> ## 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.

# Diagnose and Respond to Upper Stem Rot in Oil Palm

> Identify Upper Stem Rot from Ganoderma-type brackets appearing on the mid-trunk rather than at the base, and manage it with the same census, sanitation, and resistance program used for basal Ganoderma.

Upper Stem Rot is caused by *Ganoderma zonatum* and related *Ganoderma* species. It is a variant of the basal-stem-rot disease, but the fruiting bodies appear on the *mid-trunk* rather than at ground level. It is often overlooked at census because scouts trained to look at the base miss brackets 1 to 3 metres up. In blocks with mixed Ganoderma pressure, both forms need to be recorded together.

**Regional priority:** Same regions as basal Ganoderma. In practice, most Ganoderma monitoring programs treat basal and upper stem rot as one disease with two symptom locations.

## When oil palm is most vulnerable

Stand age matters as much as with basal Ganoderma. Upper Stem Rot is more common on older palms (10+ years) and on palms with previous trunk wounds from pruning, harvesting, or lightning strikes.

## How Upper Stem Rot shows in satellite data

* **Individual-palm decline** with the same crown signatures as basal Ganoderma - one-sided collapse, hanging fronds, standing spear.
* **Not distinguishable from basal Ganoderma in imagery** at typical resolutions. The distinction is made on the ground.
* Same block-level and cluster-level alert logic as basal Ganoderma.

<Warning>
  Scouts trained only on basal brackets miss Upper Stem Rot. Always look up the trunk to a full palm-height during census, not just at the base.
</Warning>

## Field symptoms

* **Mid-trunk brackets** - the same shelf-shaped fruiting bodies as basal Ganoderma, but 1 to 3 metres up the trunk (occasionally higher).
* **Fronds above the infection line collapse** while lower fronds and the base may still look healthy - the mirror image of the basal-Ganoderma pattern.
* **Trunk breakage** at the infection line during storms - a late-stage indicator.
* **Sap oozing** from old wounds where the fungus entered.
* Same reduced bunch load and eventual palm death as basal Ganoderma.

## Reduce the damage by

Upper Stem Rot uses the same management program as basal Ganoderma. See [Ganoderma (BSR)](/guides/Crop/Oil-Palm/biotic/diseases/ganoderma) for the full program. Additions specific to Upper Stem Rot:

* **Avoid trunk wounds** - most Upper Stem Rot infections start at old pruning or harvest wounds. Train harvesters to cut petioles cleanly and not to chip the trunk.
* **Do not stack cut fronds against the trunk** - decaying frond bases against a living trunk create infection sites.
* **Sanitize pruning tools** - clean cutting tools between palms in high-pressure blocks.
* **Report separately from basal Ganoderma** at census, but treat under the same sanitation and replanting program.

## Set an alert for early warning

<Tip>
  Turn the diagnosis into a trigger. Roll Upper Stem Rot into the same Ganoderma census - a single visit to each palm records both forms.
</Tip>

Recommended settings for Upper Stem Rot on oil palm:

* **Quarterly census reminder** - same schedule as basal Ganoderma. Record trunk-inspection separately for base and mid-trunk.
* **Palm-cluster NDVI drop alert** - same as basal Ganoderma. The satellite cannot distinguish the two.
* **High-resolution imagery review** twice per year on stands over 10 years old.

## Related

* [Oil Palm Diagnosis](/guides/Crop/Oil-Palm/oil-palm-diagnosis)
* [Ganoderma (BSR)](/guides/Crop/Oil-Palm/biotic/diseases/ganoderma) - the primary management program applies to both forms.
* [Field Walk Protocol](/guides/Crop/Oil-Palm/field-walk-protocol)
* [Set up automated crop alerts](/guides/alerts-notifications)