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Phytophthora ramorum: Educate to Detect (PRED) USDA-Forest Service USDA-Cooperative State Research Education & Extension Service IPM Regional Centers National Plant Diagnostic Network USDA-Animal and Plant Health Inspection Service. Overview. Introduction to PRED History of P. ramorum
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Phytophthora ramorum: Educate to Detect(PRED)USDA-Forest ServiceUSDA-Cooperative State Research Education & Extension ServiceIPM Regional CentersNational Plant Diagnostic NetworkUSDA-Animal and Plant Health Inspection Service
Overview Introduction to PRED History of P. ramorum Symptoms and look-alikes Regulations Sample collection and handling
History outline Status in North American forests Status in Europe Status in North American landscapes and nurseries
Marin County, CA (north of San Francisco) Photo: Marin County Fire Department
Marin County, CA (north of San Francisco), 2000 Photo: Marin County Fire Department
Phytophthora ramorum Sporangia releasing zoospores Phytophthora ramorum in culture Photo: UC Davis & UC Berkeley Chlamydospores
Phytophthora species Photo: William Fry, Cornell University
Phytophthora ramorum infection on the leaves of California bay laurel (Umbellularia californica) Photo: Joseph O’Brien, USDA-Forest Service
Two sets of symptoms caused byPhytophthora ramorum Sudden Oak Death Red oak group hosts and tanoak Stem lesions beneath the bark May bleed or ooze Can kill adult plants Phytophthora ramorum Foliar Blight Non-oak hosts Spots and blotches on leaves Shoot dieback Can kill juvenile plants, occasionally mature plants
P. ramorum confirmations in forests Map from www.suddenoakdeath.org Kelly, UC-Berkeley
European garden & nursery finds Phytophthora ramorum infection on rhododendron in Europe Photo: Hans DeGruyter, Netherlands Plant Protection Institute
Infected trees in Europe Quercus rubra Fagus sylvatica Photo: DEFRA
Trace-forward & trace-backinvestigations Trace forwards = to the nurseries where stock was shipped TO Trace backs = to the nursery where stock was shipped FROM
Phytophthora ramorum national survey • Most states have started or completed their surveys • Over 3000 nurseries / garden centers have been surveyed • Over 50,000 samples have been taken • As of October 2004, this survey has identified 15 confirmed finds in 7 states: California, Oregon, Washington, Maryland, Oklahoma, New Jersey and Virginia
Distribution of infected nursery stock from individual nurseries Map: USDA, APHIS, PPQ
Trace-forwards and positive detections across the U.S. July 2004 Map: USDA, APHIS, PPQ
Symptoms & look-alikes • Sudden Oak Death on oak hosts • Symptoms on other hosts • Screening questions at the NCIPM website (www.ncipm.org/sod): • focus on recently purchased (or near recently purchased) camellia, kalmia, lilac, pieris, rhododendron, or viburnum
Symptoms caused by P. ramorum differ on different hosts • True oaks (Quercus spp.) • Tanoak (Lithocarpus densiflorus) • Chestnut (Castanea) [Europe only] • Beech (Fagus) [Europe only] Sudden Oak Deathaffects members of the oak family (Fagaceae)
P. ramorum on coast live oak Photo: Pavel Svihra, UC Cooperative Extension
‘Bleeding’ canker on tree trunk ‘Bleeding’ or oozing on the bark Not associated with cracks in bark or insect holes Usually on the lower 6 ft. of tree trunks Photo: Garbelotto lab, UC Berkeley
“bleeding” Phytophthora ramorum Photos: Mike McWilliams, ODF & Bruce Moltzen, Missouri Dept. of Conservation
Phytophthora ramorum Cankers (in inner bark) are surrounded by a black line Photo: Dave Rizzo, UC Davis
Phytophthora ramorum outer bark inner bark Photo: Bruce Moltzen, Missouri Department of Conservation
Similar symptoms – not P. ramorum outer bark inner bark Bleeding canker caused by Armillaria Photo: Steve Oak, USDA-Forest Service
Similar symptoms – not P. ramorum outer bark inner bark Bleeding canker caused by inner-bark boring insect Photo: Steve Oak, USDA-Forest Service
Similar symptoms – submit sample outer bark inner bark Bleeding canker caused by Inonotus hispidus Photo: Steve Oak, USDA-Forest Service
Other common diseases & injuries • Bacterial wetwood • Boring insects • Mechanical injury • Fungi
Pyracantha Honeysuckle Yew Douglas-fir Grand fir Coast redwood Camellia Rhododendron Viburnum Pieris Mountain laurel Lilac On other plant hosts, P. ramorum causes symptoms of foliar blight
Symptoms on camellia Photos: Oregon Dept. of Agriculture & Cheryl Blomquist, CDFA
Symptoms on camellia Photo: Cheryl Blomquist, CDFA
Symptoms on camellia • Symptoms can be subtle • Look for irregular-shaped brown lesions on the leaves • Sometimes only the tips of leaves are brown • Look for lower leaves that have fallen off Photo: Cheryl Blomquist, CDFA
Similar symptoms – submit sample Sun scorch on camellia Photo: Carrie Harmon, University of Florida
Similar symptoms – submit sample Cold injury on camellia Photo: Richard Regan, Oregon State University
P. ramorum symptoms on rhododendron Shoot dieback Foliar blight Foliar blight Rhododendron macrophyllum Photo: Everett Hansen, Oregon State University
P. ramorum symptoms on rhododendron Rhododendron macrophyllum Photo: Everett Hansen, Oregon State University
P. ramorum symptoms on rhododendron Photo: Bruce Moltzen, Missouri Dept. of Conservation
P. ramorum symptoms on rhododendron Rhododendron ‘Unique’ Photo: Jennifer Parke, Oregon State University
P. ramorum symptoms on eastern native rhododendrons (inoculation trials) Photo: Paul Tooley, USDA-ARS
Similar symptoms – submit sample Foliar blight caused by Phytophthora syringae Photo: Jay Pscheidt, Oregon State University
Similar symptoms – submit sample Foliar blight caused by Phytophthora species Photo: Mike Benson, NCSU
Similar symptoms – not P. ramorum Phytophthora root rot - not caused by P. ramorum Photo: Jay Pscheidt, Oregon State University
Similar symptoms – not P. ramorum Sun scorch Gray blight can develop on sun scorched rhododendron leaves Photo: Rich Regan, Oregon State University
Symptoms on pieris Pieris japonica Photo: Oregon Dept. of Agriculture
P. ramorum symptoms on pieris Pieris japonica Photo: Oregon Dept. of Agriculture
P. ramorum symptoms on viburnum Viburnum x bodnantense ‘’Dawn’ Photo: Oregon Dept. of Agriculture