Monthly Archives: March 2013

A Closer Look at Frequency-of-Clip: Making mower adjustments

An operator checks the frequency-of-clip (FOC) setting on his mower during the 2012 Professional Golfers Association (PGA) Championship of Canada held at Country Hills Golf Club in Calgary. Photo © Scott MacArthur

By Adam C. Slick

Traditionally, the only way to change frequency-of-clip was to change reel blade count and/or alter mow speed. To help superintendents increase frequency-of-clip (FOC) quickly and easily, equipment manufacturers have recently added blades to standard reels, with some manufacturers adding 15- and 14-blade reels to their lineup.

In addition to changing blade count and mow speed, all mowers offer some level of FOC control, most using gears and pulleys.

Some manufacturers have taken FOC controls one step further. For example, on some mowers, superintendents can adjust the FOC on a liquid crystal display (LCD) screen in a matter of seconds. Since some reels are driven from individual motors separate from the tractor, the FOC remains constant, even if the speed of the mower changes.

In the end, frequency-of-clip is another equipment setting superintendents can adjust to adapt mowers to course conditions. If you have not experimented with FOC on your equipment, it is definitely worth exploring. A little adjustment here and there can make a big difference on your turf.

Read the full article: A Closer Look at Frequency-of-Clip

Controlling Turfgrass Diseases: Snow mould control

A microdochium patch on a fairway following snow melt. Photo courtesy Nancy Dykema

By Joseph M. Vargas Jr.

Years ago, controlling snow mould was easy and simply involved applying mercury fungicide in the fall. Then, mercury fungicides were banned and controlling snow mould became a little more difficult. There were still quintozine products for control, which made things a bit easier; however, this author did not like to see them used on greens because of their root-pruning properties.

Quintozine was a good fairway product and was inexpensive, but it has now been banned. Fortunately, many researchers felt this restriction was coming and began testing existing products as replacements. What they found was to get adequate snow mould control of the three dominant pathogens—Typhula incarnata, Typhula ishikariensis, and Microdochium nivale—three-way fungicide combinations were needed. Many different combinations were found to work, but the reliable tank mix is generally chlorothalonil and a DMI fungicide, which work well on the Typhula species, and then QoI or iprodione fungicide added to assist with control of Microdochium nivale.

There is a three-way product with a different combination of fungicides (i.e. propiconazole-fludioxonil-chlorothalonil). All three are necessary to control the snow mould complex. Additionally, it only requires one annual application. Resistance develops quickly when repeated applications are made throughout the season against a single fungal pathogen. We are dealing with multiple pathogens requiring different chemistries for control.

Read the full article: Controlling Turfgrass Diseases

A Closer Look at Frequency-of-Clip: Getting started

An operator mows a green at Sage Valley Golf Club in Graniteville, S.C. The course consistently ranks as one of the top-rated in North America. Photo © Dan Brice

By Adam C. Slick

Although frequency-of-clip (FOC) is a very precise formula, it is not always an exact science on the turf. Superintendents new to FOC will work with their technicians to experiment with different settings, usually moving up or down 10 to 20 per cent at a time. To monitor changes, superintendents may use a prism to evaluate stragglers and record Stimpmeter readings after FOC changes. Some superintendents actually weigh clippings to compare grass volumes at different FOCs.

After experimenting, superintendents will arrive at an ideal series of FOC settings for:
● daily play;
● post-topdressing or aerifying;
● tournaments; or
● severe weather conditions.

Some mowers allow up to six FOC presets that can be programmed into the mower’s control box.

Read the full article: A Closer Look at Frequency-of-Clip

Surviving a Municipal Cosmetic Pesticide Ban: New products

Trichoderma—the greenish fungi growing in circles on the special selective pink agar—recovered from leaves of plants treated in a 2012 field trial. Photo courtesy Deborah Henderson

By Deborah Henderson, PhD

Some new fungicide products are becoming available to help control soil-borne diseases. One registered now in turf is a bacterium (Bacillus subtilis, Rhapsody) for controlling a broad spectrum of bacterial and fungal diseases of turf including Brown Patch, Anthracnose, and Dollar Spot. A second is a fungus (Trichoderma harzianum, Rootshield) that has not yet been registered for turf, but controls soil-borne diseases in ornamentals.

A reality check for all new biological and low-risk pesticides is they do not work like chemical pesticides. This author suggests paying more attention to the label instructions; do not wait until a pest or disease is epidemic, take a proactive approach. As a pest manager, you need to know more about your system as well as these new products. Small-scale ‘trials’ with any new product are a great way to get some experience with them.

Some new low-risk herbicides seem to work well and others are more fussy about how they are used. Get to know them. Even if a product does not work for you in some situations, it may work quite well in others, so it is important not to give up until it has been tried a few times in different conditions. To get the best out of new soft products, they need the best chance for success. These are your new tools and they will perform best when used within IPM strategies where you employ all available tactics to suppress weeds, pests, and diseases.

Read the full article: Surviving a Municipal Cosmetic Pesticide Ban

Controlling Turfgrass Diseases: Crown-rot anthracnose

Crown-rot anthracnose (CRA) on a putting green. Photo courtesy Joseph M. Vargas Jr.
By Joseph M. Vargas Jr.

Crown-rot anthracnose, caused by Colletotrichum cereale, remains the most important disease of the past decade on golf course greens. This is because of the demand by golfers for ‘fast greens,’ which is accomplished by lowering the mowing height and reducing the nitrogen fertility. These two factors exacerbate CRA and have helped make it a significant disease on annual bluegrass (i.e. Poa annua) in the past decade.

Controlling CRA is also becoming a problem because of C. cereale becoming resistant to thiophanate-methyl and quinone outside inhibitor (QoI) fungicides. For years, this author has tried to convince golf course superintendents to use one class of fungicides until resistance develops, but this recommendation has mostly been drowned out by many voices urging superintendents not to forget to practice good fungicide resistance management by rotating different chemistries. This idea was supposed to work by one class of chemistry “getting rid of resistant strains that developed to a different class of chemistry,” and it might have worked if the fungus could have only become resistant to one class of chemistry at a time.

Read the full article: Controlling Turfgrass Diseases