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1981 EC81-1235 Turfgrass Disease Damage Prevention and Control ; A Common Sense Approach Arthur H. Bruneau

John E. Watkins

Robert C. Shearman

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Bruneau, Arthur H.; Watkins, John E.; and Shearman, Robert C., "EC81-1235 Turfgrass Disease Damage Prevention and Control ; A Common Sense Approach" (1981). Historical Materials from University of Nebraska-Lincoln Extension. 4590. http://digitalcommons.unl.edu/extensionhist/4590

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Turfgrass Disease Damage Prevention and Control [ A Common Sense ApQroach

:-~-·. ·.·..... : ~ Integrated Pest Management ...... o - INSTITUTE OF AGRICULTURE AND NATURAL RESOURCES Arthur H. Bruneau, Extension IPM Turf Specialist John E. Watkins, Extension Plant Pathologist Robert C. Shearman, Extension Turfgrass Specialist Contents Introduction ...... 1 Pest Management Practices ...... 1 Spot (Melting Out) ...... 4 Blight ...... 6 Rust ...... 8 Dollar Spot ...... 10 Stripe Smut (Leaf Smut) ...... 12 Pythium Blight (Cottony Blight, Grease Spot) ...... 14 Brown Patch ...... 16 Septaria Leaf Spot and Tip Blight ...... 18 Pink Mold (Fusarium Patch) ...... 20 Gray Snow Mold (Typhula Blight) ...... 22 Powdery Mildew ...... 24 Fairy Ring ...... 26 Occurrence of Diseases ...... 28 Revised August 1981 , UXXl INTRODUCTION PEST MANAGEMENT PRACTICES Turf diseases result from the combina­ Mowing tion of a susceptible host, virulent Mowing height and frequency are im­ pathogen, and environmental conditions portant for maintenance of quality turf favorable for disease development. and must be adjusted to the time of year Cultural practices also influence disease and turfgrass growth rate. For example, severity. Some diseases become much mow Kentucky bluegrass and fine fes­ more serious when turf is poorly main­ cues at 1.5 to 2.0 inches (3 .8-5.1 em) in tained. and fall and at 2.5 to 3.0 inches The interaction of environment and (6 .4-7.6 em) in the . Higher cut­ cultural practices to disease occurrence ting height in summer maintains more and development is not completely vegetation which helps reduce understood. Management practices that temperatures and minimize turfgrass favor vigorous, but not lush, turfgrass high temperature stress. Change the growth and are detrimental to pathogen mowing h~ight gradually during the tran­ development, result in less turfgrass in­ sition between seasons. As a general rule, jury. The IPM Guide is designed to help remove no more than 30 to 40% of the leaf turf managers identify common diseases, area with any mowing. Avoid scalping or to better understand environmental and mowing lower than the recommended cultural aspects influencing disease de­ height of cut. velopment and to promote IPM approaches to disease prevention and Fertilization control. Careful management is an effec­ Fertilize to meet the nutritional needs tive disease deterrent. of the turf, but avoid excessive growth.

1 Slow-release nitrogen carriers or fertiliz­ rapidly when grass blades are con­ ers containing a combination of fast-and tinuously moist for six or more hours. slow-release carriers are preferred since they are less likely to promote lush, Soil Cultivation succulent growth. Fertilizer application Heavy compact readily when traf­ timing also influences disease develop­ ficked . Soil compaction impedes turfgrass ment. Late-season fertilizer applications growth and development by limiting air, timed with the last mowing of the season water, and nutrient penetration. Turfs are preferred to early spring (March­ growing in compacted soils are more April) application. Avoid early spring ap­ prone to disease and environmental plications with fast-release nitrogen car­ stress. Soil cultivation (coring or aerifica­ riers. tion) practiced when turf is actively grow­ ing, helps alleviate compaction and im­ Irrigation proves turfgrass root penetration. This The amount of water needed varies allows the turf to better withstand high with turfgrass and cultivar, sea­ temperature and drought stress. son, location, climate, cultural intensity and use. Water deeply but infrequently to Thatch encourage the plant to develop a deep Practices that promote vigorous turf root system. Light, frequent watering en­ may encourage thatch development. Soil courages a shallow root system and aeration or coring can be used to mini­ weakened turf that is more prone to in­ mize thatch accumulation and modify it fection and stress. for better turfgrass growth. Dethatch Early morning is the best for watering. turfs when thatch accumulation exceeds Avoid evening and night watering. Leaf one-half inch (1 .3 em). A combination of spot, dollar spot, rust, stripe smut, and aerification and power raking is prefer­ Fusarium blight are diseases that develop red. Turfs should be dethatched when 2 actively growing. Light, repeated power of at least three improved Kentucky raking is preferred when ·excessive 1.5 bluegrass cultivars is suggested for best inch (3.8 em) or greater, thatch is present. performance when a Kentucky bluegrass is desired. Genetic Resistance Adapted turfgrass species and cultivars are better able to tolerate stress and are Fungicides can be divided into two less likely to be damaged by disease than groups: protectants and eradicants. Pro­ nonadapted ones. Some species and cul­ tectants are applied before the disease de­ tivars exhibit tolerance to different dis­ velops. To be most effective, protectant eases. This response can be influenced by fungicides must be persistent or be main­ environment and cultural practices. For tained by repeated applications. Eradi­ these reasons it is sometimes difficult to cant fungicides kill existing pathogens on group turfgrass cultivars into highly re­ contact, prevent further growth of the sistant, moderately resistant, or suscepti­ pathogen and restrict its development. ble categories. Fungicides are most effective when ap­ Base turfgrass selection on cultivar plied as preventatives before serious dis­ trials conducted over several years and ease development occurs. under conditions similar to those where Turf managers must be familiar with turf will be grown. University recom­ the disease to insure proper approaches mendations are largely based on such re­ for its prevention and control. This pub­ gional trials. lication will help turf managers meet this A blend of improved adapted grasses need. should be used rather than a single culti­ var. This helps insure good performance over a wide range of conditions. A blend

3 LEAF SPOT (Melting-Out)

Cause: Helminthosporium spp. Hosts: Kentucky bluegrass, coarse and fine fescue, bentgrass, perennial ryegrass, Bermudagrass, zoysiagrass. Area Affected: All areas where host grasses are grown. Occurrence: Crown and Root Rot------~~~~------

April Sept. Nov.

Leaf Spot Melting-Out or Root Rot

4 Symptoms Factors Favoring Leaf Spot During cool wet months of spring and Leaf spot fungi are most active during fall , infected show small reddish­ cool, moist weather. The fungi survive in brown , purple, purplis h-brown or thatch. Turf exhibiting lush, succulent straw-colored spots surrounded b y a ?rowth is particularly prone to leaf spot dark border. Lesions increase, becoming InJury. Evening watering provides sus­ round to oval with the center gradually tained moisture on the leaf surface which fading to light brown or straw color. Le­ is sufficient for germination and sions may become so numerous on . Continual mowing at low blades of susceptible cultivars that the heights may stress the turf and enhance turf appears brown. Severe leaf spot infection of turfgrass crowns and roots. leads to melting-out which is charac­ Heavy activity on wet turf spreads the terized by leaf sheath infection causing pathogen. blades to tum yellow and slough. Sheath Pest Management lesions are dark brown and lack the tan center and regular outline of spots that 1. Use leaf spot resistant cultivars. occur on blades. Melting-out areas will 2. Raise the mowing height to 2.5 to first appear yellow, resembling nitrogen 3.0 inches (6.4-7 .6 em) in summer. defi ciency or iron chlorosis, and then 3. Aerate and power rake in spring, may turn brown or die under stress. Leaf fall, or both to improve soil, en­ spot and melting-out is less evident in hance roots and remove thatch. summer. The causes a reddish­ 4. A void heavy early spring fertiliza­ brown rotting of the crowns, roots and tion with soluble fertilizers. rhizomes during this period. 5. Water infrequently but deeply. 6. Apply a registered when leaf spot is active in spring and fall. 7. Keep mower blades sharp. 5 FUSARIUM BLIGHT

Cause: Fusarium roseum and F. tricinctum Hosts: Annual and Kentucky bluegrass, fine fescue, bentgrass, perennial rye grass. Areas Affected: Home , golf course fairways and tees, park and athletic turfs.

Occurrence:

May Jul y Oct.

"Frog-eye" PaHern

6 Symptoms Pest Management Fusari urn blight occurs as a foliage 1. Avoid heavy summer fertilization. blight and as a crown and root rot. Af­ 2. Use slow-release fertilizers. fected bluegrass stands show scattered 3. Water deeply and infrequently. patches of blue-green, wilted turf which Prevent drought stress. rapidly changes to a dull, reddish­ 4. Daily syringing in July and August brown. Blighted areas are sunken and at midday. Syringing cools the turf. roughly circular, crescent or serpentine­ 5. Power rake to remove thatch. shaped. Severely blighted turf areas ap­ 6. Aerate in spring, fall, or both to im­ pear pock-marked. Many patches contain prove rooting and penetration. centrally located tufts of healthy turf pro­ 7. Use blends of heat and drought tol­ ducing the "frog-eye" symptom. Large erant, improved cultivars. areas of turf may be destroyed. Lesions 8. Increase mowing height of blue­ on individual blades are straw-colored grass in summer to 2.5 to 3.0 inches and appear in alternating green and (6.4-7.6 em) where feasible. Even white bands. slight increases of mowing heights on golf fairways can be beneficial in Factors Favoring Fusarium Blight minimizing stress. Fusarium may infect any bluegrass 9. If fungicide is necessary, drench the lawn but primarily occurs on 3- to 4- fungicide into the soil with 1/ 2 inch year-old or older turfs. Heat and water (1.3 em) of water immediately after stress accentuate disease symptoms. Sus­ treatment. ceptible cultivars, excessive thatch, con­ tinuous low mowing, soil compaction and improper fertilization contribute to severity. 7 RUST

Cause: Puccinia spp. Hosts: Annual and Kentucky bluegrass, perennial ryegrass, Bermudagrass, zoysiagrass, fine fescue. Areas Affected: Seedlings and nutritionally stressed turfs.

Occurrence:

July Sept. Nov.

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8 Symptoms growth has slowed. Severe rusting indi­ Rust infected turf becomes reddish­ cates inadequate fertilization. Infrequent brown or yellow in appearance. Rust be­ mowing intervals results in a buildup of gins as yellow orange flecks on indi­ rust pustules on leaves and stems. vidual grass blades and stems that de­ velop into orange or brick red pustules. Pest Management within the powdery pustules eas­ 1. Use rust resistant cultivars. Avoid ily rub off when touched. A continuous, Merion Kentucky bluegrass which heavy rusting causes leaf blades to yel­ is very susceptible. low, withe1 and die. Susceptible turfs 2. Maintain proper mowing frequency may be substantially thinned. Clouds of and remove clippings from infected orange dust (rust spores) can ·quickly dis­ turfs. color shoes, mowers, or clothing. In­ 3. Use a balanced fertilizer program. fected turf may be weakened and become 4. Water early in the day so turf will more subject to -kill and other pest dry quickly. Avoid evening water­ attacks. ing. 5 . When needed, spray the turf at 7 to Factors Favoring Rust 14 day intervals with a suggested Rust usually occurs in late summer fungicide. following hot, dry periods when grass

9 DOLLAR SPOT

Cause: Sclerotinia homeocarpa Hosts: Ann ual and Kentucky bluegrass, bentgrass, perennial ryegrass, fine fescue, zoysiagrass, Bermudagrass. Areas Affected: Home lawns, parks, golf course turfs.

Occurrence:

May July Oct.

Bluegrass Bentgrass

10 favor the disease. Clippings may serve as Symptoms a means of infection when the disease is On closely cut turf, the disease appears active_. Traffic may spread the pathogen as small circular patches of bleached espeCially when the turf is wet. The dol­ grass ranging in size from that of a dime lar spot causing fungus overwinters in up to a silver dollar. These patches may thatch. merge and become larger as disease ac­ tivity increases. On lawn turfs indi­ Pest Management vidual spots are larger and less distinct 1. Use resistant cultivars. than on bentgrass. Affected lawns show 2. Fertilize to meet the nutritional irregular, straw-colored patches of dead needs of the turf. grass resembling melting-out or drought 3. Water infrequently but deeply and damage. Infected leaf blades have bleach at a time when the grass blades will to tan lesions that span the width of the dry rapidly. blade and are bordered by reddish­ 4. Syri~ge the turf in the morning to brown margins. A white cobweb-like mm1m1ze duration and extent of may be observed on the foliage dew formed. when dew is present. 5. Remove and dispose of clippings of infected turfs. Factors Favoring Dollar Spot 6. Power rake to reduce thatch The presence of dollar spot may signal buildup. a nutnhonally deficient turf. Warm days 7. Apply registered fungicides at first and cool mghts that result in heavy dews appearance of disease where dollar spot has been a problem.

11 STRIPE SMUT (LEAF SMUT)

Cause: Ustilago striiformis Hosts: Kentucky bluegrass, bentgrass, perennial ryegrass. Areas Affected: All areas where the host grasses are grown.

Occurrence:

April June Sept. Nov.

Black Smut Sori

12 Symptoms ity ceases in hot dry weather, and the cycle is repeated with the onset of fall. Infection occurs on single plants or Use of s usceptible cultivars, evening patches varying in size from a few inches watering and excessive nitrogen favor to a foot or more in diameter. disease development. Once the plant is Infected plants appear chlorotic and infected, it remains infected until it dies. stunted. Symptoms may be mistaken for early leaf spot activity. Individual blades Pest Management develop dull, gray stripes (pencil lead 1. Use stripe smut resistant cultivars. color and size) running parallel to the Avoid highly susceptible cultivars veins and plants appear erect with stiff such as Merion and Windsor Ken­ leaves. The gray stripes eventually turn tucky bluegrass. black rupturing the foliage to release 2. Water early in the day so turf will numerous sooty spores. Release of the dry quickly. Avoid light, frequent spores causes the leaves to twist and irrigation or evening watering. shred from the tip down resultmg in 3. Meet the nutritional needs of the death of the plants. turf without overfertilizing. Fa~tors Favoring Smut 4. Certain systemic fungicides can be used to control smut. Begin treat­ Stripe smut is most active during cool, ment in the fall where stripe smut wet periods in the spring and fall. Achv- has been a problem.

13

tl PYTHIUM BLIGHT (COTTONY BLIGHT, GREASE SPOT)

Cause: Pythium spp. Hosts: Bentgrass, perennial ryegrass, annual and Kentucky bluegrass, course and fine fescue. Areas Affected: Golf greens, tees and fairways.

Occurrence:

May July Sept.

Cottony Blight Grease Spot

14 Symptoms The disease may occur to a limited extent Pythium blight appears in a turf area as under cooler conditions . Turfs that are small (6 in., 15 .2 em) brown, sunken heavily trafficked and poorly drained are spots often following drainage or mow­ especially prone to injury. ing patterns. Infected grass feels greasy Pest Management to the touch ·and has a fishy odor. The 1. Av.oid .overwatering, light frequent spots rapidly increase in size and in­ Irngatwn and evening watering. fected areas become matted. Leaves first Water deeply and infrequently . appear water-soaked then straw-colored. 2. Insure good surface and subsurface A greasy, water-soaked border of black­ drainage. ened leaves and cottony fungus 3. Aerify or core to eliminate compac­ m ycelium is usually present at the mar­ tion, Improve water penetration gin of the spot while dew is present. Due and enhance root development. to rapid development of this disease, 4. Fertilize to meet nutritional needs of large areas of turf can be killed in a few the turf but avoid overstimulation. hours. 5. Apply a ,registered fungicide when Factors Favoring Pythium Blight hot, humid weather is forecast and The Pythium fungus survives in thatch Pythium blight has been a problem. and in the soil. It becomes active when 6. Wash mowing equipment to day temperatures are above 85°F (29.4°C), minimize spread. night temperatures

15 BROWN PATCH

Cause: Rhizoctonia so /an i Hosts: Bentgrass, annual and Kentucky bluegrass, perennial ryegrass, coarse and fine fescue. Areas Affected: Golf course greens. Limited development on home lawns.

Occurrence:

Smoke ring July September

Brown Patch

16 Symptoms mowing increases susceptibility of cul­ Brown patch appears in circular brown tivars to brown patch. patches that may be several feet in Pest Management diameter. Leaves first appear dark green and water-soaked, then wilt and turn 1. Avoid heavy, early s pring and light brown. Dead leaves remain upright. summer fertilization. A dark, grayish-black ring (smoke ring) 2. Use slow-release fertilizers. of wilted grass often is present at the 3. Promptly remove and dispose of perimeter of the diseased areas in early clippings on infected areas or w hen morning. This area disappears as the conditions are conducive to disease grass is stressed and dies. Symptoms on development. bluegrass may resemble the "frog eye" 4. Relocate landscape plantings to pattern caused by Fusarium blight. allow for better air movement across golf course greens. Factors Favoring Brown Patch 5. Wat.er infrequently but deeply in Brown patch occurs on dense, closely the early morning. cut turfs in ho t (a bove 85°F, 29.4°C), 6. Use a preventive fungicide program humid weather when night temperatures on bentgrass greens where brown remain above 60°F (lS.6°C) and leaf sur­ patch is a persistent problem. faces remain wet for 6 to 8 hours. High 7. Apply a registered fungicide at first levels of nitrogen, low levels of phos­ evidence of disease where brown phorous or potassium may contribute to patch has been a problem. increased dis ease severity. The use of a 8. Avoid con tinuous low mow ing dull mower blade frays the edges of cut coupled with high nitrogen fertili­ blades and serves as a point of entrance zation of Kentucky bluegrass turfs. of the fungus into the leaf. Frequent low 17 SEPTORIA LEAF SPOT AND TIP BLIGHT

Cause: Septaria spp. H osts: Annual and Kentucky bluegrass, fine fescue, bentgrass, Bermuda­ grass. Areas Affected: Home lawns, golf course fairways, parks, athletic turfs.

Occurrence:

April July Sept. Nov.

Black Fungus Pycnidia

18 evening watering enhance spread and Symptoms severity. Infected lawns resemble injury from a dull mower without having frayed leaf Pest Management tips. Leaf lesions are yellow to light tan 1. Use resistant cultivars. Avoid sus­ with black dots (pycnidia) embedded ceptible cultivars like Merion and within the lesion. Yellowing occurs from Delta Kentucky bluegrass. the leaf tip downward. 2. Remove dew b y syringing in early Factors Favoring Septoria Leaf Spot and morning. 3. Water in early morning. Tip Blight 4. Avoid overfertilization and promo­ Septaria is most noticeable during tion of lush succulent growth. cool, wet weather and is of minor im­ 5. Apply a fungicide during cool, wet portance in summer. Heavy dews and weather where Septaria leafspot has been a problem.

19 PINK SNOW MOLD (FUSARIUM PATCH)

Cause: Fusarium nivale Hosts: Annual and Kentucky bluegrass, bentgrass, perennial ryegrass, fine fescue. Areas Affected: Golf course greens. Limited development on home lawns.

Occurrence:

Oct. April May

Pink Snow Mold

20 Symptoms serious on areas where air movement and soil drainage are poor and grass stays wet Irregular to circular bleached-tan to for long periods. Lush, tall growth in late reddish-brown patches, approximately 2 fall , and plant injury due to activity on inches (5.1 tm) to 2 feet (61 em) in frosted turf enhance damage. diameter are typical of pink snow mold. These may occur in fall , winter or spring Pest Management whenever conditions are favorable. The 1. Avoid overstimulation of the turf in margins of affected turf may appear light late fall . Apply a slow-release fer­ pink and are most notic~able at the ad­ tilizer at the time of last mowing. vancing edge of melting snow. Wh_en 2. Use resistant cultivars. wet, diseased areas may -be covered w1th 3. Reduce snow buildup by proper a dense, slimy mat of•.white fungal placement of barriers, snow fences, mycelium that later turns pink. or landscape plantings where snow Factors Favoring Pink Snow Mold mold ha~ been a serious problem. (Precautions should be taken to Disease development can occur any­ prevent winter desiccation.) time the temperature drops below 60oF 4. Improve drainage. (15 .6°C) . The greatest pink snow mold 5. Apply preventive fungicide treat­ activity occurs when snow falls o~ unfro­ ment in late fall and during mid­ zen ground. Pink snow mold IS most winter thaws where snow mold has been a problem.

21 GRAY SNOW MOLD (Typhula Blight)

Cause: Typhula spp. Hosts: Creeping ben tgrass, annual and Kentucky bluegrass, perenn ial rye­ grass, coarse and fi ne fescue. Areas Affected: Golf course turfs, home lawns.

Occurrence:

O ct. Nov. April May

22 Tall, lush growth; snow compaction Symptoms and injury to frosted turf due to traffi~ Pale yellow to straw-colored patches of increase gray snow mold damage. Turf affected turf become visible in the areas surrounded by landscape plantings spring. These areas are roughly circular are prone to gray snow mold. Gray snow and range from several inches to several mold development stops in the absence feet in diameter. Several circles may of a snow cover. merge to form large irregular areas. Dis­ eased areas are often covered with a Pest Management bluish-gray fungal mycelium when the 1. Use tolerant cultivars. tud is wet. As the turf dries the 2. Avoid excessive fertilization that mycelium becomes a silvery crust-like stimulates lush growth in the fall . mat. Close examination of infected turf 3. Avoid snow accumulation by pro­ reveals the presence of sand-grain sized, per placement of barriers or snow orange to brown fungal sclerotia. The fences. Where snow mold has been presence of these sclerotia distinguish a serious problem precautions this disease from pink snow mold. should be taken to prevent winter Factors Favoring Gray Snow Mold desiccation. 4. Apply a registered fungicide in late Disease development occurs when the fall and during midwinter thaws ground is unfrozen, soil moisture is where snow mold has been a prob­ plentiful and the temperature is between lem. 32 to.40° F (0-4.4° C) . Initial development 5. Direct traffic patterns away from requ1res the absence of light which is potentially diseased areas. brought about by snow cover in most in­ 6. Mow frequently and maintain grass stances. at the suggested height of cut as long as it remains green in the fall. 23 POWDERY MILDEW

Cause: Erysiphe graminis Hosts: Kentucky bluegrass. Areas Affected: Shady locations.

Occurrence:

May Aug. November ( ,_. -~. :/f r r \. \~ I •' / Powdery Mildew

24 Symptoms is not required for infection. The upper leaf surface of infected Pest Management plants exhibits a white, powdery growth that gives the leaf an appearance of hav­ 1. Use improved cultivars. Plant shade ing been dusted with flour or lime. In­ adapted mixtures or blends in fected leaves may yellow, wither and die. shaded sites. New plantings may be severely thinned. 2. Selectively prune trees and shrubs to enhance light penetration and air Factors Favoring Mildew circulation. Mildew is most serious on new seedl­ 3. Avoid screening air movement over ings or in shady locations where light the turf. intensity and air movement are re­ 4. Avoid lush growth but fertilize to stricted. The disease overwinters in meet the nutritional needs of the thatch and in infected plants. The spores turf. are spread by air currents and become 5. Apply a registered fungicide to turf active when the air temperature ap­ areas with a history of mildew. proaches 65°F (18.3° C) and humidity is 6. Avoid mowing turf too short. high. Unlike other pathogens, free water 7. Water infrequently but deeply.

25 FAIRY RING

Cause: Soil-inhabiting mushroom-forming fungi. Hosts: All grasses. Areas Affected: All areas where turf is grown.

Occurrence:

Aprif July Nov.

Mushrooms Fairy Ring

26 Symptoms possible. However, certain practices can Circles or arcs of a narrow band (3-8 be employed to reduce turf damage. in., 7.6-20 em) of dark green, fast grow­ 1. Remove tree roots, boards and other ing grass are typical symptoms of fairy organic debris before seeding or ring. Rings may be several feet in sodding. diameter. A zone of thin, weak, or dead 2. Mow mushrooms before they open. turf is often observed within the dark 3. Fertilize to meet nutritional needs of green band itself. Mushrooms may for~ the turf. in the band when cool, wet weather oc­ 4. Remove soil cores or in some man­ curs. ner open the soil within the ring to allow better water and nutrient Factors Favoring Fairy Ring penetration. Use wetting agents to Fairy ring will occur whenever suffi­ reduce surface tension and improve cient soil organic matter is present to water percolation. Inject water into s upport fungal growth. Rotting tree the ripg with a tree root feeder. parts, lumber and excessive thatch are 5. Power rake to reduce thatch ac­ ideal sites for fairy ring development. cumulations when they exceed Fairy ring will persist long after any visi­ one-half inch (1.3 em). ble evidence of organic matter is gone. 6. Remove all soil from within one foot (30 em) to either side of the ring and Pest Management at least one foot deep, fumigate and Elimination of fairy ring is nearly im- replace with clean soil, if practical.

27 Occurrence Of Diseases

Disease Jan. Feb. March

Leaf Spot

Strj pe Smut

Fairy Ring

Dollar Spot

Powdery Mildew Septoria Leaf Spot

Fusarium Blight

Brown Patch

Rust

Pythium Blight Gray Snow Mold

Pink Snow Mold

28