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Ohio STMA Field Day addresses soils, disease and special events

June 26, 2015  - By


The Ohio Sports Turf Managers Association held its annual Summer Field Day at the Cleveland Browns’ training facility and at First Energy Stadium on June 24.

Along with tours of the practice facility in Berea, Ohio, and of the stadium downtown, three experts gave presentations on various turgrass-related topics in the film room at the training facility.

Joe Rimelspach, Ph.D., program specialist (extension, turfgrass pathology) at The Ohio State University, shared how to manage gray leaf spot (GLS) and summer patch; Beth Guertal, alumni professor at Auburn University, spoke about soils; and Chris Ecton, sports turf manager for the Pittsburgh Steelers, talked about managing non-athletic events on your field.

Rimelspach’s discussion was focused mostly on GLS. He emphasized that GLS may look like drought conditions, but watering creates a perfect storm for GLS, which thrives in wetness and humidity. He recommends completely changing the turf to a GLS-resistant grass or viewing Rutgers Cooperative Extension’s GLS fact sheet.

Rimelspach handed out a chart compiled by himself and his associates. The table below, provided by Rimelspach, addresses infectious diseases caused by fungal pathogens, and can be used as a reference for sports turf managers.

This chart was made by Joseph W Rimelspach, Todd E. Hicks and Francesca Peduto Hand from the department of plant pathology at The Ohio State University. Click here to access the original chart in PDF format.
(Pathogen name, the fungus)
(All capital letters indicate most commonly affected.)
(Signs are the fungus or a part of the fungus,
symptoms are the result of the infection on the
plant, abnormal appearance or growth.)
(Temperature and
moisture conditions that
favor disease development)
(This is the first line of defense and tool to manage disease. After these have been implemented and depending on the circumstances, then fungicide applications are considered.)
Brown Patch/
Rhizoctonia Blight
(Rhizoctonia solani)
Kentucky bluegrass
Fine Fescue
– Irregular to circular patches (6”-2’)
– Patches variable shades of tan to brown
– Outer edges of patch may be darker
– Irregular shaped lesions on leaves
– Gray to white fungal growth may be
present when turf wet and high humidity
– May be confused with Pythium blight
Days > 80 to mid 90s and warm nights, mid
60s +. Abundant water, wet soils.
1) Avoid excessive Nitrogen fertilization.
2) Avoid excessive watering and poor drainage.
3) Increase air circulation by removing surrounding vegetation and increase sun light.
4) Manage to prevent lush succulent turfgrass plants.
Dollar Spot
(Sclerotinia homoeocarpo)
Fine Fescues
Perennial Ryegrass
– Circular tan patches/spots (1-6”)
– Leaf lesions light tan with dark edges
– Leaf lesions go across leaf blade (a band)
– White fungal growth may be present in
early morning when dew present
Moderate days 60 to low 80s
Prolonged periods of wet leaves.
Dry Soil – slow leaf growth so poor
recovery from damage
1) Avoid Nitrogen deficiency.
2) Choose resistant grass varieties.
3) Manage watering to minimize time leaves are wet.
4) Water to increase growth.
Fairy Ring
(Soil borne Basidiomycete
All Turfgrasses – Dark green or brown circles (1-10+’)
– Grass in dark green ring may grow taller
– Rings may turn brown and die
– Mushrooms may grow in the ring
– A white fungal mat may be present in the
thatch area of the ring and smells musty
Grow over a wide range of temps. And soil
moisture conditions, often favored by moist
soils. Brown turf may develop in prolonged
hot dry periods.
1) Improve water penetration; aeration, deep watering and
wetting agents.
2) Remove infected soil and sod; replace with clean soil and sod or seed.
Gray Leaf Spot
(Pyricularia grisea)
Tall fescue (in S.E. USA)
St. Augustinegrass (in S. USA)
– Starts as v. small dark spots/flecks
– Leaves often quickly wither and die
– Irregular patches to large areas die
– Only P. ryegrass affected, other grasses
and weeds are not affected
– No fungus (mold) is found on plants
Prolonged hot humid weather patterns in
late summer and fall, long summer stress
conditions for cool season grasses. Moist
soils (turf may appear wilted but soil
1) Plant resistant varieties or avoid P. ryegrass.
2) Avoid lush turfgrass, use moderate fertilization.
3) Manage watering to minimize time leaves are wet.
4) Use resistant grass species.
5) Minimize turf stress; reduce compaction, avoid chemical
injury (herbicides).
Leaf Spot/Melting Out
(Drechsler & Bipolaris spp.)
(Common bluegrasses)
Fine fescue
– Initially very small dark spots on leaves
– Spots enlarge in size
– Center of spots may be a lighter brown
– Leaf sheaths can be entirely
– Crowns rot, turf thins (“melting out”)
Leaf Spot-Cool/Wet
Melting Out/Hot Dry
(Leaf Spot: spring & fall,
Melting Out: summer)
1) Raise cutting height.
2) Mow frequently to avoid stressing turf.
3) Avoid excessive nitrogen.
4) Avoid frequent watering and wet turf.
Powdery Mildew
(Erysiphe graminis)
Fine Fescue
– White or gray colored powdery
appearance to leaf surface (does not easily
rub off)
– Leaves may yellow and turf stand thin
Moderate/High humidity
Areas of poor air circulation
1) Reduce shade.
2) Increase air circulation.
3) Use resistant Kentucky bluegrass varieties.
Pythium Blight
(Pythium species)
Kentucky bluegrass
(Rather uncommon on mature
high cut turfgrasses)
– May start as small dead spots
– Leaves often look dark/black/greasy
– Fluffy gray to white ‘cottony’ fungus may
be present when disease is active
– Spots may run together and have an
irregular shape, turf quickly dies, brown
– May be confused with brown patch
V. Hot/Wet
(This is a water mold, abundant water is
(Days high 80s to 90s ++ and warm nights
70 and above.)
Often found in low wet areas, with poor
1) Improve soil drainage.
2) Increase air circulation by removing surrounding
3) Avoid excess watering.
4) Avoid high rates of Nitrogen.
5) New seedling often affected in hot wet conditions.
Red Thread
(Laetisaria fusiformis)
Kentucky bluegrass
Tall Fescue & Bentgrass
– Patches appear as tan, light pink or reddish
– Leaf tips and edges of leaves have fine
pink or red strains of fungus present
– Size of patches variable (2-12”)
Moderate/Wet Foliage
Prolonged periods of wet leaves
1) Follow a complete fertilization program, avoid
deficiencies in nitrogen and phosphorous.
2) Promote growth by aeration, watering, etc.
3) Use resistant varieties.
(Puccini species)
(Some varieties of Key bluegrass
are susceptible, some resistant)
– Starts as small yellow flecks on leaves
– Flecks enlarge, to form rust colored raised
spots (pustules, spores rubs off on shoes…)
– Over all turf yellows and thins
Moderate/Wet Foliage, Dry Soil
(Dry Soil – slow leaf growth so poor
recovery from damage.)
1) Avoid Nitrogen deficiency.
2) Use resistant varieties of Kentucky bluegrass &
perennial ryegrass.
3) Water if dry, promote growth.
Slime Mold
(Myxomycete species)
All Turfgrasses – Small pin head size balls/ debris on leaves,
vary in color yellow, white, gray, purple, etc.
– Cosmetic problem , rubs off leaves
Moderate to warm temperatures/
Prolonged wet foliage
1) Mechanically remove by raking or mowing. (Causes no
injury, only cosmetic.)
Snow Mold / Pink
(Microdochium nivale)
Perennial Ryegrass
Kentucky bluegrass
– Infected grass in patches, bleached, matted
– Grass appears slimy when wet
– Patches may run together to form large
irregular affected areas
– Crowns are often alive for recovery.
Cool wet winters. Saturated, unfrozen, soil
for long periods is ideal.
No snow required.
Occurs in winter and spring.
1) Avoid lush turf in winter, keep mowing to prevent long
turf in winter.
2) Rake leaves.
3) Control drifting snow, prevent piles of snow.
Summer Patch (Magnaporthe poae)
Necrotic Ring Spot
(Ophiosphaerella korrae)These are Patch Diseases
Fine fescue
– Begins as dark wilted spots like drought
stress (1-3”) and enlarge to patches
(about 12’ in diameter)
– Shapes are variable, crescents, streaks etc.
– Outer edge of circles/patches are brown
with green centers are common.
– Crowns and roots usually die.
Warm/Extremes in soil moisture
(Fluctuating wet to dry)
Poor quality soil, compacted, clay, buried
stone and debris, etc.
– Usually occurs on sodded lawns with poor
site preparation (the turf has a weak or
limited root system).
1) Avoid low mowing & thatch buildup.
2) Maintain soil pH between 6 & 7.
3) Frequent watering when dry to avoid stress.
4) Use very slow-release fertilizer.
5) Renovate the damaged areas with resistant grasses.
6) Difficult to manage with fungicides.
*For fungicide recommendations check with county cooperation extension officer and State Land Grant University in your area.

Guertal focused on the importance of aeration, in whichever form that may be. She shared studies she and her students performed, including core aeration, solid tine aeration and vertical mowing. In one study, the data collected showed that all forms of aeration resulted in higher porosity of the soils than of the soils left untreated.

The presentation by Ecton focused on how to bounce back from possible damage from non-athletic events on fields, such as concerts, NHL events, marathons, kids’ days and — in Heinz Field’s case — a movie scene. Producers “blew up” Heinz Field in 2011 for the Batman movie “The Dark Knight Rises” — only after, of course, promising to pay for a new field installation following the damage.

Following many photos shown of damage to the field caused by non-athletic events, one of about 50 attendees in the audience asked Ecton how he handles the stress.

“I try not to let it get to me,” Ecton says while queuing up a photo of himself with a banged-up, bloodied forehead. “It doesn’t matter so much what you say… The outcome will be what it is, and you have to go with it. Whatever happens, it’s not as bad as this [photo].”

Next year’s date and location Ohio STMA Summer Field day is TBA.

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About the Author:

Harms is the Digital Media Content Producer for North Coast Media. She completed her undergraduate degree at Ohio University, earning a Bachelor of Science in Journalism and Creative Writing Specialization from the E.W. Scripps School of Journalism. Harms specifically creates content for NCM’s Golfdom, GPS World, Geospatial Solutions and Athletic Turf digital properties including eNewsletters, social media and websites. She can be reached at

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