> ## Documentation Index
> Fetch the complete documentation index at: https://badixth-dc85e378.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Brown Root Disease in Rubber

> Phellinus noxius: the third major root disease in Malaysian rubber. Slower spread than white or red root but persistent in old estate blocks. Recognition and destroy protocol.

**Brown root disease** (*Phellinus noxius*) is the third of Malaysia's three major rubber root diseases. It is less common than white or red root but persists in old estate blocks and re-emerges at replanting. Slower spread but similar cordon-and-destroy management.

## Cause

* **Old stumps** in replanting blocks
* **Long-cycle estates** with multiple rubber rotations
* **Adjacent forest edges**

## Effect

| Stage | Above-ground symptom            | Below-ground symptom                                                      |
| ----- | ------------------------------- | ------------------------------------------------------------------------- |
| Early | None visible                    | Dark brown crust with soil particles firmly encrusted on the root surface |
| Mid   | Yellowing, thinning canopy      | Crust thickens, root rot                                                  |
| Late  | Wilting, latex drop, tree death | Roots destroyed                                                           |

The key diagnostic is the **soil-encrusted crust** on the roots that resists brushing off.

## Satellite signals

Same expanding-cluster pattern as white and red root, but slower (0.3 to 0.5 m/year).

## Action

<Steps>
  <Step title="Confirm at the collar">
    Dark brown crust with adhering soil that cannot be brushed off confirms *Phellinus noxius*.
  </Step>

  <Step title="Cordon and destroy">
    Same protocol as [white root](/guides/Crop/Rubber/biotic/diseases/white-root).
  </Step>

  <Step title="Follow up">
    3-month cadence for 2 years.
  </Step>
</Steps>

## Recommended alert settings

Same as [white root](/guides/Crop/Rubber/biotic/diseases/white-root).

## Related

* [White root disease](/guides/Crop/Rubber/biotic/diseases/white-root)
* [Red root disease](/guides/Crop/Rubber/biotic/diseases/red-root)
* [Field Walk Protocol](/guides/Crop/Rubber/field-walk-protocol)