TURF SCIENCE


Give PGRs Another Look

Here's how plant growth regulators can save you labor hours and other costs
By Ron Hall


Beth Stevenson
Beth Stevenson
Few chemical tools offer the potential savings that PGRs can provide to your companies. Depending upon how effectively you use them they can save you labor hours, fuel and equipment costs. Even so these chemical work savers remain below the radar of many companies.

PGRs are plant growth regulators, organic compounds (natural or synthetic) that are used in small amounts to change plant growth. They've been available to use in turfgrass for about 50 years, but it wasn't until the mid- to late-1980s that turfgrass managers, mostly golf course superintendents, began to use them regularly.

Since then, work has continued on PGRs with both university research and empirical evidence validating their effectiveness in improving turf color, increasing density, suppressing seedhead development and improving turf's recuperative potential. Encouragingly, similar strides have been made (and continue to be made) in the development of PGRs that affect the growth of ornamentals and trees.

Because of these advances an increasing number of landscape and lawn service companies are incorporating PGRs into their programs to reduce labor costs in mowing, trimming, cleanup and debris removal.

One and done

Beth Stevenson with KAB Grounds Maintenance, Poquoson, Va., is an experienced PGR user and applicator. She has worked in the green industry for more than 20 years. Each season company technicians spend 120 hours trimming the trees and shrubs on the property of an apartment complex located adjacent to the James River. The property is peppered with mature plants: hollies (several different varieties), Russian olives, ligustrum and other woody plants. Some are 30 feet tall. As each section is trimmed Stevenson follows behind and sprays it with Atrimmec, a PGR offered by PBI Gordon. This PGR works by blocking the plant hormones that stimulate growth. It's absorbed by the leaves and translocated to the shoot tips where it temporarily stops shoot elongation.

<sup>1</sup> Low-maintenance turfgrass sites: roadsides, airports, storage sites, hard-to-mow areas, etc.
Medium-maintenance turfgrass sites: industrial grounds, parks, cemeteries, golf course roughs, home
lawns.<br />
High-maintenance turfgrass sites: putting greens, tees, fairways, athletic fields, high-quality home lawns
and commercial properties.

1 Low-maintenance turfgrass sites: roadsides, airports, storage sites, hard-to-mow areas, etc. Medium-maintenance turfgrass sites: industrial grounds, parks, cemeteries, golf course roughs, home lawns.
High-maintenance turfgrass sites: putting greens, tees, fairways, athletic fields, high-quality home lawns and commercial properties.

Working from a Ford F250 equipped with a 300-gallon tank, it's not the easiest job in the world as she and a co-worker must deal with 300 feet of high-pressure hose. The spray work often requires the use of a ladder. Because the property is near a river, wind can become an issue as well, she says. Even so, spraying the trees and shrubs with the PGR is a lot less labor-intensive than pruning it. Usually, it takes three to four weeks to prune and spray the entire property.

7 Tips for Effective PGR Applications

1. Make sure the turf or plants that you are treating are healthy and growing, or on the cusp of growing. Never use a PGR on turf or other plants that are stressed or dormant and not growing.

2. Remove clippings, limbs and other debris from a turf area before you apply your PGR. Otherwise some areas of the property are not going to get the same amount of product and will not respond the rest of the lawn.

3. Because a PGR will slow turf growth, don't use it on grass that is subject to a lot of foot traffic or other stresses. That turf has to grow to recuperate, after all.

4. Give the job to a steady and experienced applicator to ensure an even application of material. That's vital to getting the results that you're seeking. If you're spraying a liquid PGR be aware that the wind can affect the effectiveness of the application.

5. Try to time your application at least eight hours before irrigation or when the next rain is expected.

6. Give the turfgrass time to absorb the product. Wait two to three days before mowing.

7. You can make your PGR application either with or after you make your preemergent applications. Why make an extra trip to a property to do it before you put down a preemergent?

And of course always read and carefully follow label directions.

"When I do a very good job, the Atrimmec does a very good job," says Stevenson, who has been using the product for more than 10 years. By "very good job," Stevenson means that the property will retain a manicured look the remainder of the season with perhaps a touchup here or there. This frees KAB Grounds Maintenance employees to perform other services. Besides eliminating the need for a second pruning each season, the use of the PGR reduces landscape waste and removal, another significant time saver.

In addition to the savings, PGRs applied to ornamentals at the proper time and rate almost always improve the quality of the plant material. It results in greener, fuller plants with more bud tips and interior branches.

In implementing its program, the Virginia company identified a specific use for the PGR. Then it calculated the PGR, equipment and application expenses and carefully weighed those costs against the labor and the time saved by not having to do a second pruning each season. That the company has been following the same program these past four years is proof that the program is working, says Stevenson.

<sup>1</sup>Paclobutrazol is also available on dry fertilizer carriers.

1Paclobutrazol is also available on dry fertilizer carriers.
CHARTS COURTESY OF THE UNIVERSITY OF GEORGIA, TIM RM MURPHY, UGA, TED WHITWELL AND L. B. MCCARTY,
CLEMSON, AND FRED YELVERTON, NORTH CAROLINA STATE.

Do the numbers

That's where you have to start when considering using PGRs. Determine what you want to accomplish and if a PGR is the best and most cost-efficient solution for getting it done.

For example, is a PGR the answer to slowing the growth of turfgrass and reducing the frequency of cuts on that hillside or along a roadway that has the potential to be a hazard to an operator? How about that large lawn area where nobody goes behind the suburban strip mall property under your care? Will an application of a PGR eliminate enough cuts over the course of a summer to more than pay for the product and its application?

Plant growth regulator suppliers such as PBI Gordon and SePRO offer online tools to help you figure the dollars and cents implications of using PGRs. The calculators on their websites can give you realistic numbers when calculating cost savings for particular uses, be it trimming, turfgrass edging or mowing. It's a good place to start.

Even after determining that using a PRG would offer significant savings, you (in fact, no prudent company owner) is going to put out good money and risk damaging customers' turfgrass or ornamentals without researching the products, discussing their use with knowledgeable suppliers and testing the products first.

Ron Hall is editor-in-chief of Turf magazine and has been an editor, researcher and writer in the green industry for more than 28 years. Contact him at rhall@mooserivermedia.com.