sudden oak death in washington state l.
Skip this Video
Loading SlideShow in 5 Seconds..
Sudden Oak Death in Washington State PowerPoint Presentation
Download Presentation
Sudden Oak Death in Washington State

Loading in 2 Seconds...

play fullscreen
1 / 33

Sudden Oak Death in Washington State - PowerPoint PPT Presentation

  • Uploaded on

Sudden Oak Death in Washington State. What is Sudden Oak Death?. First seen in early 1990s Two types of symptoms Canker Foliar blight Caused by Phytophthora ramorum (Oomycetes) Over 70 plant hosts Most of the outbreak in central coastal CA. Dead tanoak in Muir Woods NP, CA.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

Sudden Oak Death in Washington State

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
what is sudden oak death
What is Sudden Oak Death?
  • First seen in early 1990s
  • Two types of symptoms
    • Canker
    • Foliar blight
  • Caused by Phytophthora ramorum (Oomycetes)
  • Over 70 plant hosts
  • Most of the outbreak in central coastal CA

Dead tanoak in Muir Woods NP, CA

Foliar symptoms on Rhododendron

two distinct diseases caused by phytophthora ramorum
Two distinct diseases caused byPhytophthora ramorum
  • Sudden Oak Death
    • Red oaks, beech, and tanoak
    • Stem lesions beneath the bark girdle and kill tree
    • Cankers often bleed or ooze
    • Can kill adult trees
    • “Dead end” hosts
  • P. ramorum foliar blight/Ramorum blight
    • Non-oak hosts
    • Spots and blotches on leaves & shoot die back
    • Can kill juvenile plants, usually not lethal for mature plants
    • Spreads the disease

Slide from the USDA PRED Training Module

phytophthora spore stages
Phytophthora spore stages
  • Phytophthora thrives in wet conditions
  • P. ramorum infections initiated by sporangia and zoospores
  • Chlamydospores can persist in soil and leaf litter
  • Sexual oospores are resistant to damage

Sporangia containing swimming zoospores


Oospores (P. infestans)

how p ramorum spreads
How P. ramorum spreads
  • Water - Wind-driven rain, irrigation, runoff
  • Humans – soil on hiker’s boots and bicycle tires, nursery plants
  • Wildlife
p ramorum genetics
P. ramorum genetics
  • Two mating types – A1 and A2
  • Three clonal lineages – NA1, NA2, EU1

NA1 and NA2

All A2


Mostly A1, with a few A2

There is concern about NA and EU populations mating, but this has not been observed


P. ramorum in North American forests

  • SOD currently found in 14 CA counties and 1 OR county
  • These counties are under quarantine
  • SOD not known to be established anywhere else in N.A. forests

Map from

Kelly, UC-Berkeley

Slide from the USDA PRED Training Module


Sudden Oak Death in California

  • Tanoak (Lithocarpus densiflorus) and oak species affected
  • Tree death primarily along urban-wildland interface
  • Dying trees created hazards for residents
  • Increased fire hazard in wildland areas from dead trees

Photo: Marin County Fire Department


Infested area quarantined and eradication attempted

  • 2001-2004: infested area decreased or remained the same
  • 2005-present: infested area increasing
  • Area under quarantine now 166 sq miles

SOD in Oregon

Photo: Everett Hansen, Oregon State University


Risk Group III

Risk Group II

Risk Group I

Risk of sudden oak death based on P. ramorum climate matching and hardwood forest density in the USA


Fowler, G., Magarey, R., Colunga, M. 2006. Climate-host mapping of Phytophthora ramorum, causal agent of sudden oak death In: Frankel, Susan J.; Shea, Patrick J.; and Haverty, Michael I., tech. coords. Proceedings of the sudden oak death second science symposium: the state of our knowledge. Gen. Tech. Rep. PSW-GTR-196. Albany, CA: Pacific Southwest Research Station, Forest Service, U.S. Department of Agriculture: 329-332


P. ramorum in European forests

Rhododendron ponticum

Red Oak: Quercus rubra

These species used as ornamentals in WA

Beech: Fagus sylvatica

Photo: DEFRA

Slide from the USDA PRED Training Module

washington p ramorum surveys

2002 0

2003 1

2004 25

2005 16

2006 12

2007 7

2008 4

Forest and stream

2002 ---

2003 ---

2004 ---

2005 0

2006 2

2007 6

2008 6

Washington P. ramorum surveys

Summary of P. ramorum in Washington

  • Found in nursery stock, not thought to be established
  • in natural or urban landscape
  • APHIS and WSDA conduct annual
  • surveys to inspect production nurseries
  • DNR conducts stream baiting and forest surveys
  • Many plants native to Washington are
  • known hosts
  • Potential for impact on native ecosystem
  • Quarantines may be imposed if detected in landscape

Slide by Norm Dart

recognizing symptoms
Recognizing Symptoms
  • Sudden Oak Death of oaks
  • Ramorum blight of other hosts
  • Key to determine if samples should be submitted for P. ramorum testing in Washington
      • focus on recently purchased (or near recently purchased) camellia, kalmia, lilac, pieris, rhododendron, or viburnum
symptoms on trees
Symptoms on trees

P. cambivora on Beech

  • Bleeding cankers
  • Cankers can girdle the tree and kill it
  • Host species in Fagaceae: oaks, beech, tanoak
  • Other Phytophthora spp can cause the same symptoms

P. ramorum on Oak

similar symptoms
Similar symptoms
  • Phytophthora root disease and canker
  • Armillaria root disease
bacterial stem diseases
Bacterial stem diseases
  • Bacterial wetwood
  • Bleeding stem cankers caused by Pseudomonas syringae
important hosts of p ramorum in wa nurseries
Important hosts of P. ramorum in WA nurseries
  • Rhododendron
  • Camellia
  • Viburnum
  • These genera account for over 90% of the positive finds in Washington nurseries
  • Others –
    • Pieris
    • Kalmia

Shoot blight

Leaf blotch on pacific rhododendron caused by Phytophthora ramorum. Photo by Oregon Department of Forestry.


P. ramorum symptoms on native rhododendron

Shoot dieback

Foliar blight

Foliar blight

Rhododendron macrophyllum

Photo: Everett Hansen, Oregon State University

Slide from the USDA PRED Training Module


Root rot of rhododendron

Phytophthora root rot - not caused by P. ramorum

Slide from the USDA PRED Training Module

Photo: Jay Pscheidt, Oregon State University


Leaf necrosis of Rhododendron

Sun scorch, lesion does not extend down leaf midrib

Gray blight can develop on sun scorched Rhododendron leaves

Photo: Rich Regan, Oregon State University


P. ramorum on Camellia

Brown lesions: irregular and restricted to leaf tip

Photos: Oregon Dept. of Agriculture & Cheryl Blomquist, CDFA

Slide from the USDA PRED Training Module


Symptoms on camellia

  • Look for lower leaves that have fallen off

Photo: Cheryl Blomquist, CDFA


Sun Scorch of Camellia

Brown spot not extending along petiole or midrib of leaf

Slide by Norm Dart


V. plicatum “Mariesii”

Viburnum tinus “Spring Bouquet”

V. davidii


Grey mold

  • Stem canker
  • Foliage and shoot blight


P. ramorum

some other hosts
Some other hosts

Grand fir

Bigleaf maple

Pacific madrone


should an infected plant be submitted for laboratory analysis
Should an infected plant be submitted for laboratory analysis?
  • Plants likely to be infected by Phytophthora ramorum - Rhododendron, Camellia, and Viburnum
    • Affected plant is on host list and purchased since 2002,
    • Affected plant is near a recently purchased host plant
    • Symptoms are consistent with Phytophthora ramorum:
      • Brown leaf spots with diffuse margins
      • Shoot tip dieback
sample referral and submission
Sample referral and submission
  • In Washington state Master Gardeners and Extension Agents are asked to submit suspect samples to the WSU Puyallup Plant Clinic
  • If you determine a sample should be submitted
    • Download and fill out plant clinic sample form and follow approved procedures
    • Please consult the plant clinic before sending samples

For more information please visit the WSU P. ramorum education webpage:

You may also call the WSU Plant Diagnostic Lab at (253) 445-4582 with additional questions relating to P. ramorum diagnostics or if you would like to have a plant tested.

Slide by Norm Dart