Monthly Archives: September 2018

Slime Mold – Pest or Not?

“A word is worth a thousand pictures, if it is the right word. Risk is the right word.” – Michael Hoff, PhD

When a problem presents itself, the first step should often be to determine whether it really is a problem. In other words, does it create a risk? At times, something may look scary, but may actually be eating other insects that are pests (house centipedes are a great example of this). Slime mold, a fungus-like organism, showing up in a school playground recently brought up the question of risk and how to react to it.

No one wants to walk out of their building and see this. Photo: Doug Beckers flickr

From the Plant Disease Diagnostic Clinic fact sheet:  “Slime molds are frequently observed when they form large colonies on mulch around trees or shrubs. They may initially appear as a slimy mound or mass, come in a variety of colors, and are often unsightly.”

Unsightly indeed. It is often called dog vomit mold.

So a school was very concerned when it started popping up throughout the playground mulch. They began making phone calls which led to us. We were able to reassure them that slime mold feeds only on bacteria in the mulch and there are no known health risks associated with them.

Slime mold crusts over after it finishes with its mobile stage. Still unattractive.

Human health risk usually reaches the highest tier of concern for risk assessment. Given the low risk, the school could just wait it out until the weather changes. Slime mold thrives under hot and humid conditions. Cool, dry weather would take care of the issue. It’s a good reminder that many pests (or, in this case, non-pests) are weather related and checking the forecast can help us determine how long the issue might last.

A change in the weather is sufficient to recreate the world and ourselves. – Marcel Proust

It’s worth noting that there are no pesticides registered in New York to manage slime mold on mulch. Any use of a pesticide would not only be illegal, but would also cause its own unnecessary risk.

There is another concern that falls lower down on the list, but is still important – perception of risk. In this case, there was a concern about how parents of young children would react to the unsightly mounds. To address this concern, we recommended shoveling out the visible slime mold and hosing down the area to disperse residual materials. And reminded them that as long as the weather remained hot and humid, slime mold would continue to pop up, so keep the shovel at hand.

A unrealistic perception of risk can also be addressed through education. So we found this nifty video about these fascinating organisms and how they move. Check out this Deep Look video from PBS. Talk about a teachable moment!

Have a question on managing pests in your school or childcare facility? Visit our Schools and Daycare Centers webpage.

Managing traffic is IPM

Are you interested in turfgrass management? Especially as it relates to sports fields? Then the ShortCUTT (Cornell University Turfgrass Times) newsletter, written by Associate Professor and Extension Turfgrass Specialist, Dr. Frank Rossi, is for you! Check out a segment of this week’s offerings.
To receive a copy of the weekly newsletter, e-mail program manager, Carl Schimenti at css223@cornell.edu. Prefer your information verbally? Subscribe to the weekly Turf Talk podcast.

Frequently Asked Questions:

In the simplest of terms, the more use a field receives, the more preparation it will need prior to the initiation of use, maintenance during the traffic period, and recovery maintenance following the traffic. Photo: Bob Portmess

My fields are showing wear stress already after three weeks of use as a result of rainy and now very warm conditions. I’m trying to speak with coaches and parents about field use under these conditions. They keep asking the same question of me, “how many hours of use CAN the field handle”? Can you help?

First big kudos for recognizing the need to communicate with your clients regarding the conditions and safety of the fields. Effective communication is the consistent characteristic of successful professional sports turf managers. We have provided some useful tools to assist with the general information for players, parents, coaches and athletic directors at http://safesportsfields.cals.cornell.edu/coaches.

Additionally, there will not be any hard fast answer to the question without some qualification and understanding of the root zone, type of use, maintenance inputs, and visual quality expectations.

Our first responsibility is to ensure player safety as measured by field hardness, evenness and traction; other field issues become subjective as to what constitutes an “acceptable playing surface”. Again, there are gray areas when discussing amount of use, as poor weather experienced over the last 30 days has led to significantly more wear stress and field decline than expected under average weather patterns. Finally, larger amounts of managed field area that allows for dispersal of focused traffic and the availability of synthetic surfaces both significantly increase overall amount of natural grass playing field use.

Rootzones:

Soil properties impact traffic tolerance.

Loamy soil root zones with some drainage and some irrigation can withstand more than the average amount of use. Sand-based fields with excellent drainage can withstand significantly more than the average amount of use.

Type of Use:

Any type of field use that results in repetitive focused traffic, i.e., between the hash marks, goal mouths, sidelines, will reduce the amount of field use. Larger male athletes create more traffic stress than lighter female athletes. Youth sports with smaller athletes and smaller field dimensions that can be rotated, allow for much more use than average. Again rotation allows for dispersal of the traffic.

Schools and community parks are able to provide different levels of field maintenance based on their budget and the resources on hand that include labor (knowledge and experience), equipment and products. Other factors play into shifting resources, such as desired quality, type of field and use (practice vs game fields).

Maintenance Inputs:

Reasonable care of fields is expected as outlined in ASTM F2060 for cool season natural grass fields – this will include some amount of field rest and recovery as outlined in these important maintenance schedules. In the simplest of terms, the more use a field receives, the more preparation it will need prior to the initiation of use, maintenance during the traffic period, and recovery maintenance following the traffic. No maintenance program will compensate for overuse that leads to decline in field quality below acceptable levels and will need a routine turf replacement program as seen in most professional sporting venues.

Visual Quality Expectations:

A soft, bright green field with poor traction is less safe than a slightly brown, firm, even surface. Photo: Joellen Lampman

Players, coaches, parents and Athletic Directors have the right expect to safe playing fields. Sports turf managers must have field safety measurements to effectively determine when field use leads to decline in safety. The visual quality of the field often is correlated to field safety but not always, as a soft bright green field with poor traction is less safe than a slightly brown firm even surface.

In the end, general guidelines suggest good field conditions can be maintained with reasonable care at between 400-600 hours of use per year per field. Beyond 600 hours of use expect a loss in field quality and significant thinning and wear areas even under ideal conditions.

 

Many thanks to Frank Rossi for providing permission to share this information. For more information on sports field management, visit the Cornell Turfgrass page on Sports Turf and the New York State Integrated Pest Management page on Landscapes, Parks, and Golf Courses.