Cri$cal Entry Point Inspector Training

Transcription

1 Cri$cal Entry Point Inspector Training August 13 15, 2012 Texas Plant Disease Diagnos$c Laboratory Texas A&M AgriLife Extension Service College Sta$on, TX Dr. David N. Appel Department of Plant Pathology and Microbiology Texas A&M AgriLife Extension Service College Sta$on, TX 77843

2 History of Introduced, Destruc$ve Exo$c Tree Pathogens Chestnut blight, accidently introduced in 1900, by 1940, near ex$nc$on, Dutch elm disease, introduced in 1928, massive destruc$on of popular urban tree, White pine blister rust, Introduced in North America in 1900, Costly impact on 5 needle pines

3 What Priority Pathogens are Currently Threatening Texas Trees? What Cons$tutes a Threat? Distribu$on, is the pathogen in the U.S.? has the pathogen been reported in Texas? Poten$al for high level of tree mortality, is it easily transmiued? are there high value, suscep$ble host popula$ons? what is our capacity to detect the pathogen? Environmental and economic impacts, is the pathogen of regulatory significance?

4 Provided by the American Phytopathological Society

5 Texas Pest Lists Texas Invasive Pest Council, August, 2011 PATHOGENS Of concern and not known to be in Texas Sudden Oak Death (Phytophthora ramorum) Thousand Cankers Disease (Geosmithia morbida) Philippine downy mildew (Pernosclerospora philippinesis) Brown stripe of corn (Scleropthora rayssiae var. zeae) Citrus canker (Xanthomonas axonopodis pv. Citri) Ralstonia solanacearum race 3 biovar 2 Citrus variegated chlorosis (Xylella fastidiosa CVC strain) Huanglongbing (Citrus greening C. Liberibacter asiaticus and africanus) Grape phytoplasma yellows (C. Phytoplasma australiensis) Laurel wilt (Raffaelea lauricola) Of concern and within Texas in low/limited incidence Brown spot of rice (Cochliobolus miyabeanus ana. Bipolaris oryzae) Soybean rust (Phakospora pachyrhizi) Palm phytoplasma (Lethal decline of date palms Phytoplasma group 16SrIV) Bacterial leaf streak, bacterial blight rice (Xanthomonas oryzae) Pierce s disease (Xylella fastidiosa) Zebra chip on potatoes (C. Liberibacter solanacearum) PLANTS (not shown) INSECTS (not shown)

6 Disease Topics Scheduled (Dr. Ong) Thousand Cankers Oak Wilt Added (Appel) Phytophthora diseases (e.g. Sudden Oak Death) Laurel wilt Dutch elm disease qoegnqoerin

7 Thousand Cankers Disease of Black Walnut First iden$fied in Colorado in 2008, Results from combined ac$vity of an insect and a fungus, Pityophthorus juglandis = Walnut Twig Beetle (WTB), Geosmithia morbida = fungus, Range of the beetle is expanding, CA, OR, WA, ID, UT, AR, NM, NV, CO, TN, VA,PA No current controls, Destroy infected trees, Avoid movement of firewood.

8 U.S. Distribu$on of TCD by State (See dark borders)

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10 Signs and Symptoms The three major symptoms of this disease are branch mortality, numerous small cankers on branches and the bole, and evidence of $ny bark beetles.

11 TCD Current Response US Forest Service Resources for survey of walnut trees and WTB trapping in forested areas, APHIS PPQ Resources for survey of walnut trees and WTB trapping in urban areas, residen$al and industrial sedngs, First responders should report suspicious trees to the State Forester, State Plant Health Director, or Coopera$ve Extension Office.

12 Ranges of Suscep$ble Black Walnuts in Texas

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14 Significance to Texas Distribu$on, not here yet, but in bordering states, Poten$al for mortality, will be high with arrival of beetle Environmental and economic impact, environmental impact could be significant, economic impact unknown or low, Regulatory significance/interest? high at first, but in long run probably low, Pecans not suscep$ble, Walnuts not a big factor in nursery trade.

15 Phytophthora Threats to Texas Trees A na$ve Phytophthora species has long been considered to be responsible for Post oak mortality in Central Texas, Many na$ve Phytophthora species are common in nursery trade, none of regulatory significance, Then came Sudden Oak Death, And there are many others!

16 Sudden Oak Death (SOD) Caused by Phytophthora ramorum. Potential to cause enormous losses of trees in Texas. Causing heavy losses of oaks in California. Found only in 12 Texas nurseries. Marin County, CA (north of San Francisco) Photos: Marin County Fire Department

17 Phytophthora ramorum Sporangia releasing zoospores Phytophthora ramorum in culture Photo: UC Davis & UC Berkeley Chlamydospores

18 Origins and Expansion of the Sudden Oak Death Pathogen First discovered and described in Europe, Determined to be responsible for oak mortality in California, first found in 1995, described in 2000, has been extremely destruc$ve, and spread to WA and OR, Distributed throughout U.S. on contaminated nursery stock,

19 Sudden Oak Death Distribution in U.S. Nationwide Distribution, Nurseries (2004) West Coast Distribution, Woodlands

20 Biology of Phytophthora ramorum Not a true fungus, Prefers cool moist condi$ons, Spreads by wind driven rain, water, human ac$vi$es (esp. movement of contaminated nursery stock), Can survive for long periods in the soil.

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22 Two sets of symptoms caused by Phytophthora 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

23 P. ramorum on coast live oak Photo: Pavel Svihra, UC Cooperative Extension

24 Phytophthora ramorum bleeding Photos: Mike McWilliams, ODF & Bruce Moltzen, Missouri Dept. of Conservation

25 Phytophthora ramorum Bark symptoms outer bark inner bark Photo: Bruce Moltzen, Missouri Department of Conservation

26 Similar symptoms not P. ramorum outer bark inner bark Bleeding canker caused by inner-bark boring insect Photo: Steve Oak, USDA-Forest Service

27 Other common diseases & injuries Bacterial wetwood Boring insects Mechanical injury Fungi

28 On other plant hosts, P. ramorum causes symptoms of foliar blight Camellia Rhododendron Viburnum Pieris Mountain laurel Lilac Pyracantha Honeysuckle Yew Douglas-fir Grand fir Coast redwood

29 Photo: Cheryl Blomquist, CDFA Symptoms on camellia

30 Similar symptoms Sun scorch on camellia Photo: Carrie Harmon, University of Florida

31 P. ramorum symptoms on viburnum Viburnum plicatum tomentosum Mariesii Photo: Jennifer Parke, Oregon State University

32 P. ramorum symptoms on viburnum stem canker Photo: Sabine Werres, Institut für Pflanzenschutz im Gartenbau, Germany

33 P. ramorum symptoms on lilac Photo: Alexandra Schlenzig, Scottish Agricultural Science Agency

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37 Significance to Texas Distribu$on, some are already here, others yet to be introduced, will be a constant challenge, Poten$al for mortality, easily disseminated, par$cularly in nurseries, very high poten$al, Environmental and economic impact, poten$al is very high for both, although environment in Texas supposedly not ideal, Regulatory significance? It already has been highly regulated, and will con$nue to be important.

38 Example of a Na$ve Disease - Oak Wilt Ceratocys8s fagacearum, vascular parasite, Sensi$ve to high temperatures, Very poor saprophyte, Two ma$ng types, Two types of spores.

39 Range of Oak Wilt in Texas and Impact on Major Popula+on Centers Major Popula+on Centers in Texas

40 Oak species affected by oak wilt in Texas RED OAKS = Suscep+ble Q. texana Spanish Oak Q. marilandica Blackjack Oak Q. nigra Water Oak WHITE OAKS = Resistant Q. sinuata var. breviloba Shin Oak Q. glaucoides Lacey Oak Q. polymorpha Mexican white oak Q. stellata Post Oak LIVE OAKS= variable Q. virginiana Southern live oak Q. fusiformis Plateau live oak

41 Ni$dulid Beetles Oak Wilt Disease Cycle Infec$on of Quercus spp. by Ceratocys8s fagacearum in Texas Dead Red Oak (next spring) 1. Red Oak Phase Mat Forma$on No mats, no beetles Dying Red Oak (Fall) Contaminated Ni$dulids = Overland spread wound 2. Live Oak Phase Local spread = Rapid, spreading Live oak mortality Infected Red Oak (late summer) Healthy red oak Root Connec$ons Dead Infected Red Oak (early summer) Root connec$ons Healthy live oak Diseased Live Oak Prepared by D.N. Appel March 2011

42 Fungal Mats Contain spores for spread by the beetle, Produced only on red oaks, - trees killed in late summer, Mycelial mats form under bark, - accelerated by cool, moist conditions, Multiple mats per tree, Produce a sweet odor like rotting melons.

43 Beetle Spread Nitidulid Beetle

44 Beetle Spread Beetles are only opportunistic Sap feeding beetles Attracted to sweet smelling odors- ripe fruit, fresh wounds on trees Peak beetle populations is in the spring High temperatures limit beetle activity Visit healthy trees rather than dead trees

45 Beetle Spread

46 Oak Wilt Control Op$ons Always starts with diagnosis Preven$on - avoid wounding in spring Preven$on - use wound paints Preven$on - cau$ous movement of firewood Direct control - trenching Direct control - intravascular injec$on with fungicides Plant resistant/immune trees

47 Significance to Texas Distribu$on, widely distributed, but not in South Texas, East Texas, or upper Gulf Coast, Poten$al for mortality, is highly destruc$ve, has many means of spread, par$cularly the firewood, Environmental and economic impact, both are huge, Regulatory significance? it is high for movement of nursery stock out of TX, low within State in spite of risks.

48 Laurel Wilt: A Devasta$ng Disease of Lauraceous Trees

49 Laurel Wilt First Discovered in 2002 in Georgia

50 Laurel Wilt Infec$on Mature trees wilt and dies within 5 12 weeks

51 Laurel Wilt Addi$onal Symptoms Dark sapwood discolora$on Ambrosia Beetle auack

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54 When Will Laurel Wilt Reach Texas?

55 Significance to Texas Distribu$on, not here yet, Poten$al for mortality, high, but on limited hosts, Environmental and economic impact, probably very low Regulatory significance? maybe high at first, but low in long run.

56 Dutch Elm Disease The Pathogen Ophiostoma novo- ulmi, Vascular parasite, Invaded North America in mid 1920s, Spread throughout na$ve elm popula$on,

57 DED Hot Spots

58 Dutch elm disease Disease Biology Elm bark beetles are vectors, Also spreads through root graos, Inoculum forms in beetle galleries, Every tree source of inoculum.

59 Dutch elm disease Management Detec$on, Isola$on, Removal, Disposal, Injec$on, Host resistance.

60 Significance to Texas Distribu$on, Limited, Poten$al for mortality, is highly destruc$ve, has many means of spread, par$cularly the firewood, Environmental and economic impact, Both could be very high, Regulatory significance? it depends, further research is needed, probably will be very low.

61 Giant Asian Dodder on Arizona Ash The End