Sudden Oak Death Update, Phytophthora ramorum
Dr. Tim Schubert, Timothy.Schubert@freshfromflorida.com, Florida Department of Agriculture & Consumer Services, Division of Plant Industry
Florida Pest Alert - Update, 3/17/04
INTRODUCTION: In March 2004, CDFA and USDA announced that Sudden Oak Death (SOD) had been detected in several large commercial nurseries in southern California (Sudden Oak Death Find in California.pdf 
). These nurseries (to be identified as information becomes available) had shipped much potentially infected stock to many states around the country, including Florida. This update is designed to present additional images of symptoms induced by the SOD pathogen on various commercial nursery stock likely to enter Florida, and to present an updated SOD host list.
Gallery of symptoms of Phytophthora ramorum on rhododendron, camellia and oak:
Photos - Department of Environment, Food and Rural Affairs, UK |
|
Symptoms caused by Phytophthora ramorum on camellia leaves (Fig. 1) and whole plant (Fig. 2). Margins of lesions are indistinct and diffuse, not sharply defined. Leaf lesions can progress down the petiole into the stems. Defoliation symptoms are also possible. |
 Fig. 3. |
 Fig. 4. |
 Fig. 5. |
Symptoms caused by Phytophthora ramorum on rhododendron foliage (Figs.3-5). Look for lesions that have rather diffuse margins, in many cases with a lighter-colored central portion to the lesion.
Photos - Bruce Moltzan, MO Dept of Conservation (Fig. 3) and University of GA (Figs. 4-5)
 Fig. 6. |
 Fig. 7. |
More foliar symptoms of P. ramorum on rhododendron (Fig. 6) and camellia (Fig. 7). Photos - Department of Environment, Food and Rural Affairs, UK |
 Fig. 8. |
 Fig. 9. |
Symptoms of weeping P. ramorum-infection on trunk of southern red oak, (Quercus falcata) in the Netherlands (Fig. 8). Bark removed (Fig. 9). This common Florida native is not likely to be shipped as nursery stock to Florida from SOD-infested areas, but might be a first victim of local disease spread. Photos - Department of Environment, Food and Rural Affairs, UK |
Target these hosts for SOD Surveys:
Updated SOD host genera list - CA, OR and WA (* = common in some parts of FL)
| *Acer - maple *Aesculus - buckeye, horse chestnut Arbutus Arctostaphylos *Camellia - camellia *Hamamelis - witch hazel |
Lithocarpus *Lonicera - honeysuckle *Pieris - fetterbush Pseudotsuga *Quercus - oak *Rhamnus - buckthorn |
*Rhododendron - azalea Sequoia Trientalis Umbellularia *Vaccinium - blueberry *Viburnum - viurnum |
Host genera identified in other countries (* = common in some parts of Florida)
| Abies Corylus *Fagus - beech *Kalmia - mountain laurel |
*Leucothoe - doghobble *Pittosporum - pittosporum *Rubus - blackberry *Syringa - lilac |
*Taxus - yew *Toxicodendron - poison ivey, poison oak, poison sumac |
Host list from this document
Frequently Asked Questions
More Sudden Oak Death Information
