STEM AND BRANCH PATHOLOGY

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STEM AND BRANCH PATHOLOGY
TOPICS

1. Organisms involved
2. Causes
3. Types of diseases and causal genera and species
4. Management

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  1. Causes - both abiotic and biotic
agents   Abiotic agents - wind and branch and
stem breakage (increased by decay), ice and snow
breakage, lightning, lawn mower and weed whacker
injury, etc. Biotic agents phytoplasmas,
bacteria, fungi, mistletoes, (not many viruses in
stems and branches of woody plants).
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2. Organisms involved  
a. Phytoplasmas yellows, wilts  
b. Bacteria  - galls
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c. Fungi True Fungi Ascomycota and
Deuteromycota (Fungi Imperfecti) - cankers
  Basidiomycota decay fungi Fungus-like
organisms Oomycota (stem cankers occasionally
Sudden oak death)
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  d. Parasitic plants true mistletoes
hardwoods dwarf mistletoes conifers
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• 3. Types of diseases and common causal genera or
  species
• Stem Decay
• Ganoderma applanatum (Artist conk conifers and
  hardwoods)
• Postia sericeomolis Pocket rot of W. redcedar
• Phellinus igniarius - common on willow, alder and
  other hardwoods
• Fomes fomentarius white spongy trunk rot
• Hardwoods birch, alder, poplar
• Fomitopsis pinicola Red belt fungus (mostly
  dead conifers)
• Phaeolus schweintizii (conifers).

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• b. Mistletoes - conifers (dwarf mistletoes -
  Arceuthobium), hardwoods (true mistletoes -
  Phoradendron)
• c. Cankers (Nectria, Cytospora, Hypoxylon
  (hardwoods), Neofusicoccum (madrone) ,
  Phytophthora
• Galls (Agrobacterium tumefacians (many hosts),
  western gall rust caused by Endocronartium
  harknessii - lodgepole pine

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e. Rusts (White pine blister rust (5 needle
pines) - Cronartium ribicola, western gall rust -
Endocronartium harknessii, f. Vascular wilts -
Dutch elm disease (Ophiostoma ulmi), Verticillium
wilt, fireblight of cherries
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STEM DECAYS
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Ganoderma applanatum Artist Conk
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Artist conk on crabapple on campus
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Postia sericeomolis Pocket rot of cedar
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Phellinus igniarius - common on willow, alder and
other hardwoods
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Fomes fomentarius white spongy trunk
rot Hardwoods birch, alder, poplar
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Fomitopsis pinicola Red belt fungus
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Phaeolus schweinitzii
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COMPARTMENTALIZATION OF DECAY
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Compartmentalization Of Decay In Trees - CODIT
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Wall 1 -Vertical ends of Cells tracheids
and vessels - weakest
Wall 2 - Internal annual rings
Wall 3 - Ray parenchyma cells
o
Phenolic chemicals laid down (fungicidal)
Wall 4 - Annual ring at the time of wounding -
strongest
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WILDLIFE ASSOCIATED WITH DECAY IN LIVING TREES
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WILDLIFE USING DECAYED TREES Bats Black
bears Woodpeckers - number of species American
Martens Vauxs swifts Owls Red-breasted nuthatch
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CREATION OF DECAY AND HABITAT
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SNAG CREATION METHODS 1. Topping at
base of live crown or mid live crown 2. Girdling
at different heights 3. Herbicides 4.
Pheromones to attract bark beetles 5. Killing
dwarf mistletoe infected trees 6. Planting
artifical snags ARTIFICIAL INOCULATION OF SNAGS
AND GREEN TREES
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Decay and hazard treese.g. Phaeolus schweinitzii
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DETECTION OF DECAY 1. Increment borers 2.
Wood drills 3. Shigometer - electrical
resistance 4. Resistograph - physical
resistance 5. Ultrasound travel 6. Sonic
tomography
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Increment borers
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Battery Power Drills
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SHIGOMETER
USDA Forest Service
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Resistograph - Trademark
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ULTRASOUND
USDA Forest Service
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TOMOGRAPHY http//www.fujikura.co.uk/speci
al/picus/picus.htm http//www.argyll-arborists.co.
uk/PicusSonicTomograph.htm