D.
Photo 2 Flea beetle (Photo: Ben McGraw)
The two researchers discuss the emerging flea beetle pest problem.
- The Southwest U.S. has an emerging insect identified as Chaetocnema minuta Melsheimer or flea beetle.
- The flea beetle (Photo 2) is relatively small — 0.08 to 0.12 inch in length — and has a dark metallic coloration.
- More research is needed to answer basic questions surrounding the pest’s biology, ecology and management in turfgrass systems.
- Turf damage primarily on perennial ryegrass originates in the golf course rough that borders native areas.
- Limited data suggest adults lay eggs in the fall, and some eggs or larvae overwinter within the turf.
- The larval activity was detected in April but peaked in July in southern Utah.
- Controlling adult populations with contact insecticides will require extreme precision in timing.
- Larvae are less likely to be affected by contact insecticides as they are protected within the plant’s stem, and preventive applications with systemic larvicides may be more appropriate.
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About the Author: Mike Kenna, Ph.D.
Mike Kenna, Ph.D., is the retired director of research, USGA Green Section. Contact him at mpkenna@gmail.com.
About the Author: Kevin Morris
Kevin Morris is the executive director of the National Turfgrass Evaluation Program. You can contact him at kmorris@ntep.com. About the Author: Cole Thompson, Ph.D.
Cole Thompson, Ph.D., is a turfgrass scientist at California Polytechnic State University, San Luis Obispo, Calif.
About the Author: Paul Koch, Ph.D
Paul Koch, Ph.D., is an assistant professor of plant pathology at the University of Wisconsin-Madison where he conducts research and provides information to professional turf managers on disease management and control. Koch's research article in the August 2013 issue of Golfdom, "Beat the summer heat, plan for snow mold," won a TOCA Award (merit) for turf feature article. Koch can be reached at plkoch@wisc.edu. About the Author: Marco Schiavon, Ph.D.
University of Florida About the Author: Ana Luiza Sousa, Ph.D.
Sousa, Ph.D.is a postdoctoral researcher in Koppenhöfer’s program. About the Author: Ryan Geisert, Ph.D.
Geisert, Ph.D., is a postdoctoral researcher in Koppenhöfer’s program. About the Author: Bruce Clarke, Ph.D.
Bruce Clarke, Ph.D. is an extension specialist in turfgrass pathology at Rutgers University. About the Author: James Murphy, Ph.D.
James Murphy, Ph.D. is an extension specialist in turfgrass management at Rutgers University. About the Author: Ben McGraw, Ph.D.
Ben McGraw, Ph.D., is an associate professor of turfgrass entomology at The Pennsylvania State University. He can be reached at bam53@psu.edu.
About the Author: Wendell Hutchens
Wendell Hutchens earned his MS degree at North Carolina State University, and now is a Ph.D. candidate at Virginia Tech University. You may reach Wendell at wendelljh@vt.edu. About the Author: Travis Gannon, Ph.D.
Travis Gannon, Ph.D., is at North Carolina State University About the Author: Dave Shew, Ph.D.
Dave Shew, Ph.D., is at North Carolina State University About the Author: Khalied Ahmed
Khalied Ahmed is at North Carolina State University
About the Author: Bruce Branham, Ph.D.
Bruce Branham, Ph.D., is a professor of turfgrass science at the University of Illinois and can be reached at bbranham@illinois.edu.
About the Author: Matt Sousek
Matt Sousek, research manager, University of Nebraska-Lincoln, can be reached at msousek2@unl.edu. About the Author: Zac Reicher, Ph.D.
Reicher is a turfgrass scientist at the University of Nebraska-Lincoln where he works with professional turf managers, teaches and conducts research. Each year Reicher conducts annual grass weed-control experiments that he uses to help formulate weed-control recommendations. Reicher can be reached at zreicher2@unl.edu for more information.
