Pink Disease is one of the most common and destructive branch and stem diseases affecting rubber trees (Hevea brasiliensis). It causes significant losses in both immature plantations (KTCB) and mature tapping plantations.
Below is an overview of the disease’s causes, symptoms, and effective management practices.
1. Causal Agent
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The disease is caused by the fungus Corticium salmonicolor Berk. & Br.
It usually appears between June and November, peaking in July each year.
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When the air humidity reaches around 70%, fungal spores begin to germinate and infect the bark.
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Humidity levels between 90–100% create the most favorable conditions for the fungus to grow and spread rapidly.
2. Symptoms of Pink Disease
The disease gets its name from the characteristic pink color of the infected area. It typically develops in two stages:
Early Stage (Mild Infection)
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Small white patches appear on the bark, often accompanied by latex droplets.
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White fungal mycelium, resembling spider webs, spreads around the infected area.
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Under favorable weather conditions, the lesions turn light pink and continue to expand.
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The mycelium thickens, penetrates the bark, and causes heavy latex flow that later turns black due to oxidation.
Advanced Stage (Severe Infection)
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The infected bark turns deep pink.
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Leaves and branches above the infected area turn yellow, wilt, and die.
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Adventitious shoots may appear below the infected zone, while the bark cracks and peels away.
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In Vietnam, lesions can extend up to 5–7 meters along the trunk and may even affect the tapping panel.
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Once the tree’s apex is destroyed, it cannot recover, resulting in loss of latex production.
3. Disease Management and Control
Early Detection and Treatment
At the first sign of infection, promptly apply one of the following fungicides:
| Active Ingredient | Product Examples | Concentration |
|---|---|---|
| Validamycin | Validacin 5L, Vanicide 5SL | 1.0 – 2.0% |
| Hexaconazole | Anvil 5SC, Hexin 5SC, Vivil 5SC, Saizol 5SC | 0.5% |
Mix with an adhesive agent (e.g., BDNH 2000 at 1.0%) for better coverage.
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Use a knapsack sprayer with an extended nozzle to ensure complete coating of the infected area.
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Repeat every 10–14 days until the infection disappears.
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Mark treated trees and reapply if the fungus persists.
Cultural and Sanitation Practices
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Stop tapping infected or defoliated trees immediately.
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During the dry season, cut and remove dead branches and trees, burning them at the field’s edge to prevent spore spread.
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Maintain good ventilation in plantations by pruning and removing excess shoots.
4. Prevention Strategies
Because Pink Disease can severely damage the entire canopy, prevention is far more effective than treatment.
Here are essential preventive measures:
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Plant disease-resistant rubber clones recommended by the Vietnam Rubber Group (VRG).
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Spray protective fungicides during high-risk months (especially in prolonged rainy or humid weather).
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Maintain proper planting density, adequate drainage, and balanced fertilization to enhance tree vigor.
5. Conclusion
Pink Disease significantly impacts both growth in immature plantations and latex yield in mature ones.
In severe cases, it can kill trees completely, leading to major economic losses.
Therefore, preventive management—including early detection, proper fungicide use, and good plantation hygiene—is the most effective and sustainable approach.