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!