Divisi
Butt rot
Ganoderma spp. · Fungal
Photo: Vengolis · CC BY-SA 4.0
Butt rot (also called basal stem rot) is a fungal decay of the base of oil palm and coconut trunks, caused by the wood-rotting fungus Ganoderma. It rots the woody base and root plate from the inside, creeping from palm to palm where their roots touch underground and living on for years in old stumps and roots left in the ground. It is worst on land replanted with palms a second or third time, and it is a killer — there is no cure once a palm is infected; the base finally gives way and the palm topples.
Bob Peterson · CC BY-SA 2.0 
Edward L. Barnard · CC BY 3.0 us
Why it matters
Butt rot is a palm killer. On bad land — especially where old, infected palms were cleared before — it can rot and topple up to 4 out of every 5 of your palms (80%), and a palm takes years of care to reach bearing, so every one you lose is years of work and income gone. It is so hard to beat because it hides at the base and in the roots where no spray can reach, and it creeps underground from one palm to the next and out of buried old stumps. By the time you see the woody bracket at the base or the skirt of dead fronds, that palm is already lost — which is why keeping it OUT with clean replanting and strong palms matters far more than trying to cure it.
When to act
any palm with skirting of unopened fronds or basal bracket fungi
This guidance is general, compiled from published agronomic references including FAO and CABI. Thresholds and timing shift with your crop, your variety and the season.
In much of the region a spray is simply called mushonga — medicine. But a chemical group you cannot name is one you cannot rotate, and a product you did not write down has no pre-harvest interval you can observe. Mushonga, and other farming words →
The full butt rot field guide
- Identify it
- Scout for it
- Control it
14 field-guide sections in the app
The full guide to butt rot — every symptom to check, how and when to walk your field looking for it, and the controls that actually work, ranked. Built into your crop plan, so you are told to look before it costs you a harvest.
Crops it affects
Frequently asked questions
How do I identify butt rot?
The first thing you notice is the crown. The oldest, lowest fronds turn pale and yellow, dry to brown, and hang straight down against the trunk like a skirt instead of dropping off. At the same time the youngest spear leaves (the new fronds before they open) pile up unopened in the middle, and the whole crown looks pale, flattened and one-sided — the palm is starving because its rotten base can no longer feed it.
When should I take action against butt rot?
any palm with skirting of unopened fronds or basal bracket fungi
How do I control butt rot?
Prevent it — clean the land before you replant. The fungus lives on for years in old palm stumps and roots, so before you plant a new palm crop, dig out and burn or destroy every old stump and big root from the palms that stood there before. Never plant a young palm straight into ground still full of old infected debris — that is how most new plantings catch the rot. This clean-up is your single most powerful defence.
Which crops does butt rot affect?
Among the crops covered here: Coconut, Oil palm.
Catch it before it costs you a harvest
Divisi builds scouting into your crop plan — it tells you when to walk your field, what to look for at that stage, and what to do when you find it. Free for farmers, works offline.
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