oak wilt identification and management
DESCRIPTION
Robert Edmonson, biologist and certified arborist Texas A&M Forest Service, discusses Oak Wilt Identification and Management to the 2013 Master Naturalist, Hill Country Chapter training class.TRANSCRIPT
Oak WiltOak Wilt
Identification & ManagementIdentification & Management
Robert EdmonsonRobert Edmonson
Biologist II / Certified ArboristBiologist II / Certified Arborist
Texas A&M Forest ServiceTexas A&M Forest Service
Master NaturalistsHill Country Chapter
The Impact of Oak WiltThe Impact of Oak Wilt
• ““Oak wilt is one of the most destructive tree diseases” Oak wilt is one of the most destructive tree diseases” (Young, 1949).(Young, 1949).
• “… “…. this disease has the potential of becoming one of the. this disease has the potential of becoming one of the worst diseases to attack the forests of the state.”worst diseases to attack the forests of the state.” ( True and Gillespie, 1961).( True and Gillespie, 1961).
• “ “Ceratocystis fagacearumCeratocystis fagacearum, the cause of oak wilt, is a fungus , the cause of oak wilt, is a fungus with the potential to be one of the most destructive of all with the potential to be one of the most destructive of all tree pathogens.” (Gibbs and French, 1980).tree pathogens.” (Gibbs and French, 1980).
• ““Oak wilt is now one of the most serious forest diseasesOak wilt is now one of the most serious forest diseases in the country” ( Johns and Phelps, 1992).in the country” ( Johns and Phelps, 1992).
The Impact of Oak WiltThe Impact of Oak Wilt
ThousandsThousands of acres of oaks of acres of oaks have succumbed to oak wilt have succumbed to oak wilt throughout central and west throughout central and west
Texas.Texas.
The Impact of Oak WiltThe Impact of Oak Wilt
Oak wilt may Oak wilt may reduce urban and reduce urban and
suburban property suburban property values by 15-20%.values by 15-20%.
What Is Oak Wilt?What Is Oak Wilt?
• Caused by the fungus Caused by the fungus Ceratocystis fagacearumCeratocystis fagacearum
• Primary vascular pathogenPrimary vascular pathogen
• Relies on insects for transportationRelies on insects for transportation
• Produces fungal matsProduces fungal mats
• Heat sensitiveHeat sensitive
• Unknown originUnknown origin
Where is Oak Where is Oak Wilt?Wilt?
What Oaks Are Susceptible?What Oaks Are Susceptible?
AllAll Oaks! Oaks!
Red oaksRed oaks are extremely susceptible to oak wilt, probably due to are extremely susceptible to oak wilt, probably due to large summerwood vessels. They also play a unique role in disease large summerwood vessels. They also play a unique role in disease
spread by forming fungal mats. spread by forming fungal mats.
White oaksWhite oaks have very small vessels and seem to tolerate oak wilt; have very small vessels and seem to tolerate oak wilt; however, they are NOT IMMUNE to the disease! however, they are NOT IMMUNE to the disease!
Live oaksLive oaks are semi-ring porous and intermediate in susceptibility. are semi-ring porous and intermediate in susceptibility. They spread by root sprouts and readily root graft with other live They spread by root sprouts and readily root graft with other live
oaks. They are seriously affected by oak wilt due to these vast, oaks. They are seriously affected by oak wilt due to these vast, interconnected root systems that allow movement of the fungus interconnected root systems that allow movement of the fungus
among trees. among trees.
Above GroundAbove Ground (long distance) via sap-feeding beetles. (long distance) via sap-feeding beetles.
Fungal spores are picked up from certain infected Fungal spores are picked up from certain infected RedRed oaks and carried to fresh wounds on other oak species. oaks and carried to fresh wounds on other oak species.
New infection centers are started in this manner. New infection centers are started in this manner.
How Is Oak Wilt Spread?How Is Oak Wilt Spread?
Sap Beetle Sap Beetle
Fungal Mat Fungal Mat Fresh Wound Fresh Wound
on Oak on Oak
How Is Oak Wilt Spread?How Is Oak Wilt Spread?UndergroundUnderground (localized) via interconnected root systems. (localized) via interconnected root systems.
This occurs primarily in This occurs primarily in LiveLive oaks and is responsible for the oaks and is responsible for the majority of spread and tree deaths in central Texas.majority of spread and tree deaths in central Texas.
Root Grafts Root Grafts Live Oak Mott Live Oak Mott
Rate of spread averages Rate of spread averages approximately 50 feet to 75 feet approximately 50 feet to 75 feet
per yearper year
Red Oak CenterRed Oak CenterLive Oak CenterLive Oak Center
Pattern of Disease in the Pattern of Disease in the Population of TreesPopulation of Trees
Rapid defoliationRapid defoliationDeath in 3 to 6 monthsDeath in 3 to 6 months
Eventual spread to adjacent treesEventual spread to adjacent treesNo fungal mat formationNo fungal mat formation
~ 20% survival rate~ 20% survival rate
Pattern in Individual TreesPattern in Individual Trees
Live OaksLive Oaks
Red OaksRed Oaks
Maintain dead leavesMaintain dead leavesDeath in 3 to 4 Death in 3 to 4 weeksweeks
Possible spread to adjacent treesPossible spread to adjacent treesPossible formation of fungal matsPossible formation of fungal mats
100% mortality (no survivors)100% mortality (no survivors)
Pattern in Individual TreesPattern in Individual Trees
Foliar Symptoms Foliar Symptoms in Live Oaksin Live Oaks
Veinal chlorosis / necrosisVeinal chlorosis / necrosis
Tip burnTip burn
Marginal necrosisMarginal necrosis
Vein bandingVein banding
Foliar Symptoms in Foliar Symptoms in Red OaksRed Oaks
Bronzing or water soakingBronzing or water soaking
Contain spores for spread by the beetleContain spores for spread by the beetle
Produced Produced onlyonly on red oaks on red oaks
Mats form under bark Mats form under bark
Multiple mats per tree Multiple mats per tree
Produce a sweet odor like rotting melonsProduce a sweet odor like rotting melons
Mat production accelerated by cool, moist weatherMat production accelerated by cool, moist weather
In Texas, trees killed in late summer produce mats In Texas, trees killed in late summer produce mats the following springthe following spring
Presence of Fungal MatsPresence of Fungal Mats
Taking SamplesTaking SamplesBole and/or branch samplesBole and/or branch samples
Confirms presence of Confirms presence of pathogenpathogen
How to Manage Oak WiltHow to Manage Oak Wilt
Early detection and prompt action are essential for successful Early detection and prompt action are essential for successful management of oak wilt.management of oak wilt.
There are four primary approaches used to manage oak wilt:There are four primary approaches used to manage oak wilt:
These measures will These measures will notnot cure oak wilt but can cure oak wilt but can significantly reduce tree losses.significantly reduce tree losses.
PreventionPrevention
TrenchingTrenching
InjectionInjectionPlantingPlanting
PreventionPrevention
Peak beetle activity and Peak beetle activity and fungal mat production occur fungal mat production occur
in the spring; therefore, in the spring; therefore, avoid wounding oaks from avoid wounding oaks from
February through June.February through June.
Regardless of season, Regardless of season, immediately immediately paintpaint all pruning all pruning cuts and other wounds to oaks. cuts and other wounds to oaks. This discourages contaminated This discourages contaminated
sap-feeding beetles from visiting sap-feeding beetles from visiting these wounds and introducing these wounds and introducing
oak wilt into these trees. oak wilt into these trees.
PreventionPreventionDestroy infected Destroy infected RedRed oaks to prevent oaks to prevent
fungal mat formation fungal mat formation
Do not use infected Do not use infected RedRed oaks for oaks for firewood! firewood!
PreventionPrevention
Transport and use only Transport and use only dry, well-seasoned dry, well-seasoned
firewoodfirewood
Leave unseasoned wood Leave unseasoned wood on site one year before on site one year before
transportingtransporting
Do not store infected Do not store infected wood near healthy treeswood near healthy trees
Cover wood with clear Cover wood with clear plastic and bury the plastic and bury the
edges to prevent insects edges to prevent insects from leaving the pilefrom leaving the pile
TrenchingTrenching
Trenches must be placed a Trenches must be placed a minimumminimum of 100 feet of 100 feet ahead of the disease and dug at least 4 feet deep ahead of the disease and dug at least 4 feet deep
(sometimes deeper) to sever all root connections! (sometimes deeper) to sever all root connections!
100’100’
Diseased TreeDiseased Tree
Healthy TreeHealthy Tree
TrenchTrench
100’ minimum
TrenchingTrenching
Soil depth and texture Soil depth and texture determine equipment choice determine equipment choice
for trench installations for trench installations
TrenchingTrenching
Removing all oaks, especially Removing all oaks, especially healthy oaks along the trench can healthy oaks along the trench can
improve barrier effectiveness improve barrier effectiveness
InjectionInjectionInjection is used to Injection is used to protect high-value protect high-value
oaks in advance of an oaks in advance of an expanding oak wilt expanding oak wilt
centercenter
The best candidates The best candidates for treatments are for treatments are
healthy or non healthy or non symptomatic live oaks symptomatic live oaks
within 50’ to 150’ within 50’ to 150’ from symptomatic from symptomatic
treestrees
Injection does Injection does notnot stop root transmission stop root transmission
of the fungus!of the fungus!
InjectionInjection
Success depends upon the Success depends upon the health of the tree, application health of the tree, application rate and injection technique.rate and injection technique.
InjectionInjectionSeveral products are currently Several products are currently labeled and registered for this labeled and registered for this
treatment; however, only treatment; however, only macro-injections of Alamomacro-injections of Alamo® ®
have been scientifically proven have been scientifically proven effective and continue to be the effective and continue to be the
industry standard.industry standard.
Bark is thinner below the Bark is thinner below the soil linesoil line
Increases the number of Increases the number of potential injection sitespotential injection sites
Spreads out the wounding, Spreads out the wounding, especially if future especially if future
injections are neededinjections are needed
Research has demonstrated Research has demonstrated superior distribution of superior distribution of
fungicide in the treefungicide in the tree
Macro-Injection Macro-Injection AdvantagesAdvantages
Alternative Products and TechniquesAlternative Products and Techniques
Tebuject
Criteria for Successful Criteria for Successful Oak Wilt InjectionsOak Wilt Injections
• ReliableReliable
• Verifiable documentation of research resultsVerifiable documentation of research results
• Must increase survival of treated trees over natural populationMust increase survival of treated trees over natural population
• SafeSafe
• EconomicalEconomical
• Reasonably easy to applyReasonably easy to apply
• Legal Legal
Tree PlantingTree Planting
Select trees that are Select trees that are native or adapted to native or adapted to
the regionthe region
Avoid planting Avoid planting monocultures; create monocultures; create
diversity in the diversity in the landscapelandscape
Avoid wounding oaks Avoid wounding oaks during planting during planting
Native or adapted to the local Native or adapted to the local environmental conditionsenvironmental conditions
Tolerant of temperature Tolerant of temperature extremes, amount and pattern of extremes, amount and pattern of
precipitation and local soil precipitation and local soil conditionsconditions
Not invasive nor detrimental to Not invasive nor detrimental to the local environmentthe local environment
Preferably multi-functional in Preferably multi-functional in the landscapethe landscape
Tree PlantingTree Planting
Tree PlantingTree Planting SiteSite
SeasonSeason
HoleHole
DrainageDrainage
Pruning?Pruning?
Foreign MaterialsForeign Materials
DepthDepth
BackfillBackfill
Staking?Staking?
MulchMulch
ProtectionProtection
MaintenanceMaintenance
Tree PlantingTree Planting
Recommended TreesRecommended Trees
American smoketreeAmerican smoketree
Arizona walnutArizona walnut
baldcypressbaldcypress
bigtooth maplebigtooth maple
bur oakbur oak
Carolina buckthornCarolina buckthorn
cedar elmcedar elm
chinkapin oakchinkapin oak
desert willowdesert willow
escarpment cherryescarpment cherry
Lacey oakLacey oak
littleleaf leadtreelittleleaf leadtree
mescalbeanmescalbean
Mexican plumMexican plum
pecanpecan
possumhawpossumhaw
TX or MX redbudTX or MX redbud
rusty blackhaw rusty blackhaw
Texas crabapple Texas crabapple
Texas sophoraTexas sophora
Texas A&M Forest Service’s RoleTexas A&M Forest Service’s Role““The overall goal of the Texas A&M Forest Service’s The overall goal of the Texas A&M Forest Service’s
Cooperative Oak Wilt Suppression Project is to minimize Cooperative Oak Wilt Suppression Project is to minimize the spread of oak wilt (the spread of oak wilt (Ceratocystis fagacearumCeratocystis fagacearum) in central ) in central
Texas.”Texas.”• Provide public awareness and education about the diseaseProvide public awareness and education about the disease
• Identify and map mortality centers with ground Identify and map mortality centers with ground verification of oak wiltverification of oak wilt
• Provide treatment recommendations and cost-shares (when Provide treatment recommendations and cost-shares (when applicable) to private landownersapplicable) to private landowners
• Conduct post-suppression evaluations on cost-shared Conduct post-suppression evaluations on cost-shared treatmentstreatments
• Establish and maintain detailed and accurate recordsEstablish and maintain detailed and accurate records
Cost SharesCost SharesFederal cost-shares disbursed through the Texas A&M Federal cost-shares disbursed through the Texas A&M Forest Service’s Oak Wilt Suppression Project may be Forest Service’s Oak Wilt Suppression Project may be
available to private landowners for the following available to private landowners for the following suppression efforts:suppression efforts:
• Containment trenching around oak wilt centersContainment trenching around oak wilt centers
• Pushing or rouging of Pushing or rouging of allall oaks within the boundaries oaks within the boundaries of cost-shared trenchesof cost-shared trenches
• Removal of diseased red oaks in urban areas Removal of diseased red oaks in urban areas
Cost-shares shall consist of 40% of actual costs not to Cost-shares shall consist of 40% of actual costs not to exceed $2000.00 per individual per year with a maximum exceed $2000.00 per individual per year with a maximum
of $10,000.00 per projectof $10,000.00 per project
Cost SharesCost Shares
• Complete containment of the disease center (natural land Complete containment of the disease center (natural land features and features and existing underground infrastructure can be used in select existing underground infrastructure can be used in select cases)cases)
• Relative isolation of the disease centerRelative isolation of the disease center
• High potential of fungal mat formation (red oaks)High potential of fungal mat formation (red oaks)
• Compliance with Cultural Resources Preservation ActCompliance with Cultural Resources Preservation Act
The following criteria must be met in The following criteria must be met in order to qualify for cost-shares:order to qualify for cost-shares:
Cost SharesCost Shares
Items Items NOTNOT eligible for cost-shares include: eligible for cost-shares include:
Removal of dead treesRemoval of dead trees
Trenching around healthy stands of treesTrenching around healthy stands of trees
Secondary trenchesSecondary trenches
Engineering charges, consulting fees or permit feesEngineering charges, consulting fees or permit fees
Loss or reduction in revenues from the landLoss or reduction in revenues from the land
Stump grindingStump grinding
Fungicide treatments (injection)Fungicide treatments (injection)
Replanting or landscapingReplanting or landscaping
Cost SharesCost Shares
Cost-share ApplicationCost-share Application
Treatment PlanTreatment Plan
Cultural Resources Survey FormCultural Resources Survey Form
TARL Records CheckTARL Records Check
Treatment MapsTreatment Maps
General Location MapGeneral Location Map
Underground Utility Waiver Underground Utility Waiver
Cultural Resources Acknowledgement FormCultural Resources Acknowledgement Form
W-9 Tax Identification FormW-9 Tax Identification Form
As with all cost-share programs, there is As with all cost-share programs, there is an application processan application process
Texas A&M Texas A&M Forest Service Forest Service Central Texas Central Texas
RegionsRegions
Oak Wilt Oak Wilt ResourcesResources
Oak Wilt ResourcesOak Wilt Resources
Oak Wilt Information Partnership website:Oak Wilt Information Partnership website:
www.texasoakwilt.orgwww.texasoakwilt.org
How To Identify and Manage Oak Wilt in How To Identify and Manage Oak Wilt in TexasTexas brochure brochure
Other Informational WebsitesOther Informational Websites
http://texasforestservice.tamu.eduhttp://texasforestservice.tamu.edu
http://texastreeplanting.tamu.eduhttp://texastreeplanting.tamu.edu
www.texasinvasives.orgwww.texasinvasives.org
www.treesaregood.orgwww.treesaregood.org
www.texasconservation.orgwww.texasconservation.org
QuestionsQuestions
??????
Thank You!Robert EdmonsonRobert Edmonson
Biologist II / Certified ArboristBiologist II / Certified Arborist
Texas Forest ServiceTexas Forest Service