6.7 Increment Borers for Agarwood Resin Assessment

Increment borers are essential tools for non-destructive sampling of agarwood resin zones. They allow farmers to monitor resin formation, wood density, and quality without cutting down the tree.

1. What Is an Increment Borer?

  • Definition: A hand tool designed to extract a small cylindrical core of wood from a tree trunk or branch.
  • Purpose:
    • Inspect resin zones
    • Measure wood density and color
    • Track resin development over time

Think of it as a “wood biopsy tool” for resin monitoring.

2. How to Use an Increment Borer

  1. Select target wound or resin zone
  2. Insert borer perpendicular to trunk or branch
  3. Twist carefully to bore into wood (~2–5 cm depth)
  4. Extract core slowly to avoid breaking it
  5. Inspect core for color, resin streaks, and density
  6. Seal the hole with clay, wax, or stopper to prevent infection

3. Parts of an Increment Borer

PartFunction
Handle / T-handleProvides leverage to twist the borer
Auger / Drill bitCuts the wood and creates the core hole
Extractor / Core removal tubePulls out the wood core without breaking it
Depth markingsHelps control drilling depth (usually 2–5 cm for resin zones)

4. Advantages of Using an Increment Borer

  • Non-destructive → tree survives
  • Accurate monitoring → resin quality and development
  • Portable and easy to use in the field
  • Supports data-driven decisions → harvesting time, next induction round

5. Practical Tips for Farmers

✔ Sterilize borer before use to avoid contamination
✔ Drill moderate depth to minimize stress
✔ Limit sampling frequency per tree (e.g., once per 6–12 months)
✔ Combine observations with resin color, smell, and density
✔ Keep records: tree ID, sample location, date, resin stage

Farmer Key Message

An increment borer is your window inside the tree.
It tells you how much resin formed without harming the tree.”