Rubber Plus: A heavily skewed Nitrogen (N) and Potassium (K). Nitrogen fuels the regeneration of the bark and vegetative biomass, while Potassium directly regulates cell turgor pressure, maintaining continuous latex flow and high Dry Rubber Content (DRC) without plugging the latex vessels
• Apply Rubber Plus when the soil has adequate moisture and is not waterlogged.
• Do not place fertilizer directly against the trunk or stem of the rubber tree.
• Distribute the material uniformly in the active root zone rather than concentrating it at one point.
• As the trees grow, move the application area progressively away from the trunk and toward the canopy/root zone.
• For mature plantations after canopy closure, application can be made in patches between four trees, followed by light forking/incorporation into the surface soil.
• Avoid applying a large dose immediately before heavy rainfall.
• Where drainage is poor, correct drainage before increasing fertilizer application.
• Application method is based on the assumption of 170/trees per acre.
The following ranges are intended as starting points for field demonstration and agronomic evaluation. They should be refined after confirming the product's guaranteed analysis.
| Rubber stage | Rubber Plus/tree/year | kg/acre/year | 50-kg bags/acre | Suggested splits |
|---|---|---|---|---|
| 0–3 months | 0–100 g | 0–17 kg | 0–0.34 | Avoid concentrated application around young plants |
| 3–12 months | 300–400 g | 51–68 kg | 1.02–1.36 | 2–3 |
| 1–2 years | 500–700 g | 85–119 kg | 1.70–2.38 | 2–3 |
| 2–3 years | 700–900 g | 119–153 kg | 2.38–3.06 | 2–3 |
| 3–4 years | 800–1,000 g | 136–170 kg | 2.72–3.40 | 2–3 |
| 4–5 years / pre-tapping | 800–1,000 g | 136–170 kg | 2.72–3.40 | 2–3 |
| Mature tapping | 900–1,200 g | 153–204 kg | 3.06–4.08 | 2–3 |
| High-yielding mature block | 1,000–1,500 g | 170–255 kg | 3.40–5.10 | 3 |
Note: These quantities are provisional field-use ranges for Rubber Plus. They are not a direct gram-for- gram substitute for conventional rubber fertilizer mixtures.
| Soil type | General approach | Mature-tree starting range | Splits/year | Main precautions |
|---|---|---|---|---|
| Laterite | Split rather than increase the annual dose; maintain soil organic matter. | 1.0–1.2 kg/tree/year | 3 | Avoid heavy pre-rain application; monitor pH, K, Ca and Mg. |
| Red loam | Use the normal calculated dose; two applications are generally practical. | 0.9–1.1 kg/tree/year | 2 | Apply to moist soil; monitor P, K and organic carbon. |
| Sandy / sandy loam | Use smaller, more frequent applications because of rapid drainage and nutrient-loss risk. | 0.9–1.1 kg/tree/year | 3–4 | Avoid large doses before rain; improve organic matter where appropriate. |
| Heavy clay / clayey | Do not increase dose merely because the soil is clayey; drainage comes first. | 0.9–1.1 kg/tree/year | 2 | Never apply into waterlogged soil; avoid deep placement. |
| Soil type | 1st application | 2nd application | 3rd application | 4th application |
|---|---|---|---|---|
| Laterite | April–May | July–August | September–October | — |
| Red loam | April–May | September–October | — | — |
| Sandy / sandy loam | April–May | June–July | August | September–October |
Timing should be adjusted according to rainfall, soil moisture and local plantation conditions. Do not apply immediately before a period of very heavy rainfall.
5.1 Laterite Soil. For mature plantations, a provisional starting range is 1.0–1.2 kg/tree/year. At 170 trees/acre this equals 170–204 kg/acre/year, or approximately 3.40–4.08 bags of 50 kg.
| Time | Dose/tree | Quantity/acre |
|---|---|---|
| April–May | 400 g | 68 kg |
| July–August | 300–400 g | 51–68 kg |
| September–October | 300–400 g | 51–68 kg |
| Total | 1.0–1.2 kg | 170–204 kg |
Start closer to 1.0 kg/tree/year and increase only when supported by soil/leaf analysis and tree response.
5.2 Red Loam Soil: For mature trees, a provisional starting range is 0.9–1.1 kg/tree/year. At 170 trees/acre this equals 153–187 kg/acre/year, or approximately 3.06–3.74 bags.
| Application | Dose/tree at 1.0 kg annual rate | Quantity/acre |
|---|---|---|
| April–May | 500 g | 85 kg |
| September–October | 500 g | 85 kg |
| Total | 1.0 kg | 170 kg |
5.3 Sandy / Sandy-Loam Soil. For mature trees, a provisional starting range is 0.9–1.1 kg/tree/year. Use smaller and more frequent applications rather than two large doses.
| Application | Dose/tree at 1.0 kg annual rate | Quantity/acre |
|---|---|---|
| April–May | 250 g | 42.5 kg |
| June–July | 250 g | 42.5 kg |
| August | 250 g | 42.5 kg |
| September–October | 250 g | 42.5 kg |
| Total | 1.0 kg | 170 kg |
5.4 Heavy / Clayey Soil: For mature trees, a provisional starting range is 0.9–1.1 kg/tree/year, normally in two applications.
| Application | Dose/tree at 1.0 kg annual rate | Quantity/acre |
|---|---|---|
| April–May | 500 g | 85 kg |
| September–October | 500 g | 85 kg |
| Total | 1.0 kg | 170 kg |
If the soil remains waterlogged after rainfall, do not apply additional fertilizer until adequate drainage is restored.
5.5 Immature Rubber – Reference Benchmark: A published conventional rubber fertilizer programme provides a useful benchmark for understanding the scale of nutrient application during immature growth. It includes approximately 225 g/tree at 3 months, 450 g at 9 and 15 months, 550 g at 21 and 27 months, and 450 g at 33 and 39 months, with applications mainly in April–May and September–October after the first application. These benchmark quantities relate to conventional fertilizer mixtures and must NOT be substituted gram-for-gram with Rubber Plus.
5.6Mature Rubber – Reference Benchmark: A published benchmark gives approximately 900 g/tree/year of a 10:10:10 mixture for mature tapping rubber, equivalent to about 300 kg/ha/year in two split applications. This is approximately 121 kg/acre/year or 2.43 bags/acre of a 50-kg product. This benchmark is provided only for scale comparison. It does not mean that 2.43 bags of Rubber Plus are nutritionally equivalent to 2.43 bags of a 10:10:10 fertilizer.