Feature Article - February 2006
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Tough Turf

Getting athletic fields in good shape is both complicated and not-so-complicated

By Kyle Ryan

Disease and pests

Those issues vary with the type of grass used on the field; certain types are more susceptible to certain pests and disease. The three main problems Fresenberg sees are dollar spots, brown-patch disease and white grubs.

Dollar spots typically occur in Kentucky bluegrass in the spring, when daytime temperatures reach the 80s but fall back into 60s at night.

"It's usually a characteristic of those mornings where you have heavy dew, and the air just feels really damp," Fresenberg says. "Those are ideal conditions for dollar spots, and when those conditions exist and you have Kentucky bluegrass that's susceptible to dollar spots, that's when the disease will set in."

The condition also occurs, to a lesser degree, in perennial ryegrass and bent grasses, which are common on golf courses. Dollar spots also thrive on low fertility, so if a field manager maintains the field's nutrient levels, it makes the field less susceptible to the disease. Even if they still occur after that, dollar spots generally can be kept in control by fungicides.

Like dollar spots, brown-patch disease is also a fungal problem, though it tends to affect tall fescue grasses, perennial ryegrass and bentgrass, which are usually found on golf courses. The difference between brown-patch disease and dollar spots is the former favors heat and humidity, not cool, dewy mornings. In the middle of the summer, when conditions are at their hottest and most humid, patches roughly 6 inches to 2 feet in diameter can appear on the grass. But like dollar spots, brown-patch disease can be treated with fungicide.

White grubs come from insects, where the grubs feed on the root system of the turfgrass, pruning the roots and killing the grass as they eat. Fresenberg says these usually show up in late July or early August.

"It's something that you don't see every year," Fresenberg says. "Some years are worse than others, and the best way to deal with those is with insecticides."

Fields that have a history of white-grub problems can be treated with long-lasting, residual insecticides that get applied in the early summer, like around late May or early June. They typically protect the field the whole season. But if the white grubs show up out of the blue, the field still can be treated with late-season residual insecticides that also will address the issue.

Using the right fungicides, insecticides and pesticides can help keep these problems at bay, but the chemicals themselves can create their own problems because of their toxicity.

"You basically have to make sure the individuals applying these products have a pesticide-applicator's license, and they are licensed to do so," Fresenberg says. "Then just basically follow the label of the product; there's nothing outside of that specifically that you need to do. A pesticide label is actually the law approved by the EPA, so if you follow the label, you're generally following the law."

But Trigg of STMA says federal, EPA-mandated laws are being beefed up by local governments. Sometimes what the label on the product says doesn't quite go far enough.

"As an association, we are hearing more about that in different parts of the country," Trigg says. "Some of them have been very local, municipal issues that sports-turf managers have had to address or follow… Again that's networking and finding out if others have had similar situations and how they've handled it."

Of course, the trend toward "green" or eco-friendly groundskeeping offers a more natural approach to traditional chemical treatments and other practices. Again, networking can help you investigate and adopt more environmentally conscious products and treatments.