Beyond PGR benefits

Country clubs and golf course are preparing for the sunny season, expecting a burst of growth after the early green-up this year. Cale A. Bigelow, associate professor in agronomy and turfgrass science at Purdue University, has been studying the effects PGRs have to offer in controlling that growth and the course’s budget.

“One main reason to use a PGR is to suppress the leaf growth,” Bigelow said. “Regularly applied PGRs provide smoother and more uniform playing surfaces, but there are many other beneficial effects.”

These effects also provide a smoother surface for the ball to roll with less friction and hassle, which also means a higher shot density for the player. PGR benefits also improve the coloring of the green with little water consumption, which means better control of water usage.

Beyond that, PGRs gives superintendents the ability to better manage their crew’s time spent mowing turf, freeing them up for other maintenance.

“Some places do strike mowing, which takes time, or 50/50 cut,” Bigelow said. “A lot of acres have to be mowed, and mowing it from 3 to 4 times a week can really add up. PGRs reducing fertility can be some of the considerations that people dial in when it comes to the patterns.”

Bigelow stresses that temperature matters drastically. The goal was to suppress the major cool-season turfgrass growth peaks when PGRs first came into production.

At high label rates, PGRs were applied only a few times. Bigelow says the expected duration of regulation was 4 to 6 weeks. Now, many superintendents use PGRs throughout the entire growing season with various rate strategies. The goal is to provide additional, dependable regulations.

“There is still much to learn about PGR use,” he said. “In my research program, we are focusing on understanding use patterns and improved efficacy.”

He brings up a major concern involving PGR safety. In past decades, PGRs were labeled for repeated seasonal application to fine turf, flurprimidol, paclobutrazol and trinexapac-ethyl. Each is safe to use when applied correctly as the directions indicate.

“Another suggestion when using any of these PGRs is to tank-mix a small amount of soluble nitrogen, such as urea and/or a liquid chelated iron source.”

When all is taken into consideration, Bigelow says 95 percent of golf and country clubs look at the cost. Not all states consider PGRs as pesticides. Each product has its own label for EPA safety.