The RRIV 4 rubber variety once stood out for having the highest dry rubber content among all existing rubber clones in Vietnam. Despite its impressive latex yield, RRIV 4 has shown several serious disadvantages—fragile trunk structure, high susceptibility to Corynespora leaf fall disease, and low timber volume—which have led to its discontinuation in official planting recommendations.
1. Introduction
Table of Contents
RRIV 4 was developed by the Vietnam Rubber Research Institute (RRIV) and, for a time, was widely recommended for planting in the Southeast region.
It was praised for its exceptional latex productivity and high dry rubber content, but over time, the clone revealed several major weaknesses and was eventually removed from the list of officially approved clones.
For more insights, you can read our related article: How to Choose Rubber Clones with Both High Latex and Timber Yields.
2. Origin
RRIV 4 is a domestically bred hybrid developed by the Vietnam Rubber Research Institute and was officially recognized for large-scale production in 1997.
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Initially classified under Group II (to cover 30% of the total plantation area) in the 1998–2000 Rubber Clone Structure.
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Later promoted to Group I, becoming one of the most widely planted clones in provinces such as Bình Dương, Đồng Nai, and Tây Ninh in the Southeast region.
3. Key Characteristics of RRIV 4
a. Growth and Morphology
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Strong growth during the immature period (establishment stage).
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Weaker performance during the tapping period.
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Smooth, thin, and light-colored bark with high branching height and sparse canopy.
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Slender trunk, poor wind resistance, and high breakage risk.
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Low timber accumulation at the end of the tapping cycle.
b. Latex Yield and Quality
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RRIV 4 is among the top latex-yielding clones with very high dry rubber content.
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Early latex production: Yields may reach 2 tons/ha/year as early as the third tapping year.
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Low stimulant response: The clone reacts poorly to latex stimulants (e.g., Ethephon), with minimal yield increase upon application.
c. Disease Susceptibility
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Highly susceptible to Corynespora leaf fall disease — considered a “disease indicator” clone.
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Mildly susceptible to Pink Disease.
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Moderately susceptible to Powdery Mildew.
4. Recommended Planting Regions
Although RRIV 4 is no longer included in the national recommended clone list, many plantations of this variety remain in the Southeast region, where it was historically dominant.
Some smallholders still cultivate or seek RRIV 4 seedlings because of its high latex content and early yield.
However, GCS strongly advises growers to switch to newer, improved clones under the 2016–2020 Rubber Clone Structure, ensuring better disease resistance, structural strength, and long-term productivity.
Recommended replacement clones:
RRIV 209
RRIV 106
These clones have proven stable yield performance and superior adaptability for replanting programs in the Southeast region.
5. Visual Reference
RRIV 4 Rubber Variety in Propagation Nursery
(Image: RRIV 4 seedling and field clone characteristics — light-colored bark, sparse canopy, early growth vigor.)
6. Conclusion
While RRIV 4 offers exceptionally high latex yield and dry rubber content, its major structural and pathological weaknesses—notably fragility and severe Corynespora susceptibility—make it unsuitable for future planting programs.
Plantations with RRIV 4 often suffer from defoliation (“bare branches”), resulting in low yield stability and shorter economic lifespan.
Therefore, growers are encouraged to transition to modern RRIV clones like RRIV 209 or RRIV 106, which combine high yield potential, strong trunk structure, and improved disease resistance for sustainable and efficient rubber production.