7.2 Tracking resin quantity and chemical profile

1. Why Track Resin

  • Resin quantity determines harvest yield and profitability
  • Chemical profile determines aroma quality and oil grade
  • Helps assess inoculation success (BarIno system)
  • Guides timing for harvest or follow-up inoculation

2. Tracking Resin Quantity

A. Visual Observation

  • Look for darkening around inoculation points
  • Small resin exudates or droplets on trunk indicate active resin formation
  • Track number and size of resin zones over time

B. Physical Sampling

  • Non-destructive scraping or drilling around inoculation points
  • Weigh small chips or shavings to estimate resin accumulation per tree
  • Record date, tree ID, inoculant type, and weight

C. Tree Scoring System

  • Simple scoring (1–5) for resin coverage:
ScoreResin Formation
5Large, dense veins around all inoculation points
4Moderate veins, multiple points active
3Small veins, limited points
2Minimal resin, single point
1No resin visible

3. Tracking Chemical Profile

A. Purpose

  • Determines aroma complexity (sesquiterpenes, chromones)
  • Guides grading for oud oil quality

B. Methods

  1. Field-level indicators (farmer-friendly)
    • Darker wood → higher resin concentration
    • Rich smell when scraping → aromatic compounds developing
    • Compare samples to known reference trees
  2. Laboratory-level analysis
    • GC-MS (Gas Chromatography–Mass Spectrometry)
      • Identifies specific sesquiterpenes and chromones
      • Confirms oil-grade quality
    • Thin-layer chromatography (TLC) or NIR for preliminary screening

4. Sampling Best Practices

  • Take small, representative chips from different inoculation points
  • Avoid weakening the tree; do not over-sample
  • Label samples: Tree ID, inoculation type, date, location

5. Monitoring Schedule

  • Weekly visual checks for resin exudation
  • Monthly chip sampling for weight/quantity
  • Every 3–6 months for chemical analysis in labs (optional, if targeting premium oil)

6. Farmer-Friendly Summary

“Track how much resin forms and how aromatic it smells. Small chips tell the story: darker, aromatic resin means better yield and oil quality.”