Plant Health Research at The Morton Arboretum

Transcription

1 Plant Health Research at The Morton Arboretum Stephanie Adams, MS PHC Research Specialist ISA Certified Arborist The Morton Arboretum October 23, 2013

2 Volcano Mulch Impact on Trees VoMIT

3 Mulching Benefits Moisture Temperature insulation Favorable environment for microbes Building soil Reduces compaction Mulching culture Unfortunately

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5 What s the problem? Traps moisture on the stem Encourage infection Expedite rot Hiding places for animals Suffocation Strong belief that VM is bad for trees

6 Why do this project? Mulching is an important part of tree health in landscapes for tree and shrub health Volcano mulching is an unfortunate common practice seen in the landscape Does volcano mulch create an environment that is more conducive to disease development?

7 Sources of inoculum Worked with municipal arborists and foresters to find volcano mulched trees Looked for cankers, lesions, and oozing on the bark under the mulch Collected discolored wood from street trees with <8 of mulch on the stem for culturing Koch s postulates proving a specific pathogen causes a specific disease on a specific host

8 Tree stem Mulch Mulch depth (D) Root flair depth (RD) Volcano height (H) Root flair Soil line Root ball

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10 Fungi were isolated from the wood samples DNA was extracted using Qiagen s DNeasy Plant Mini Kit DNA sequencing at The Field Museum of Natural History, Chicago, IL

11 Inoculum Best pathogens selected for each tree species Crabapple: Lecythophora Honey-locust: Fusarium solani Linden: Botryopheria stevensii Maple: Sporamia subticinensis River birch: none

12 Materials Quonset trees Whips Two container heights 2 & 4 mulch Field trees Planted 3 yrs ½ - ¾ at planting 6 & 12 mulch

13 Inoculations Aseptic techniques used Bark flap cut Fungal-culture or sterile PDA plug inserted Paper-based lab tape Re-mulched

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15 Harvesting and measurements Harvested 12 months after inoculation Cookies being cut to see discoloration Small trees scroll saw Large trees chop saw Measurements of discolored areas

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18 Preliminary results Subsample of trees run Quonset Two species (linden, honey-locust) Most trees healed over the wound Production of all four walls of compartmentalization (CODIT Shigo) Pockets of decay found in stem

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20 Callous Decay pocket Bark flap

21 Measurements Base b Height h

22 Measuring decay Cutting cookies to find decay HawkEye 1600 (dedicated digital camera) Front Runner s Visionscape 3.6 Account for kerf, thickness of cookie for volume (mm 2 )

23 Results Cutting and measurements done by December 2013 Published in 2014

24 Staff working on VoMIT Sara Dreiser Marvin Lo Rick Grunt Bethany Brown Marlene Hahn John Sipples Steve Ruffolo

25 American elms Developing improved American elm cultivars Surveying for Dutch elm disease (DED) and elm phytoplasmas (elm yellows, clover proliferation, other) Testing commercially available DED-resistant elms for elm phytoplasma resistance Testing resistant elms for root-inoculation resistance

26 Dutch elm disease Assessing 45 American elms for Dutch elm disease resistance Trees started as seed collected 1980, Champaign-Urbana Gene Himelick, IL Natural History Survey, U of IL Inoculation trials Propagating Controlled crosses

27 Inoculation trials Parent trees inoculated twice with Ophiostoma in 2009 Branches collected in fall 2009 and spring 2010 Measure streaking Assess symptoms in trees Choose trees with good resistance and characteristics (color, shape, etc.)

28 Controlled crosses 2012

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30 Elm yellows phytoplasma

31 Phytoplasmas Determine prevalence of elm phytoplasmas Working with municipal arborists, foresters, park districts, forest preserves Identify symptomatic trees Test for DED (culturing) Extract DNA for real-time PCR Use infected tree material to inoculate healthy trees in quonset

32 Staff working on American elms David Marin Rick Grunt Matt Laizure Kathy Stevens Brian Malatia Beau Nagan Terry Guiney

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