RUBBER NEWS

Weed Management in Vietnam’s Rubber Plantations

Posted on by content02.vinahugo
13
Oct

Effective weed management is essential for maintaining soil fertility, conserving moisture, and ensuring healthy growth in rubber plantations.
Vietnam’s rubber industry encourages an integrated approach combining chemical, mechanical, and biological methods to control weeds safely and sustainably.

1. General Regulations

  • Only weeds that hinder rubber tree growth (e.g., Imperata cylindrica, Pennisetum polystachion, Le spp.) or pose a fire hazard should be eradicated.

  • After spraying herbicides, restrict access to treated areas for 3–4 weeks to protect workers and livestock.

  • Mechanical and biological methods are encouraged to:

    • Lower production costs.

    • Protect human health and the environment.

    • Prevent soil erosion and nutrient leaching.

  • Use organic residues (grasses, intercrops, cover crops) for mulching, helping maintain soil moisture and improve fertility.

  • Promote legume cover crops and compatible ground covers to suppress weeds and enhance land use efficiency.

2. Weed Management in Rubber Nurseries

  • Primary control methods include manual or small-scale mechanical weeding.

  • Pre-emergence herbicides can be applied at appropriate stages.

Recommended Herbicide Application

  • Active ingredients:

    • Oxadiazon at 0.625 kg a.i./ha, or

    • S-metolachlor at 2.4 kg a.i./ha.

  • Dilution rate: 500 L water/ha.

Procedure

  1. Land Preparation:

    • Remove weeds and crop residues, then level the surface evenly.

  2. Application Schedule:

    • First spray: 3–5 days before seed placement or transplanting.

    • Second spray: 45–50 days after the first application.

  3. Precautions:

    • Ensure adequate soil moisture before spraying.

    • Avoid soil disturbance for at least 7 days post-application.

    • Prevent contact with young seedlings during the second spray.

3. Weed Management for Legume Cover Crops

  • Active ingredients:

    • Oxadiazon at 0.50 kg a.i./ha, or

    • S-metolachlor at 1.92 kg a.i./ha.

  • Dilution rate: 500 L water/ha.

Procedure

  • Prepare clean, level soil, free from weed residues.

  • Apply herbicide 3–5 days before sowing legume seeds.

  • Do not disturb the soil surface for at least 7 days after spraying.

4. Chemical Weed Control in Rubber Plantations

For Cogon Grass (Imperata cylindrica) and Bamboo Grass

  • Apply Glufosinate ammonium at 0.60–0.75 kg a.i./ha, diluted in 500–600 L water/ha.

Best Application Timing

  • During active vegetative growth, before flowering.

  • Spray in the morning and avoid spraying in the late afternoon.

  • Ensure 4–6 hours of dry weather after spraying for maximum effectiveness.

Precautions

  • Spray thoroughly to ensure full leaf and stem coverage.

  • Avoid contact with young bark, green shoots, or leaves of rubber trees.

Alternative Mixtures

  • Glufosinate ammonium at 0.45–0.60 kg a.i./ha, or

  • Glufosinate ammonium at 0.45 kg a.i./ha combined with Diuron at 0.50 kg a.i./ha for mixed weed control.

5. Mechanical Weed Management

For Immature Rubber (KTCB Stage)

  • Inter-row areas:

    • Use brush cutters (shoulder type) or tractor-mounted slashers.

    • Cut weeds 5–10 cm above the soil surface, 1–3 times per year.

  • Tree rows:

    • Combine mowing and plowing to bury weeds and create mulch around the base during the first two years (in flat areas).

    • From the third year onward, only mowing is required (1–3 times/year).

For Mature (Tapping) Plantations

  • Use motorized brush cutters or tractor slashers.

  • Cut weeds 5–10 cm above the ground, 1–2 times per year, depending on rainfall and weed density.

Conclusion

Weed management in rubber plantations should focus on long-term soil conservation and ecosystem balance.
By integrating chemical control, mechanical weeding, and cover cropping, rubber growers in Vietnam can reduce herbicide dependence, improve soil health, and maintain high productivity.