The immature stage (KTCB – Kiến Thiết Cơ Bản) of rubber trees, typically the first 5–7 years after planting, determines future productivity and plantation sustainability.
Following the technical regulations of the Vietnam Rubber Group (VRG), every operation — from weed management to mulching and cover crops — is designed to protect the soil, conserve moisture, and promote healthy tree growth.
This article outlines the standard agronomic practices for rubber plantations during the KTCB phase.
1. General Cultivation Guidelines
Table of Contents
Article 65. General Regulations
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All member companies must follow the technical cultivation standards defined in VRG’s official Rubber Technical Procedures.
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Mechanization is encouraged to improve labor efficiency and reduce manual work, depending on local conditions.
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Weed control should be primarily mechanical or manual — chemical herbicides are restricted to protect the environment.
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Maintain a controlled natural ground cover (15–20 cm tall) between rows, except for Imperata cylindrica, Leucaena, bamboo, and sedge species.
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Prevent soil erosion, water runoff, and excessive evaporation through proper ground management.
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Strengthen fire prevention and supervision during the dry season.
Sustainable soil and vegetation management is central to long-term rubber productivity and environmental protection.
2. Weed Management along Tree Rows
Article 66. Weed Control within Rubber Rows
Objectives
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Prevent fire hazards during the dry season.
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Reduce weed competition for nutrients and moisture.
Requirements
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Keep areas around the rubber base clean, especially before fertilizer application (year 1–2).
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Avoid soil erosion and runoff on sloped terrain.
Implementation
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Year 1: Clear weeds within a 0.8 m radius around the tree.
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Years 2–3: Expand to a 1.0 m radius.
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Years 4–5: Maintain a 1.5 m radius around tree bases.
Methods
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Year 1: First weeding manually; second weeding may combine with mechanical soil mulching using furrow plows (1 m from the base) at the end of the rainy season.
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Year 2 onward: Combine mechanical and manual weeding; use chemical herbicides only for tough species like Imperata cylindrica, Leucaena, sedge, or bamboo.
Frequency (by Region)
| Region | Year 1 | Year 2 | Year 3 | Year 4–5 | Year ≥6 |
|---|---|---|---|---|---|
| Southeast Vietnam | 2 | 3 | 2 | 2 | 1 |
| Central Highlands | 2 | 3 | 2 | 3 | 1 |
| North Central & Coastal Vietnam | 2 | 3 | 2 | 4 | 1 |
| Cambodia & Laos | 2 | 3 | 2 | 3 | 1 |
Additional Notes
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On slopes >10°, weed in circular basins to prevent erosion.
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In lowland or flood-prone areas, mound soil around the base at least 10 cm higher than ground level to prevent waterlogging.
3. Inter-row Vegetation Management
Article 67. Weed and Grass Control between Rows
General Principles
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Control weeds in early years until the canopy closes.
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Maintain ground cover to reduce erosion, evaporation, and fire risk.
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Encourage mechanized weed cutting for efficiency.
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Preserve a natural cover of 15–20 cm between rows (excluding invasive species).
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On slopes >10°, avoid full clearing; instead, manage natural cover to prevent soil loss.
Frequency (No Intercropping)
| Region | Year 1 | Year 2 | Year 3 | Year 4–5 | Year ≥6 |
|---|---|---|---|---|---|
| Southeast Vietnam | 1 | 3 | 2 | 2 | 1 |
| Central Highlands | 1 | 3 | 2 | 3 | 1 |
| Northern Mountains & Coastal Vietnam | 1 | 3 | 2 | 3 | 1 |
| Cambodia & Laos | 1 | 3 | 2 | 3 | 1 |
For intercropped areas: skip inter-row weeding during intercrop years; resume afterward per the table above.
Labor Adjustment
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Units may adjust weeding frequency depending on actual conditions, ensuring total costs remain within VRG’s budget norms.
4. Soil Tillage Practices
Article 68. Plowing Regulations
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Avoid excessive plowing to reduce erosion, soil degradation, and root damage — especially in sandy, lateritic, or sloped soils.
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Plowing is only permitted in flat areas during the first 3 years:
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Keep furrows ≥1 m from the tree base (years 1–2) and ≥1.5 m in year 3.
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Do not plow on slopes >10° or deeper than root depth.
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After year 3, plowing is allowed only for fire prevention or soil renovation, under supervised and approved conditions.
5. Mulching and Sunburn Protection
Article 69. Mulching and Whitewashing
Mulching
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Prefer mechanical mulching; where not feasible, mulch manually:
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Use grass, leguminous cover, or intercrop residues at the end of the rainy season.
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Form a ring 1 m radius, 10 cm thick, 10 cm away from the trunk, and cover with 5 cm of soil.
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In low areas, mound soil 15–20 cm high around the tree.
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Mechanical method:
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Furrow width ≥2 m, with plow lines 1–1.5 m from the tree row depending on age.
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Conduct soil mulching at the end of the rainy season.
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Whitewashing
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In hot, dry regions, apply 5% lime solution to the lower 1 m of the trunk during the first two years to prevent sunburn.
6. Leguminous Ground Cover Establishment
Article 70. Planting Legume Cover Crops
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Encourage legume cover crops from the first year, especially in non-intercropped areas.
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Common species:
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Kudzu (Pueraria phaseoloides),
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Wild Pueraria (Pueraria triloba),
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Mucuna bracteata or Mucuna cochinchinensis.
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Planting Density
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Kudzu / Pueraria triloba: 3 rows between 2 rubber rows, spaced 1 × 1 m (4,000–5,000 holes/ha).
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Mucuna bracteata: 1 central row, plants 5–6 m apart (250–300 holes/ha).
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Use Mucuna bracteata mainly in dry or sloping regions.
Fertilization and Maintenance
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Weed and fertilize legume covers regularly for fast early growth.
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Apply phosphate fertilizer during establishment for strong root development.
Conclusion
Effective management during the immature stage of rubber cultivation is crucial for long-term yield, soil conservation, and climate resilience.
Vietnam’s VRG standards combine modern mechanization, ecological balance, and sustainability, positioning the country as a global leader in responsible rubber production.