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Diagnosing Tree Problems Tree Care Advisor Core Course Training 2012


The Six W’s     

What’s the Tree? What’s the Problem? What are the Clues? When Did You Notice It? What Caused It? What if You Don’t Know?


1. What’s the Tree?  

Only Elms are likely to get Dutch Elm Disease. Only members of the Rose family can get Fireblight. Bur oaks will not be bothered by high soil pH…Red oaks will. Most common Lilacs get powdery mildew…Most Weigela don’t.


Plant Families Members Have Similar Flowers and Fruit  Often Susceptible to Same Diseases and Insects The Rose Family  Generally Include Many Genera of Different Trees and Shrubs 


What’s Likely in Minnesota?     

On Austrian Pine? On Maples? On Flowering Crabapples? On Green Ash? On Oaks?


Austrian Pine   

Diplodia Tip Blight Zimmerman Pine Tip Moth Hetrobasidion annosum Root Rot


Here’s a Guarantee… 

Emerald Ash Borer will never kill Cottonwood! Yuk!


2. What’s the Problem? 

Abnormal versus Normal


2. What’s the Problem? 

Abnormal versus Normal


2. What’s the Problem? 

Abnormal versus Normal


Abnormal Foliage


2. What’s the Problem? 

Problem versus Incidence


2. What’s the Problem? 

Predisposing: Long-term, Chronic


2. What’s the Problem? 

Predisposing: Long-term, Chronic


2. What’s the Problem? 

Inciting: Quick, One-time


2. What’s the Problem? ď Ż

Contributing: Opportunistic.


3. What are the Clues?   

Signs: Evidence of the Causal Agent Symptoms: Tree’s Reaction to Causal Agent Damage: Physical Harm Done to Tree

Photo: Nina.7


Signs ď Ż

Fruiting Structures:


Signs ď Ż

Non-Living


Symptoms 

Wilt


Symptoms ď Ż

Vascular Blockage


Symptoms 

Abnormal Patterns •Early Leaf Drop •No Trunk Taper

•Drought Appearance yet Turf Green •Frost Cracks Common…on Every Side


Other Symptoms     

 

Chlorosis Stunt Scorch Flat Stem Lean Witches’ Broom Die-Back


Damage    

Critters Insects String Trimmers Mowers


4. When/Where Did You Notice It?     

Spring Only? After a Maintenance Task? After a Construction Activity? Interior of the Tree? Tips of the Tree?


When/Where Did You Notice It? Patterns?: •4 maples in lawn. •Tree is changing from chlorotic to red. •It’s July.

•Lawn is lush.


5. What Caused It?  

Abiotic Causal Agent Biotic Causal Agent


Abiotic Causal Agents (75%)  

Chronic Drought Soil Problems: 

 

 

pH Drainage Compaction

Seasonal Extremes Chemical Pollution


Causal Agent: pH Extremes


Causal Agent: Late Frost


Causal Agent: Biotic (25%)     

 

Fungal Bacterial Mycoplasma Phytoplasma-like-organisms Viruses Insects &%%$*###-Deer


Biotic Causal Agent: Fungal


Biotic Causal Agent: Critters


Biotic Causal Agent: Insects


6. What if You Don’t Know? It’s a Physiological Disorder Compounded by Eriophyid Mites…and Lawn Care Companies…and Imprelis


If You Don’t Know     

Collect Symptomatic Samples for Testing Conduct Soil Tests Research Weather History Research Maintenance History Continue to Monitor For Pete’s Sake…Don’t Fertilize!

Diagnosing Tree Problems  

Diagnosing Tree Problems