Cause
- Over-tapping (frequency higher than tree can sustain, e.g. d/1 continuously)
- Excessive stimulation (over-use of ethephon)
- High-yielding susceptible clones (RRIM 600, some RRIM 2000 series)
- Nutrient imbalance, especially K deficiency
- Environmental stress (drought, prolonged haze, waterlogging)
- Poor tapping technique (deep cuts, bark damage)
Effect
Field signs:
- Cut goes dry within days or weeks
- Latex color grey or watery before drying up
- Bark below the cut shows brown discoloration on scraping
- Tree canopy remains healthy (distinguishes TPD from disease)
Satellite signals
Block-scale TPD (> 10% of trees affected) shows as:Action
1
Confirm individual trees
Test-tap: fresh short cut above the panel. If fresh latex flows normally, the panel below is TPD-affected.
2
Rest the panel
Stop tapping the affected panel for 3 to 6 months. In many cases, latex flow returns after rest.
3
Reduce tapping intensity block-wide
Switch the whole block from d/2 to d/3 or d/4 if TPD incidence exceeds 5%. Continued heavy tapping compounds the problem.
4
Correct K deficiency
Test Whorl 2 K. Apply corrective KCl per the potassium page.
5
Reduce stimulation
Suspend ethephon for at least 6 months on TPD-prone blocks. If restarting, use low concentration and long intervals.
6
Retrain tappers
Bad cutting technique (deep, ragged, over-consumed panels) drives TPD incidence. Refresh training annually.
7
Long-term: replant with tolerant clones
Chronic TPD blocks (> 20% incidence) are candidates for replanting with more tolerant clones.