RUBBER NEWS

Establishing and Managing a “Core Tum” Rubber Nursery

Posted on by content02.vinahugo
13
Oct

A comprehensive technical guide on establishing and managing “core tum” rubber nurseries in Vietnam — covering site selection, nursery design, planting layout, fertilization, and preparation of mature planting stock for field use.

1. Planting Season, Site Selection, and Nursery Design

  • Planting season: Budded stumps are planted in polybags from June to August.

  • Site requirements: Choose areas with a suitable climate, available irrigation water, and convenient access for management and transport.

  • The “core tum” nursery is intercropped within first-year replanting rubber plantations to optimize land use.

  • The site must ensure good drainage, erosion resistance, and accessibility for planting, maintenance, and logistics.

Planting hole design:

  • Holes are 70 cm wide × 70 cm long × 70 cm deep, with a bottom width of 50 cm × 50 cm.

  • Spacing: 1.5 m between rows × 1.0 m between plants, arranged as three rows of seedlings between two rows of replanting rubber trees.

  • Planting density: approximately 4,500 plants per hectare.

2. Polybag and Budded Stump Specifications

  • Polybags: Use virgin PE bags (30 cm × 60 cm), with three rows of holes near the bottom and a small drainage hole at the bag base.

  • Budded stumps (tum):

    • Healthy, stable graft union and a single straight taproot.

    • Stem diameter ≤ 25 mm, root length 40–50 cm.

  • Pre-planting treatment:

    • Trim the root tip (“mouse tail”), seal the cut with vaseline, and apply rooting compound before planting into the bag.

3. Soil Preparation and Planting into Polybags

  • Soil selection: Use loamy, friable soil either from the site or transported from nearby areas. Soil should be dry to moderately moist when filling.

  • Filling process:

    • Mix fine soil with 50 g of basal fertilizer per bag.

    • Fill two-thirds of the bag, compact slightly, then top up until 1 cm below the rim.

    • Ensure bags are round and firm, not collapsed in the middle.

  • Planting technique:

    • Use a pointed stick to make a hole at the center equal to the stump’s root length.

    • Insert the stump so that the graft union sits 1 cm above the soil surface.

    • Place the bag into the planting hole so that the top of the bag is 1 cm below ground level.

4. Nursery Maintenance and Care

  • Weeding: Conduct three times per year and before each fertilization cycle.

  • Watering: Irrigate during prolonged dry spells to maintain soil moisture.

  • Pruning and pest management:

    • Regularly remove wild or lateral shoots.

    • Inspect and treat pest or disease symptoms promptly using approved agrochemicals.

5. Fertilization for “Core Tum” Rubber Nurseries

  • Fertilizer type: Use NPK 16-16-8 at a rate of 100 g per bag per year, divided into three equal applicationsevery two months.

  • Application method:

    • Drill a 3 cm-deep hole near the bag wall, apply fertilizer, and avoid contact with the stem.

    • Water thoroughly immediately after fertilization.

    • Irrigate the bags the day before each fertilizer application.

  • Foliar feeding:

    • Apply foliar fertilizers every 15 days once plants reach their first leaf whorl.

    • Combine with disease-control sprays if necessary, ensuring all chemicals are compatible for mixing.

6. Preparing Mature Seedlings for Field Planting

When seedlings reach approximately 24 months of age:

  • Topping: Cut the shoot at a height of 3 meters, seal the cut with vaseline.

  • Uprooting: Use a small mechanical digger or single-bucket excavator to lift the entire bagged plant carefully.

  • Root trimming: Shorten the taproot, leaving 10 cm from the bottom of the bag.

  • Transport: Move seedlings to field sites for immediate planting, ensuring soil moisture in bags is maintained to prevent root loosening or bag breakage.

Conclusion

The “core tum” nursery model represents an efficient intercropping system that maximizes land use during rubber replanting cycles.
By integrating proper soil management, balanced nutrition, and attentive care, this approach ensures strong, disease-free, and well-rooted seedlings ready for successful field establishment.
Adhering to these technical standards supports Vietnam’s sustainable rubber replanting and productivity enhancement goals.