Verdure Live! at #GIS18

Dr. Beth Guertal’s Verdure column was brought to life by four scientists who delivered distilled summaries of their research.


Verdure Live
Some of the top publishing turfgrass scientists presented condensed versions of multi-year research projects during Monday’s Verdure Live! session, offering trickle-down science attendees can put to work on their courses. Photo by Roger Billings

Each month, readers of GCM turn to Dr. Beth Guertal’s Verdure column to read her pithy summary of research from the past. On Monday at the Golf Industry Show, three turfgrass professors and the director of Turfgrass Producers International provided equally pithy discussions of research that superintendents would find useful.

Do you ever think about the water in your spray tank? Is it just water, or could it affect the efficacy of the products you spray? Aaron Patton, Ph.D., from Purdue University found that both the pH and the hardness of the water can make a difference. In short, the effectiveness of sulfonylurea herbicides may be reduced by acidic water (alkaline water does not appear to cause problems). Iron may also be antagonistic to some herbicides and plant growth regulators. Research is still in progress, and additional results will be published in a future issue of GCM.

Clemson University’s Bruce Martin, Ph.D., a well-known turf pathologist, carried out early research on what is now called Indemnify, a fungicide that is also a nematicide. Scientists had been looking for an effective nematicide for years when Martin and others found that the active ingredient in Indemnify produced excellent results in nematode control. As Martin said, “It was pretty darn good!”

A combination of factors, including economic and climatic changes, has led superintendents to stop overseeding and start coloring — their grass, that is. Casey Reynolds, Ph.D., executive director of Turfgrass Producers International, said that paint used on athletic turf is notorious for killing the grass it covers. Athletic turf paint is meant to block out the light and cover up the green color of the grass so the colors of a football team, for example, can be proudly displayed on the field. Turf colorants, however, are designed to enhance turf color and not coat the plant leaves — coating the leaves blocks light and prevents or limits photosynthesis. In fact, turf colorants on bermudagrass, for example, are much safer for the bermuda than overseeded ryegrass, which severely limits light by shading the bermudagrass. Reynolds’ research is partly funded by GCSAA.

The final mini-lecture was delivered by James Brosnan, Ph.D., associate professor of plant sciences at the University of Tennessee, who is trying to give superintendents some tools to identify a common problem. Herbicide resistance — even multiple resistance and non-target-site resistance — is becoming increasingly prevalent, but diagnosing resistance using traditional techniques is a lengthy process. With funding from the USGA, Brosnan is developing methods that superintendents can use to rapidly determine whether the Poa annua on their courses is resistant or susceptible to a particular herbicide. Future work will expand to include multiple herbicides and additional weeds.

Teresa Carson is GCM’s science editor.