Turf & Rec

Features Agronomy
Putting IPM into action on sports fields


October 19, 2010
By Mike Jiggens


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The most important tool in a sports turf manager’s toolbox is the
manager himself and not the pesticides he’s no longer legally able to
use, attendees at the 23rd annual field day of the Sports Turf
Association were told in September.

Dr. Katerina Jordan, assistant professor of turfgrass science at the University of Guelph, told her audience at Cambridge, Ont.’s Optimist Park that Ontario’s two-year-old cosmetic pesticide ban, which prohibits conventional pesticide use on athletic fields, has made it that much more important for sports turf managers to better educate themselves about weeds and pest insects so that they can stay on top of proper identification and alternative control methods. thumb_jordanweb

“You have to adapt if you don’t have the tool you need,” she said. “You have to accept that this is what the ministry (of the environment) has decided, and we move on.”

Perhaps the most ideal way a sports turf manager can best maintain athletic fields in the wake of Ontario’s cosmetic pesticide ban is to gain a better understanding of the pest and its biology to enable sound control, Jordan said.

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Prior to the ban, pesticides had essentially taken the place of knowledge of the pest themselves, but this must change, she stressed.

Making use of such resources as the Internet is a good way of acquiring the necessary knowledge to keep pests under control, Jordan said.

“If you learn to use it properly and go to the appropriate sites that have the best information, the Internet is a wonderful source of information.”

Sports turf managers who had been subject to a municipally-imposed pesticide ban prior to the implementation of the provincial legislation have had a leg up on their counterparts from municipalities who have had to adapt for only the past two seasons.

“For a lot of municipalities, this is still relatively new.”

Although she argued pest control products that have been banned for use on sports fields are practical and useful and should not be classified as cosmetic, Jordan said they are one less option to use in an integrated pest management program.

True IPM incorporates pesticides, but sports turf managers can still proceed with the other practices of the strategy. Jordan defined IPM as a process that uses all necessary techniques to suppress pests effectively, economically and in an environmentally-friendly manner to sustain a healthy landscape.

“But you don’t have to have conventional pesticides to be part of an integrated pest management program.”

The fundamentals of prevention and stress management remain key toward incorporating an IPM program, Jordan said, adding sports turf managers must be able to communicate with and have the support of their end users. Fields may not be in the best shape for the first couple of years following the ban, and it’s important to explain to user groups why that is so.

Four key fundamentals are part of an IPM program: identification of potential pest problems, proper monitoring, stress management, and the combination of control options at the manager’s disposal.

“It’s the combination of all available options.”

Jordan said if a sports turf manager cannot properly identify a particular pest or is unsure of what to look for, he won’t be able to effectively monitor. He must also be able to identify the conditions which lead to pest issues, she added.

Weeds are generally the No. 1 problem on sports fields.

“They’re not damaging. All they are doing is filling a void. The presence of weeds suggests you have unhealthy turf or there is a void. The best way to keep weeds out is to keep turf in.”

Jordan said that because weeds fill a void, they are often an indicator that unhealthy turf is present. Among the more common weeds to be found on sports field are dandelions, plantain, clover and knotweed.

Dandelions tend to grow in maintained turf areas, especially where there is low height of cut or a particularly high height of cut. Their presence on sports fields usually depends on the level of maintenance and the level of  play.

Both broad and narrow-leafed plantain are generally present where there is low fertility, drought, a low height of cut and where there is compaction.

Clover is usually an indication of low nitrogen levels, but it can also be found where there is both drought and compaction. Because it is green in colour, some people don’t mind it as a ground cover, but its low-wear tolerance is not suited for sports fields.

Knotweed is usually present where there is compaction, low fertility and drought. An annual weed, it spreads quickly and is difficult to control. It germinates early in the season and gets a strong hold before turfgrass comes out of dormancy.

“Knotweed is a major, major issue.”

Black medic and chickweed are starting to turn up more on athletic fields. Jordan said she suspected weeds not normally seen in some time might become more prevalent with the pesticide ban firmly in place.

Insects aren’t usually as much of an issue on sports turf as weeds, but they can be damaging.

“Unlike weeds, which just fill a void and don’t necessarily damage the turf, insects absolutely damage the turf. They attack the turf and make it weaker.”

Grubs are among the most destructive insect pests. They feed on the roots of the plant near the surface, and turf managers are often unaware of their presence until it is too late.
“The nice thing about weeds is that as soon as they’re there, you can see them.”

If the sports turf manager takes the time to understand a pest insect’s lifecycle and biology, he can better predict when a problem might occur or where the insects may be found. Good monitoring can help keep a lid on potential problems.

“Unfortunately, there are very few alternative options available for insect control on athletic fields.”

Grubs are the larvae of scarab beetles. The European chafer and Japanese beetle are the adult versions of the most damaging grubs common to cool season turf. Because the juvenile stage of the insect feeds on roots, the result is wilting, thinning and irregular dead patches of turf. With the turf being sheared from its root system, the ground cover can be effortlessly pulled up like a carpet.

The European cranefly and bluegrass billbug will also cause significant damage to sports turf.

Jordan said disease isn’t as common in athletic turf as weeds and insect damage, but it can occur. If a disease is present, rapid identification is vital to prevent the fungi from spreading quickly and causing lots of damage in little time.

Two of the diseases that can affect sports turf are necrotic ring spot and rust. Necrotic ring spot affects mainly Kentucky bluegrass and fescue, but is not a threat to perennial ryegrass. It is identified by its “frog-eyed” pattern in which live green turf is present inside the ring. Excess thatch and low fertility are contributing factors toward the presence of necrotic ring spot. Use of perennial ryegrass is one means to keep the disease in check, Jordan said.

Rust is an indicator of low fertility and too much shade. Although it won’t kill the turf, it will make it weaker and more stressed out.

“The key to having a good IPM program is developing a really good monitoring program,” Jordan said.

Monitoring involves a series of inspections or counts whenever a sports turf manager or one of his staff visits a field. Written records of all observations made can help predict future pest issues.

If a record of damaging insects or weeds are observed on more than one property, “you might be able to put two and two together and figure out what the problem is or what the two share.”

It is important to know what species of turf is present in a field and where it is located, she said. A field may have started with Kentucky bluegrass, but overseeding and an invasion of annual bluegrass may produce a mix of species. Knowing what species is present and which is affected are important to know. Problems could arise with the application of too much water or not enough water.

Jordan said sports turf managers must also keep track of changing weather conditions, making particular note of temperature, humidity and rainfall. Armed with such information and noting when pest insects occur, it is possible to correlate weather conditions and when insects or weeds occur, allowing for better planning.

“Can I take these symptoms I’ve seen and correlate them to the presence of a pest?”
Visual inspections should ideally be made every time the sports turf manager or crew member is on the field, whether he’s mowing, spreading fertilizer or painting lines.
Jordan said the series of visual observations made should produce “yes” or “no” responses.

“Do I see something that is off? Do I see a colour that’s off? Is the turf different from what I’m used to seeing? Is the turf different in colour and texture? Some of these differences may mean nothing, but the more data you collect, the better the chances are of putting two and two together and figure out how management and pest presence may be correlated.”

Weak areas, for example, may suggest spots were missed when applying fertilizer.
“All of these things you should be taking note of,” she said.

If grubs are present, it is important to note if their numbers are increasing. Counting is equally important in cases of weed presence. If the number of weeds increases in a particular area, it is important to monitor the area to observe if the situation improves or gets worse.

“When visual inspections alert you to a problem, counting gives you an idea of how much of a problem it really is. The more information collected and recorded, the easier it is to prevent future problems.”

Jordan said the best way to prevent pest problems is to maintain a healthy stand of turf. Four practices critical toward maintaining healthy turf are mowing, irrigation, fertility and cultivation.

When mowing, it is good to know which type of cultivar is present on a field. Certain types of Kentucky bluegrass, for example, are meant to be mowed lower than others.
“Make sure you mow at the height that is ideal for the cultivar you have.”

When overseeding, it is important to use a cultivar that best fits within a sports turf manager’s management practices.

Deep and infrequent watering will help promote deeper root growth.

Combining shallow and deep core aeration will combat compaction better than shallow aeration alone.

Jordan said poor roots lead to decreased stress tolerance, decreased drought tolerance, decreased wear tolerance, but increases the effect of damaging insects and leads to poor competition against weeds.

Sports turf managers who are willing to better their education will have an upper hand in maintaining good athletic fields in an era of banned pesticides, she said.