The Leaf Tip Blight disease, alongside Corynespora Leaf Fall, is one of the most severe and destructive foliar diseases affecting rubber trees in Vietnam. It causes serious damage to the leaves during all growth stages and must be identified and managed promptly to minimize yield loss.
Symptoms and Identification
Table of Contents
Leaf Tip Blight on rubber trees is caused by the fungus Colletotrichum gloeosporioides (Penz.) Sacc., belonging to the Glomerellaceae family.
It is also known by several synonymous names such as C. acutatum Sim. ex Sim., C. ficus Koorders, C. heveae Petch, C. derridis van Hoof., and Gloeosporium alborubrum Petch.
This disease typically occurs during the rainy season (June–October) and primarily affects nurseries, budwood gardens, and immature plantations (1–2 years old)—especially in Vietnam’s Central Highlands and Central Regions.
Fortunately, because it arises after leaf canopy stabilization, it has limited impact on mature tapping trees.
Typical Symptoms
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The most susceptible stage is when leaves are 1–10 days old.
The first lesions appear as light brown spots at the leaf tip, which then expand into dark, necrotic patches, leading to progressive leaflet drop. Eventually, the entire petiole may fall off. -
Leaves older than 14 days do not drop but develop raised circular lesions containing fungal spores — locally known as “crab-eye spots.”
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The fungus may also attack young shoots and fruits, causing brown to dark-brown lesions, shoot dieback, and fruit drying.
Highly susceptible clones:
RRIM 600, GT 1, PB 255, PB 260, RRIV 1, RRIV 3, RRIV 4.
Prevention and Control Measures
1. Cultural Practices
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Maintain clean and weed-free plantations to reduce humidity and eliminate potential fungal hosts.
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Improve airflow and drainage in nurseries and young plantations.
2. Chemical Control
Apply fungicides only in nurseries, budwood gardens, and immature plantations (1–2 years old) when about 10% of the trees have young leaves emerging (“bird’s foot” stage).
Stop spraying once 80% of trees have fully developed leaf canopies.
Spray every 7–10 days in the morning with low wind.
Recommended fungicides and concentrations:
| Fungicide Type | Example Products | Concentration |
|---|---|---|
| Carbendazim | Vicarben 50SC, Carbenzim 500FL, Carbenvil 50SC, Glory 50SC | 0.2% |
| Hexaconazole | Anvil 5SC, Hexin 5SC, Vivil 5SC, Saizole 5SC | 0.2% |
| Carbendazim + Hexaconazole | Arivit 250SC, Vixazol 275SC | 0.2% |
| Carbendazim + Mancozeb | CaMa 750WP | 0.2% |
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Mix with sticking agent BDNH 2000 at 0.2% concentration to increase adhesion and effectiveness.
Conclusion
Leaf Tip Blight caused by Colletotrichum gloeosporioides is a major fungal disease of rubber trees, particularly during the rainy season.
Timely detection, proper sanitation, and correct fungicide application are essential to protect leaf integrity, prevent defoliation, and maintain high latex yield.
Growers in Vietnam’s Central Highlands and Central Regions should implement regular monitoring and follow the recommended spraying schedule to prevent widespread outbreaks.