Turfgrass Diseases

Controlling Turfgrass Diseases

Much of the information below comes from Ohio State University. Our thanks to their research. If you have additional information that you think should be included, or links that would be helpful, please let us know.

View photos of various turfgrass diseases.

Summer Patch Disease Photos


Algea Fusarium Patch Powdery Mildew Slime Molds
Anthracnose Gray Snow Mold Pythium Blight Stripe Smut
Blight Leafspot Pythium Root Rot Summer Patch
Brown Patch Melting Out Red Leaf Spot Take-all Patch
Dollar Spot Nematodes Red Thread Typhula Blight
Downy Mildew Necrotic Ring Spot Rhizoctonia Blight Yellow Patch
Fairy Rings Pink Patch Rust Yellow Tuft
Fusarium Blight Pink Snow Mold Snow Mold - see
  Fusarium Patch and
  Typhula Blight



Algea

Susceptibles Turfgrasses: All
Cultural Control: Reduce shade, Avoid excessive fertilization, Improve soil drainage.
Fungicide/Nematicide (Active Ingredient): Mancozeb

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Anthracnose (Collectotrichum graminicola)

Season: July-Aug.
Susceptibles Turfgrasses: ANNUAL BLUEGRASS1, Bentgrass, Fine fescue
Cultural Control: Fertilize and water to maintain vigor, Aerate and improve root growth.
Fungicide/Nematicide (Active Ingredient): Benomyl2, Triadimefon,Thiohanate-Methyl2, Propiconizol, Fenarimol, Cyproconazole

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Dollar Spot (Lanzia and Moellerodiscus, spp. formerly Sclerotinia homeocarpa)

Season: June-Oct.
Susceptibles Turfgrasses: BENTGRASSES1, BLUEGRASSES1, Fescues, Ryegrasses
Cultural Control: Avoid nitrogen deficiency, Remove dew from greens by dragging with a hose or pole, Choose resistant grass varieties.
Fungicide/Nematicide (Active Ingredient): Chlorothalonil, Cadmium2, Benomyl2, Anilizine2, Fenarimol, Iprodione2, Propiconizol, Cyproconazole, Thiophanate-methyl2, Thiram, Triadimelon, Vinclozolin2

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Fairy Rings (basidiomycete soil fungi)

Season: April-Oct.
Susceptibles Turfgrasses: BENTGRASSES1, BLUEGRASSES1, Fescues, Ryegrasses
Cultural Control: Remove infested sod and soil, replace with clean soil and reseed or sod; Improve water penetration; Increase nitrogen fertilization to mask symptoms.
Fungicide/Nematicide (Active Ingredient): Methyl bromide or Formaldehyde fumigation will eradicate fungus but will also kill turf. Flutolanoil

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Fusarium Blight3 (Fusarium Poae F.culmorum, F. crookwellenese)

Season: July-Aug.
Susceptibles Turfgrasses: All Turfgrasses
Cultural Control: Reduce heat stress during dry periods by light, frequent watering; Do not cut Kentucky bluegrass or fescues under 2 inches; Reduce excessive thatch(over 3/4-inch).
Fungicide/Nematicide (Active Ingredient): NONE

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Fusarium Patch/Pink Snow Mold (Microdochium nlvale)

Season: Nov.-April
Susceptibles Turfgrasses: Bluegrasses, Bentgrasses, Fescues, Ryegrasses
Cultural Control: Avoid excessive late fall fertilizing, Rake leaves and mow short, Control drifting snow.
Fungicide/Nematicide (Active Ingredient): Triadimefon, Fenarimol, Iprodione2, Mancozeb, Mercury chlorides, Pentachloronitrobenzene, Thiram, Thiophanate-methyl2, Vinclozolin, Cyproconazole

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Leafspot/Blight/Melting Out(Drechsler & Bipolaris spp.)

Season: leafspot: Spring & Fall
Blight & melting out;June-Aug.
Susceptibles Turfgrasses: KENTUCKY BLUEGRASS1, BENTGRASSES1, FINE FESCUE1, Ryegrasses, Tall fescue
Cultural Control: Raise cutting height, Avoid excessive nitrogen, Avoid light, frequent watering.
Fungicide/Nematicide (Active Ingredient): Iprodion, Chlorothalonil, Maneb, Mancozeb, Vinclozolin, Anilizine, Pentachloronitrobenzene

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Nematodes

Season:
Susceptibles Turfgrasses: All Turfgrasses
Cultural Control:
Fungicide/Nematicide (Active Ingredient): Fenamiphos, Ethoprop.

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Necrotic Ring Spot3 (Leptosphaeria korrae)

Season: Spring & Fall
Susceptibles Turfgrasses: KENTUCKY BLUEGRASS1, Annual bluegrass, Ryegrasses,
Cultural Control: Avoid low mowing heights(below 2 inches), Reduce excessive thatch (over 3/4 inch), Use Kentucky bluegrass and perennial ryegrass mixtures, Improve soil drainage, Avoid excessive watering or drought stress.
Fungicide/Nematicide (Active Ingredient): Fenarimol, Propicontzol, Iprodione, Thiophanate-methyl, Cyproconazole

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Pink Patch4 Limonomyces roseipellis)

Season: Spring & Fall
Susceptibles Turfgrasses: Bentgrasses, FINE FESCUE1, PERENNIAL RYEGRASS1
Cultural Control: Follow balanced fertilization program.
Fungicide/Nematicide (Active Ingredient): Cadmium, Mancozeb, Flutolanil

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Powdery Mildew (Erysiphe graminis)

Season: July-Oct.
Susceptibles Turfgrasses: KENTUCKY BLUEGRASS1, Fine fescue.
Cultural Control: Reduce shade, Increase air circulation by removing surrounding vegetation, Use resistant Kentucky bluegrass.
Fungicide/Nematicide (Active Ingredient): Triadimefon, Fenarimol, Propiconizol, Cyproconazole

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Pythium Blight (Pythium aphanidermatum, P. graminicola)

Season: June-Sept.
Susceptibles Turfgrasses: BENTGRASSES1, ANNUAL BLUEGRASS1, PERENNIAL RYEGRASS1, Kentucky bluegrass.
Cultural Control: Improve soil drainage, Increase air circulation by removing surrounding vegetation, Avoid mowing wet grass, Avoid excess watering.
Fungicide/Nematicide (Active Ingredient): Chloroneb, Etridiazole, Propamocarb, Metalaxyl, Fosetyl-A1, Mancozeb

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Pythium Root Rot (Pythium)

Season: Spring & Fall
Susceptibles Turfgrasses: ANNUAL BLUEGRASS1, BENTGRASSES1
Cultural Control: Improve soil drainage, Increase mowing height.
Fungicide/Nematicide (Active Ingredient): Metalaxyl, Propamocarb. Apply Oct.-Nov., water in thoroughly.

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Red Leaf Spot(Drechslera erythrospila)

Season: June-Sept.
Susceptibles Turfgrasses: BENTGRASSES1
Cultural Control: Remove clippings, Fertilize to maintain vigor.
Fungicide/Nematicide (Active Ingredient): Iprodione, Anilizine, Vincolozolin, Chlorothalonil

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Red Thread4 (Laeslisaria fuciformis)

Season: All seasons
Susceptibles Turfgrasses: PERENNIAL RYEGRASS1, FINE FESCUE1, Bentgrasses, Annual bluegrass, Kentucky bluegrass.
Cultural Control: Follow balanced fertilization program; Promote growth by aeration, watering, etc.
Fungicide/Nematicide (Active Ingredient): Vinclozolin, Flutolanil, Chlorothalonil, Cyproconazole, Thiophanate-methyl, Mancozeb, Triadimefon, Propiconizol, Iprodione

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Rhizoctonia Blight/Brown Patch5 (Rhizoctonia solani, -Thanatephorus cucumeris)

Season: July-Aug.
Susceptibles Turfgrasses: BENTGRASSES1, ANNUAL BLUEGRASS1, TALL FESCUE1, Kentucky bluegrass, Fine fescue.
Cultural Control: Avoid excessive nitrogen fertilization; Increase air circulation by removing surrounding vegetation; Avoid excessive watering.
Fungicide/Nematicide (Active Ingredient): Anilizine, Chlorothalonil, Mancozeb, Maneb, Propiconizol, Pentachloronitrobenzene, Thiram Triadimefon, Thiophanate-methyl2 Cyproconazole, Iprodione

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Rust (Puccinia spp)

Season: Aug.-Oct.
Susceptibles Turfgrasses: PERENNIAL RYEGRASS1, KENTUCKY BLUEGRASS1
Cultural Control: Avoid nitrogen deficiency; Use resistant varieties of Kentucky bluegrass and perennial ryegrass; water if dry, promote growth.
Fungicide/Nematicide (Active Ingredient): Mancozeb, Propiconizol, Cyproconazole, Chlorothalonil, Triadimefon, Fenarimol

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Slime Molds (Myxomycete)

Season: Aug.-Sept.
Susceptibles Turfgrasses: All turfgrasses
Cultural Control: Remove mechanically by mowing or raking.
Fungicide/Nematicide (Active Ingredient): Zmeb, Mancozeb

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Stripe Smut (Ustilago striiformis)

Season: Spring & Fall
Susceptibles Turfgrasses: KENTUCKY BLUEGRASS1, bentgrasses
Cultural Control: Avoid drought stress; Avoid excess nitrogen; Use resistant varieties of Kentucky bluegrass.
Fungicide/Nematicide (Active Ingredient): Propiconizol, Triadimefon, Benomyl, Thiophanate-ethyl Fenarimol, Cyproconazole, Note: Apply extra water for crown penetration. Apply in late fall or early Spring.

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Summer Patch3 (Magnaporthe poae, formerly Phialophora graminicola)

Summer Patch Disease Photos

Season: June-Aug.
Susceptibles Turfgrasses: ANNUAL BLUEGRASS1, KENTUCKY BLUEGRASS1, Fine fescue
Cultural Control: Avoid low mowing and thatch buildup; Maintain soil pH between 6 & 7; Light, frequent watering during dry periods to reduce heat stress; Use slow-release nitrogen; Use Kentucky bluegrass and perennial ryegrass mix.
Fungicide/Nematicide (Active Ingredient): Fenarimol, Triadimefon, Propiconizol, Cyproconazole Note: Materials must be applied preventively.

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Take-all Patch (Gaeumannomyces graminis)

Season: Spring & Fall
Susceptibles Turfgrasses: BENTGRASSES 1
Cultural Control: Use acidifying fertilizers to lower pH; Avoid heavy rates of lime;Remove patches and resod.
Fungicide/Nematicide (Active Ingredient): Fenarimol, Phenylmecuric acetate.

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Typhula Blight/Gray Snow Mold (Typhula spp.)

Season: Nov.-April
Susceptibles Turfgrasses: Fine fescue, BENTGRASSES1, ANNUAL RYEGRASS1, Kentucky bluegrass, Tall fescue, Perennial ryegrass. 1
Cultural Control: Avoid heavy Fall nitrogen promoting late lush growth; Rake leaves and cut short; Control drifting snow.
Fungicide/Nematicide (Active Ingredient): Triadimefon, Cadmium, Chloroneb, Anilizine, Pentachloronitrobenzene, Mercury Chlorides, Thiram, Iprodione, Iprodione+, Chlorothalonil, Flutolanil, Cyproconazole.

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Yellow Patch (Rhizoctonia cerealis)

Season:
Susceptibles Turfgrasses: Bluegrasses, Bentgrasses
Cultural Control: Reduce excessive thatch; Avoid excessive watering; Improve soil drainage.
Fungicide/Nematicide (Active Ingredient): Flutolanil

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Yellow Tuft/Downy Mildew

Season: Spring & Fall
Susceptibles Turfgrasses: Bentgrasses
Cultural Control: Improve soil and surface drainage.
Fungicide/Nematicide (Active Ingredient): Metalaxyl, Fosetyl-A1

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Footnotes

1 Grass types listed in capital letters have been observed to be especially susceptible to the pathogen.

2 Continued or sole use of these material may favor buildup of resistant fungal population.

3 Necrotic Ring Spot and Summer Patch are known to cause symptoms once attributed solely to Fusarium blight.

4 Pink Patch disease was recently found to be a disease distinct from red thread. Thus, there are few fungicides specifically registered for control of this disease at this time.

5 Another fungus Rhizoaonia zeas, is also capable of causing brown patch-like symptoms on bluegrass and bentgrass,. Benzimidazole-type fungicides are not effective against this pathogen.