A-N - Guide for the Management of Turfgrass Diseases

A to N - Guide for the Management of Turfgrass Diseases.

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

Disease: Algae.

• Susceptible Turfgrass: All turfgrasses.
• Season: July-August - North America.
• Maintenance Practices: 1) Reduce shade; 2) Avoid excessive or low fertilisation; 3) Improve soil drainage; 4) Alleviate compaction; and 5) Mow high to increase density.
• Fungicide/Nematicide - Active Ingredient: Mancozeb, Chlorothalonil.

Disease: Anthracnose (Colletotrichum graminicola).

• Susceptible Turfgrass: ANNUAL BLUEGRASS, Bentgrass, Fine Fescue.
• Maintenance Practices: 1) Fertilise and water to maintain vigour; and 2) Aerate and improve root growth.
• Fungicide/Nematicide - Active Ingredient: Triadimefon, Thiohanate-methyl3, Propiconizole, Fenarimol, Cyproconazole, Azoxystrobin.

Disease: Brown Patch - See Rhizoctonia Blight.

• Season: Late June-October - North America.

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

• Susceptible Turfgrass: BENT GRASSES, BLUEGRASSES, Fescues, Ryegrass.
• Maintenance Practices: 1) Avoid nitrogen deficiency; 2) Remove dew from greens by dragging with a hose or pole; and 3) Choose resistant grass varieties.
• Fungicide/Nematicide - Active Ingredient: Chlorothalonil, Vinclozolin3, Fenarimol, Iprodione3, Propiconizol, Cyproconazole, Thiophanate-methyl3, Thiram, Triadimefon, Myclobutanil.

Disease: Fairy Rings (Basidiomycete soil fungi).

• Susceptible Turfgrass: BENT GRASSES, BLUEGRASSES, Fescues, Rye grasses.
• Season: April-October - North America.
• Maintenance Practices: 1) Remove infested sod and soil, replace with clean soil and reseed or sod; 2) Improve water penetration; and 3) Increase nitrogen fertilisation to mask symptoms.
• Fungicide/Nematicide - Active Ingredient: Methyl bromide fumigation will eradicate fungus but will also kill turf. Flutolanoil.

Disease: Fusarium Blight - see Necrotic Ring Spot and Summer Patch.

Disease: Fusarium Patch - see Pink Snow Mold/ Fusarium Patch.

Disease: Gray Snow Mould/ Typhula Blight (Typhula spp.).

• Susceptible Turfgrass: BENT GRASSES, ANNUAL BLUEGRASS, Fine Fescue, Tall Fescue, Kentucky Bluegrass, and Perennial Ryegrass.
• Season: November-April - North America.
• Maintenance Practices: 1) Avoid heavy fall nitrogen promoting late lush growth; 2) Rake leaves and cut short; and 3) Control drifting snow.
• Fungicide/Nematicide - Active Ingredient: Triadimefon, Chloroneb, Pentachloronitrobenzene, Thiram, Cyproconazole, Iprodione3, Iprodione + Chlorothalonil, Flutolanil, Azoxystrobin.

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

• Susceptible Turfgrass: KENTUCKY BLUEGRASS, BENT GRASSES, FINE FESCUE, Rye grasses, Tall Fescue.
• Season: April-October - North America.
• Maintenance Practices: 1) Raise cutting height; 2) Avoid excessive nitrogen; 3) Avoid light, frequent watering; and 4) Avoid excessive herbicide.
• Fungicide/Nematicide - Active Ingredient: Iprodione3, Chlorothalonil, Maneb, Mancozeb, Vinclozolin3, myclobutanil, Pentachloronitrobenzene, Azoxystrobin.

Disease: Nematodes.

• Susceptible Turfgrass: All turfgrasses.
• Season: Summer & Fall/Autumn
• Maintenance Practices: 1) Avoid low mowing heights (below 2 inches); 2) Reduce excessive thatch (over 3/4 inch), compaction and frequently aerate; 3) Use Kentucky bluegrass and perennial ryegrass mixtures; 4) Improve soil drainage; 5) Avoid excessive watering or drought stress; and 6) Use slow release nitrogen.
• Fungicide/Nematicide - Active Ingredient: Fenamiphos, Ethoprop

Disease: Necrotic Ring Spot4 (Leptosphaeria korrae).

• Susceptible Turfgrass: KENTUCKY BLUEGRASS (especially 3-4 year old sod), Annual Bluegrass, Fine Fescue.
• Season: Spring to Fall/Autumn.
• Maintenance Practices: 1) Avoid low mowing heights (below 2 inches); 2) Reduce excessive thatch (over 3/4 inch), compaction and frequently aerate; 3) Use Kentucky bluegrass and perennial ryegrass mixtures; 4) Improve soil drainage; 5) Avoid excessive watering or drought stress; and 6) Use slow release nitrogen.
• Fungicide/Nematicide - Active Ingredient: Fenarimol, Propiconizol, Iprodione3, Thiophanate-methyl3, Cyproconazole, Myclobutanil, Azoxystrobin.

Products containing these active ingredients are listed in Trade Names for Turfgrass Fungicides and Nematicides. Read the product label to see if it is labeled for the disease of concern. The degree of control may vary with different products.

Continued or sole use of these materials may favour buildup of resistant fungal population.

Necrotic ring spot and summer patch are known to cause symptoms once attributed solely to Fusarium blight.

Pink patch is a distinct disease from red thread. There are few fungicides specifically registered for control of pink patch.

Another fungus, Rhizoctonia zeae, is also capable of causing brown patch-like symptoms on bluegrass and bentgrass. Benzimidazole fungicide (Thiophanate-methyl) is not effective against this pathogen.