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http://www.caes.uga.edu/extension/

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Learning ObjectivesLearning Objectives

•• InsectInsect--related injury in the lawnrelated injury in the lawn•• Common insects affecting turfgrass in Common insects affecting turfgrass in

GeorgiaGeorgia•• Preventing or controlling insect Preventing or controlling insect

damage to turfgrassdamage to turfgrass•• Symptoms of turfgrass diseasesSymptoms of turfgrass diseases•• Preventing or Preventing or controlllingcontrollling turfgrass turfgrass

diseasesdiseases

Insects and Insects and Diseases of TurfDiseases of Turf

Dr. Kris Braman Dr. Kris Braman Dr. Alfredo MartinezDr. Alfredo Martinez

Turf insect damageTurf insect damage

White grub damageWhite grub damage

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Insect Problems in TurfInsect Problems in Turf

•• Soil InhabitantsSoil Inhabitants•• Thatch inhabitantsThatch inhabitants

Steps to Managing Turf PestsSteps to Managing Turf Pests

•• PreventionPrevention•• Thatch removalThatch removal•• Early detectionEarly detection

Sampling: Sweep netSampling: Sweep net

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Sampling: FloatationSampling: Floatation

Sampling: IrritationSampling: Irritation

Monitor pest populationsMonitor pest populations

Fall armyworm damageFall armyworm damage

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Correct Pest IdentificationCorrect Pest Identification

chemical damage, not insectchemical damage, not insect……

Proper Selection of Control MaterialsProper Selection of Control Materials

Correct Application MethodsCorrect Application Methods

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When Applying Insecticides When Applying Insecticides Consider:Consider:

•• DistributionDistribution•• Irrigation requirementsIrrigation requirements•• Insecticide formulationInsecticide formulation•• Timing of insecticide applicationTiming of insecticide application•• Target zone of the insecticide Target zone of the insecticide

applicationapplication

PESTSPESTS

Identification, Life Cycle and Identification, Life Cycle and DiagnosisDiagnosis

Ground PearlsGround Pearls

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Mole CricketsMole Crickets

White GrubsWhite Grubs

BillbugsBillbugs

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Leaf, Stem and Thatch Leaf, Stem and Thatch Inhabiting InsectsInhabiting Insects

SpittlebugsSpittlebugs

ChinchbugsChinchbugs

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Sod WebwormsSod Webworms

ArmywormsArmyworms

CutwormsCutworms

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NonNon--harmful Turf Inhabitantsharmful Turf Inhabitants

Cicada Killer WaspCicada Killer Wasp

EarwigsEarwigs

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Millipedes & CentipedesMillipedes & Centipedes

Sowbugs & PillbugsSowbugs & Pillbugs

Questions?Questions?

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Turfgrass Turfgrass DiseasesDiseases

••Adds beauty and value to any propertyAdds beauty and value to any property••Versatile and functional plant in the landscapeVersatile and functional plant in the landscape••Most effective plant cover Most effective plant cover ••Reduces soil erosion and surface water runReduces soil erosion and surface water run--offoff••Recharges ground waterRecharges ground water••Reduces heat (30Reduces heat (30ººF below that of asphalt area)F below that of asphalt area)••Average lawn area has a cooling effect equals 8 ton Average lawn area has a cooling effect equals 8 ton of air conditioning of air conditioning ••Absorbs dust and other pollutantsAbsorbs dust and other pollutants••Produces oxygenProduces oxygen

TurfgrassTurfgrass

•Due to diverse environmental conditions and clientele choices in GA there are a wide variety of turfgrass species grown

•Variety of turfgrass pathogens flourish

•In 2000, disease losses and control costs account for over $200 million

DiseasesDiseases

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Most turfgrass diseases canMost turfgrass diseases canbe avoided using proper management be avoided using proper management

strategies strategies

•• Reduction in expensesReduction in expenses•• Save water resourcesSave water resources•• Reduce pesticide useReduce pesticide use•• Reduce negative impact on the Reduce negative impact on the

environmentenvironment

Management practices to reduce Management practices to reduce turf disease problemsturf disease problems

•• Prepare the soil properlyPrepare the soil properlyTake soil samples, remove debris, ensure pTake soil samples, remove debris, ensure proper roper water drainagewater drainage

•• Plant locally adapted turf speciesPlant locally adapted turf species

•• Purchase high quality diseasePurchase high quality disease--free seed, sod or free seed, sod or sprigssprigs

•• Follow proper irrigation practicesFollow proper irrigation practices

•• Apply fertilizer according to soil analysis Apply fertilizer according to soil analysis

•• Mow at recommended heightMow at recommended height

•• Remove excessive thatchRemove excessive thatch

•• Allow for adequate light and air movementAllow for adequate light and air movement

•• Follow recommended disease control Follow recommended disease control practicespractices

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Specific diseasesSpecific diseases

•• Caused by the fungus Caused by the fungus Rhizoctonia Rhizoctonia solanisolani

•• Disease symptoms are Disease symptoms are circular patterns of dead circular patterns of dead grass grass

•• Turf turns brown and Turf turns brown and grass blades rot offgrass blades rot off Most common inMost common in

St. Augustine, St. Augustine, ZosysiagrassZosysiagrassBentgrassBentgrassRyegrassRyegrassCentipedeCentipedeBermudaBermuda

Brown PatchBrown Patch

••Brown Patch can spread in Brown Patch can spread in an area from 1an area from 1--50'.50'.

••New leaves may emerge in New leaves may emerge in the center of the circular the center of the circular patch giving the diseased patch giving the diseased areas a doughnutareas a doughnut--shaped shaped

appearance.appearance.

BP Accounts for 65% of UGA BP Accounts for 65% of UGA

Disease Clinic Turf SamplesDisease Clinic Turf Samples

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Patches merge to affectPatches merge to affectlarger areaslarger areasOccasionally circular Occasionally circular patterns arenpatterns aren’’t evidentt evident

••Heavy/recent infectionsHeavy/recent infectionsproduce foul smellproduce foul smell

••Leaves/runnersLeaves/runnerspull out easilypull out easily

Infection requirementsInfection requirements

----Brown Patch occurs Brown Patch occurs from late Spring through from late Spring through Early Fall (temperatures Early Fall (temperatures between 65between 65--85 85 ºº FF) )

----High humidity High humidity contributes to rapid contributes to rapid disease spreaddisease spread

----High NitrogenHigh Nitrogen

ControlControl1) Scout: Early detection is key for disease prevention/control1) Scout: Early detection is key for disease prevention/control

Look for abnormal appearance/spots on turfLook for abnormal appearance/spots on turf

Look closely for early symptoms/ signs of the diseaseLook closely for early symptoms/ signs of the disease

Note weather patternsNote weather patterns

Keep notes of site changesKeep notes of site changes

History of problems in the site History of problems in the site

2) Avoid excessive Nitrogen fertilization 2) Avoid excessive Nitrogen fertilization

Maintain adequate Nitrogen levels)Maintain adequate Nitrogen levels)

3) Water Timely and Deeply (After midnight/before 11 AM)3) Water Timely and Deeply (After midnight/before 11 AM)

55--6 inches6 inches

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4) Avoid frequent light irrigation to reduce humidity4) Avoid frequent light irrigation to reduce humidity

Allow time during the day to allow plant canopy to dryAllow time during the day to allow plant canopy to dry

5) Increase air circulation5) Increase air circulation

Shrub and tree barriers contribute to shade Shrub and tree barriers contribute to shade

and lack of air circulationand lack of air circulation

6) Reduce thatch (no more than 1 inch thick)6) Reduce thatch (no more than 1 inch thick)

Excessive thatch: restricts water and air movementExcessive thatch: restricts water and air movement

Promote shallow root growthPromote shallow root growth

Promotes an ideal environment for pathogensPromotes an ideal environment for pathogens

Chemical control for Brown PatchChemical control for Brown Patch

Among others:Among others:Azoxystrobin (Heritage 50 WG)Azoxystrobin (Heritage 50 WG)Propiconazole (Banner)Propiconazole (Banner)TriadimefonTriadimefon ((BayletonBayleton))IpropidioneIpropidione ((ChipcoChipco 26091)26091)TrifloxystrobinTrifloxystrobin (Compass)(Compass)ThiophanateThiophanate Methyl (ClearyMethyl (Cleary’’s)s)

There are many fungicides available, become familiarThere are many fungicides available, become familiarwith the with the ““Georgia Pest Management HandbookGeorgia Pest Management Handbook

Dollar SpotDollar Spot

•• Causal agent is Causal agent is SclerotiniaSclerotiniahomoeocarpahomoeocarpa

•• White patches up to 2 White patches up to 2 inches in diameterinches in diameter

•• All warm and cool All warm and cool season turfgrasses are season turfgrasses are susceptible.susceptible.

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••Infection requirementsInfection requirements

5050ooF F -- 8585ooF (Early Spring F (Early Spring Late Fall)Late Fall)

Cool nights/Warm daysCool nights/Warm days

>10 hrs leaf >10 hrs leaf wetness/daywetness/day

Dry SoilsDry Soils

Low Nitrogen promotes Low Nitrogen promotes growth of the fungusgrowth of the fungus

Control for dollar spotControl for dollar spot•• Maintain adequate Nitrogen levels (Low Maintain adequate Nitrogen levels (Low

Nitrogen)Nitrogen)

•• Avoid drought stress (dry soils promote Avoid drought stress (dry soils promote the disease) the disease)

•• Water deeply (Water deeply (…….holding the hose for a .holding the hose for a few minutes in not watering few minutes in not watering appropriately)appropriately)

••Avoid extended moisture on leaves /remove Avoid extended moisture on leaves /remove dew in morningdew in morning

••Increase air circulationIncrease air circulation

••Mow at recommended heightMow at recommended height

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•• ChlorothalonilChlorothalonil•• ThiophanateThiophanate--methylmethyl•• IprodioneIprodione, , vinclozolinvinclozolin•• TriadimefonTriadimefon, myclobutanil, , myclobutanil, fenarimolfenarimol, ,

propiconazolepropiconazole

Chemical control for Dollar SpotChemical control for Dollar Spot

Use the Use the ““Georgia Pest Management HandbookGeorgia Pest Management Handbookas referenceas reference

Pythium blightPythium blight

•• Causal agent Causal agent Pythium Pythium spp spp

•• Disease is characterized Disease is characterized small, irregular watersmall, irregular water--soaked areas. Brown, soaked areas. Brown, orange/bronze, light/tan orange/bronze, light/tan

•• Numerous spots, merge Numerous spots, merge in wettest areasin wettest areas

••Turf dies rapidly, Turf dies rapidly, collapses and appear collapses and appear mattedmatted

••Infected tissue feels Infected tissue feels oily to touchoily to touch

••If high humidity If high humidity present fluffy, cottony present fluffy, cottony white mycelium present white mycelium present (can be seen early in (can be seen early in the morning)the morning)

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Control measures for Control measures for Pythium Blight Pythium Blight

••Water management is essentialWater management is essential

••Correct over watering/drainage problemsCorrect over watering/drainage problems

••Avoid pockets of excessive humidityAvoid pockets of excessive humidity

••Use treated seed when ReUse treated seed when Re--seedingseeding

••Do not over fertilize with NitrogenDo not over fertilize with Nitrogen

••Promote light and air penetrationPromote light and air penetration

Chemical control for Pythium Chemical control for Pythium

Use the Use the ““Georgia Pest Management HandbookGeorgia Pest Management Handbookas referenceas reference

Fairy ringFairy ring

•• Different Different BasidiomycetousBasidiomycetous fungifungi•• Mushroom (Mushroom (basidiocarpbasidiocarp) producing ) producing

fungifungi•• In Nature, woodIn Nature, wood--rooting rooting •• Circular or semiCircular or semi--circular bandcircular band

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••Affects all turf typesAffects all turf types••Most common and damaging on Most common and damaging on Centipede, Zoysiagrass and St. Centipede, Zoysiagrass and St. Augustinegrass.Augustinegrass.••Most on sandy soils of low fertilityMost on sandy soils of low fertility••Also favored by heavy thatchAlso favored by heavy thatch••Sometimes associated with buried Sometimes associated with buried debrisdebris

Management for fairy ringManagement for fairy ring

•• Spike or aerate affected areasSpike or aerate affected areas•• If necessary for aesthetic purposes If necessary for aesthetic purposes

Water heavilyWater heavilyExtra fertilizer where appropriateExtra fertilizer where appropriate

•• Soil replacement Soil replacement •• Fungicide treatment Fungicide treatment

Fungicides for fairy ring controlFungicides for fairy ring control

••FlutolanylFlutolanylSeveral others with marginal effectSeveral others with marginal effect

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‘‘FadingFading’’ and and ‘‘melting outmelting out’’CurvulariaCurvularia and and HelminthosporiumHelminthosporium sp.sp.

•• Both fungi are common thatch and Both fungi are common thatch and soil inhabitantssoil inhabitants

•• Can cause disease when K is low Can cause disease when K is low and drought stress occursand drought stress occurs

•• Bermudagrass, Bermudagrass, zoysiagrasszoysiagrass, , centipedegrasscentipedegrass

•• Common during the past 2 to 3 Common during the past 2 to 3 yearsyears

Curvularia: Curvularia: large overall declinelarge overall decline

Helminthosporium: Helminthosporium: light colored spotslight colored spots

dark edgesdark edges

High Temperature High Temperature Drought stressDrought stressLow aerationLow aeration

Low light intensityLow light intensityExcessive NitrogenExcessive Nitrogen

Factors that promote disease incidenceFactors that promote disease incidence

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Management for Curvularia and Management for Curvularia and Helminthosporium diseasesHelminthosporium diseases

•• Prevent drought stress to the turfPrevent drought stress to the turf•• Water properlyWater properly•• Soil test/insure adequate KSoil test/insure adequate K•• Address excessive thatchAddress excessive thatch•• Protectant fungicides availableProtectant fungicides available•• Consult the GA Pest Management Consult the GA Pest Management

Handbook for proper chemical Handbook for proper chemical controlcontrol

Gray leaf spotGray leaf spotPyricularia griseaPyricularia grisea

••Leaf spot diseaseLeaf spot disease

••StrawStraw--gray lesions gray lesions ••with purple/brown marginswith purple/brown margins

••Rapid spreadRapid spread

••Severely affected leaf blades wither Severely affected leaf blades wither and turn brownand turn brown

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•• Affects St. Augustinegrass and Tall Affects St. Augustinegrass and Tall FescueFescue

•• Favored by high N and excess moistureFavored by high N and excess moisture•• Optimal temps 77 to 86Optimal temps 77 to 86˚̊FF

Gray leaf spotGray leaf spot

Management of gray leaf spotManagement of gray leaf spot

•• ‘‘RoselawnRoselawn’’ and and ‘‘TamlawnTamlawn’’ have some have some resistanceresistance

•• Avoid excessive applications of NAvoid excessive applications of N•• Proper watering practicesProper watering practices•• Reduce thatch when excessiveReduce thatch when excessive•• Reduce shadeReduce shade•• Avoid herbicide use above 85 Avoid herbicide use above 85 ˚̊ FF•• ProtectantProtectant fungicides availablefungicides available

Take-all root rot(Gaeummanomyces graminis)

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Starts as small light brownStarts as small light brown--straw colored death patchesstraw colored death patches

Circular (dead spots, few centimeters toCircular (dead spots, few centimeters to1 or more meters)1 or more meters)

During hot dry weather turf appears bronzeDuring hot dry weather turf appears bronzeto straw in colorto straw in color

SymptomsSymptoms

Many cases St. Augustinegrass turns tan, straw Many cases St. Augustinegrass turns tan, straw coloredcolored

Roots and bases of shootsRoots and bases of shootsappear brown to darkappear brown to dark

Leaves pull out easily from roots and crown, but Leaves pull out easily from roots and crown, but entire plants pull out due to lack of roots (or rotten entire plants pull out due to lack of roots (or rotten roots)roots)

Dark rootsDark roots

Yellow leavesYellow leaves

Thinning of turfThinning of turf

Necrotic areas on crown Necrotic areas on crown

Factors Affecting Factors Affecting Take all root rotTake all root rot

••Disease greatly enhanced in soils with high Disease greatly enhanced in soils with high pH (alkaline soils), low organic content and pH (alkaline soils), low organic content and Sandy soilsSandy soils

••Unbalanced FertilityUnbalanced Fertility

••Excessive ThatchExcessive Thatch

••Poorly drained, irrigated soilsPoorly drained, irrigated soils

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ControlControl••Use of acidifying fertilizersUse of acidifying fertilizers•• (Ammonium sulfate)(Ammonium sulfate)

••Phosphorous/potassium fertilizerPhosphorous/potassium fertilizer

••If liming necessary, use the coarsest ground materialIf liming necessary, use the coarsest ground material

••Maintain adequate Nitrogen levelsMaintain adequate Nitrogen levels

••Water Timely and Deeply (After midnight/before 11 AM)Water Timely and Deeply (After midnight/before 11 AM)

••Allow time during the day to allow plant canopy to dryAllow time during the day to allow plant canopy to dry

••Increase air circulation (Shrub and tree barriers Increase air circulation (Shrub and tree barriers contribute to shade and lack of air circulation)contribute to shade and lack of air circulation)

••Reduce thatch (Excessive thatch restricts water and air Reduce thatch (Excessive thatch restricts water and air movement. Promote shallow root growth. Promotes an movement. Promote shallow root growth. Promotes an ideal environment for pathogens)ideal environment for pathogens)

••Avoid late summer heavy fertilizationAvoid late summer heavy fertilization

••AerificationAerification

••Soil pH 5.5 Soil pH 5.5 -- 6.06.0

••Consult the GA Pest Management Control Handbook for Consult the GA Pest Management Control Handbook for proper chemical controlproper chemical control

Slime mold

Caused by Physarum spp and Fuligo spp. There are other species causing slime mold.

Susceptible Turfgrass: Warm season grasses.

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•Fruiting bodies of these fungi may suddenly appear on grass blades and stems in circular to irregular patches 1-30 inches in diameter.

•Affected patches of grass do not normally die or turn yellow

•Signs of the fungi usually disappear within 1-2 weeks.

•These fungi normally reproduce in the same location each year.

•The fungi are not parasitic, but they may shade the individual grass leaves to the extent that leaves may be weakened byinefficient photosynthesis

Slime mold

Conditions Favoring Disease DevelopmentConditions Favoring Disease Development

Slime molds are favored by cool temperatures and continuoushigh humidity.

An abundance of thatch favors slime molds byproviding food directly in the form of organic matter

•Remove slime mold by mowing.

•Raking and disposing of the slime mold is usually •all that is required.

•The slime mold will go away in warm-dry weatherconditions.

ControlControl

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Centipede declineCentipede decline

•• Disorder not a diseaseDisorder not a disease•• Improper and excessive fertilityImproper and excessive fertility

>Light green color>Light green color>Can not tolerate high N>Can not tolerate high N>Low maintenance>Low maintenance

•• High pHHigh pH

••Heavy thatchHeavy thatch

••Compacted soilsCompacted soils

••NematodesNematodes

Management for centipede Management for centipede declinedecline

•• Soil test Soil test •• Avoid over or improper fertilizationAvoid over or improper fertilization•• Use 3Use 3--11--2 fertilizer ratio2 fertilizer ratio•• Aerate to improve root growthAerate to improve root growth•• Dethatch Dethatch

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Remember: Most of the diseases in turf can Remember: Most of the diseases in turf can be avoided using be avoided using properproper management management strategiesstrategies

••Prepare the soil properlyPrepare the soil properly

••Proper water drainageProper water drainage

••Plant locally adapted turf speciesPlant locally adapted turf species

••Purchase high quality diseasePurchase high quality disease--free free ••seed, sod or sprigsseed, sod or sprigs

••Follow proper irrigation practicesFollow proper irrigation practices

••Apply fertilizer according to soil Apply fertilizer according to soil analysis analysis

••Mow at recommended heightMow at recommended height

••Remove excessive thatchRemove excessive thatch

••Allow for adequate light Allow for adequate light and air movementand air movement

••Follow recommended Follow recommended disease control practicesdisease control practices

Questions?Questions?