Core sampling is a non-destructive way to check resin formation inside the tree. It allows farmers to assess color, density, and resin content without cutting the tree.
1. What Is Core Sampling?
- Definition: Removing a small cylindrical piece of wood from the trunk or branch using a coring tool.
- Purpose:
- Check resin zone development
- Monitor polymerization, color, and density
- Decide harvesting time or next induction
Think of it as a “peek inside” the tree.
2. Tools Needed
| Tool | Use |
|---|---|
| Increment borer / hand corer | Extract core sample without damaging the tree much |
| Protective gloves & sanitizer | Prevent contamination |
| Knife / scalpel | Optional trimming of core for inspection |
| Storage container | Keep sample safe for lab or field observation |
3. How Core Sampling Works
- Select a representative wound or resin zone
- Drill with an increment borer perpendicular to the trunk
- Remove a 2–5 cm long core
- Observe color, resin streaks, and wood density
- Return core if minimal, or take a small portion for lab testing
- Seal the hole with clay, wax, or stopper to prevent infection
4. What Farmers Can Observe
| Feature | Early Stage | Mid Stage | Late Stage |
|---|---|---|---|
| Color | Light yellow | Medium brown | Dark brown / black |
| Density | Soft | Firm | Dense resin zones |
| Aroma | Faint | Noticeable | Strong, complex |
| Resin streaks | Thin | Medium | Thick, continuous |
5. Practical Tips
✔ Core only healthy trees
✔ Limit sampling frequency to avoid excessive stress
✔ Record tree ID, location of core, and stage
✔ Combine with 3-, 6-, 12-month benchmarks to track resin development
✔ Use observations to plan next induction or harvesting
Farmer Key Message
“Core sampling lets you see inside the tree without harming it.
Color, density, and streaks tell you how well the resin formed.”