BROWN PATCH


 

DESCRIPTIONS/SIGNS: Summer disease; circular patches range from a few inches to several feet in diameter. In early morning on dew-covered turf, white mycelium of the causal fungus is often visible; grass within the patch is often killed or thinned, creating a sunken effect. ENVIRONMENTAL MANAGEMENT: Avoid excess nitrogen and irrigation in summer. RESISTANT SPECIES/CULTIVARS: Kentucky bluegrass and fine fescues are the most resistant species. FUNGICIDES: Azoxystrobin, Chlorothalonil, Fenarimol, Fludioxonil, Flutolanil, Iprodione, Mancozeb, Myclobutanil, Polyoxin D Propiconazole, Pyraclostrobin, Thiophanate methyl, Thiram Triadimefon, Trifloxystrobin, Vinclozolin

DOLLAR SPOT

DESCRIPTIONS/SIGNS: White or tan spots of dead turf about the size of a silver dollar up to 4 inches in diameter. Spots may run together, producing large areas of dead turf. Leaves initially show yellow-green blothces, which progress to a light straw color with reddish-brown margins. ENVIRONMENTAL MANAGEMENT: Avoid nitrogen deficiency, drought, stress and night watering. Remove dew in early morning. RESISTANT SPECIES/CULTIVARS: Tall fescue. Some creeping bentgrass and Kentucky bluegrass cultivars are somewhat resistant. FUNGICIDES: Boscalid, Chlorothalonil, Fenarimol, Iprodione, Mancozeb, Myclobutanil, Propiconazole, Thiophanate methyl, Thiram, Triadimefon, Vinclozolin

FAIRY RINGS



 

DESCRIPTIONS/SIGNS: Typically appear as rings of dark green and fast-growing turf; may also appear as rings of slow-growing or killed turf. The bands of affected turf range from 4 inches to a foot in width, forming more or less continuing rings ranging from 3 to 200 feet across. ENVIRONMENTAL MANAGEMENT: Mask symptoms by fertilizing with nitrogen and/or iron. Thoroughly water rings to avoid drought. Core aeration and application of wetting agents may help wetting of affected soils. RESISTANT SPECIES/CULTIVARS: None available FUNGICIDES: Azoxystrobin, Flutolanil, Polyoxin D, Pyraclostrobin, Triadimefon

GRAY SNOW MOLD

DESCRIPTIONS/SIGNS: Usually noticed as the snow melts in the spring. Commonly found in turf areas with the greatest snow accumulatin; such as along driveways. Notable symptoms include white crusted areas of grass in which blades are dead, bleached and matted together. ENVIRONMENTAL MANAGEMENT: Avoid piling snow in sensitive turf areas. Remove tree leaves from turf before snow cover, Rake disease-damaged areas in spring to break up matted grass. RESISTANT SPECIES/CULTIVARS: Kentucky bluegrass, fine fescues. FUNGICIDES: Azoxystrobin, Chloroneb, Chlorothalonil, Cyproconazole, Ethazole, Fenarimol, Flutolanil, Iprodione, Propiconazole, Tridimefon, Thiram, Vinclozolin

NECROTIC RING SPOT

DESCRIPTION/SIGNS: Caused by root pathogens in cool season turfs. Symptoms include circular, ring-shaped or serpentine patches of dead or dying turf. Affected areas may be a few inches to a foot or more in diameter. Seldom occurs in newly planted turf, but can appear on recently sodded turf. ENVIRONMENTAL MANAGEMENT: Use cultural practices that reduce turf stress, such as irrigation; raise mowing heights to 2 inches or more. RESISTANT SPECIES/CULTIVARS: Perennial ryegrass, tall fescue FUNGICIDES: Azoxystrobin, Fenarimol, Iprodione, Myclobutanil, Propiconazole, Thiophanate methyl

PINK SNOW MOLD / MICRODOCHIUM PATCH

DESCRIPTION/SIGNS: Develops under snow cover. Gets its name from the accumulation of pink fungal spores that pile up on the leaves of infected grass plants, producing a pink cast on circular patches of matted grass. ENVIRONMENTAL MANAGEMENT: Avoid piling snow in sensitive turf areas. Continue mowing turf in fall until growth ceases. Do not apply excessive amounts of nitrogen in mid-fall. RESISTANT SPECIES/CULTIVARS: Kentucky bluegrass and fine fescues are less susceptible than creeping bentgrass or perennial ryegrass. FUNGICIDES: Azoxystrobin, Chlorothalonil, Fenarimol, fludioxanil, Ipordione, Mancozeb, Myclobutanil, Propiconazole, Pyraclostrobin, Thiophanate methyl, Thiram, Triadimefon, Trifloxystrobin, Vinclozolin

POWDERY MILDEW

DESCRIPTION/SIGNS: First appears as isolated wefts of fine, gray-white powdery growth on the upper surface of the grass leaf; it becomes rapidly more dense and may cover the entire leaf, giving it a gray-white appearance. ENVIRONMENTAL MANAGEMENT: Don't grow Kentucky bluegrass in shaded areas. Prune trees to allow more light. RESISTANT SPECIES/CULTIVARS: Fine fescues; use shade-tolerant ground covers in shaded areas. FUNGICIDES: Fenarimol, Myclobutanil, Propiconazole, Triadimefon

PYTHIUM BLIGHT

DESCRIPTION/SIGNS: Also known as grease sot and cottony blight, it can be highly destructive, especially on bentgrasses and ryegrasses. First appears as small, irregularly shaped spots ranging from 1/2 inch to 4 inches in diameter. Leaves appear water-soaked in appearance, then shriveled. Patches fade to light brown or gray; groups of spots may join together. ENVIRONMENTAL MANAGEMENT: Avoid excessive nitrogen and irrigation in hot, humid weather. Improve drainage and air circulation in areas where the disease is a problem. RESISTANT SPECIES/CULTIVARS: Kentucky bluegrass is less susceptible than perennial ryegrass and creeping bentgrass. FUNGICIDES: Azoxystrobin, Chloroneb, Ethazole, Fosteyl-Aluminum Mefnoxam, Metalaxyl, Potassium phosphate, Propamocarb, Pyraclostrobin

RUST DISEASES

DESCRIPTION/SIGNS: A number of rust diseases affect turf; they generally appear as a light yellow flecking of the leaves. As flecks enlarge, they may become longer than broad and when numberous, they are arranged in rows parallel with the veins of the leaves. Severe outbreaks may appear similar to rusty iron. ENVIRONMENTAL MANAGEMENT: Avoid nitrogen deficiencies and moisture stress in late summer/early fall. Applications of nitrogen fertilizer and irrigation at the first sign of infection will help reduce disease severity. RESISTANT SPECIES/CULTIVARS: Fine fescues and tall fescue are quite resistant to most foliar rust diseases. FUNGICIDES: Azoxystrobin, Chlorothalonil, Cyproconazole Fenarimol, Mancozeb, Myclobutanil, Propiconazole, Pyraclostrobin, Tridimefon, Trifloxystrobin

SLIME MOLDS

SUMMER PATCH

DESCRIPTION/SIGNS: Sometimes called Poa patch, occurs on Kentucky bluegrass and fine fescues on lawns. Symptoms appear identical to necrotic ring spot; seek expert diagnostic assistance. ENVIRONMENTAL MANAGEMENT: Use cultural practices that promote root growth. Increase aeration and improve drainage. RESISTANT SPECIES/CULTIVARS: Perennial ryegrass, tall fescue and creeping bentgrass. FUNGICIDES: Azoxystrobin, Fenarimol, Myclobutanil, Propiconazole, Thiophanate methyl, Triadimefon, Trifloxystrobin