Divisi
Stem-end rot
· Fungal
Photo: Scot Nelson from USA · CC0
Stem-end rot is a fungal rot of tree fruit (mango, avocado, citrus, papaya and banana) caused by fungi such as Lasiodiplodia, Dothiorella, Phomopsis and Colletotrichum. The fungus lives in dead wood and dieback in the tree and quietly infects the fruit stalk and button while the fruit is still on the tree. The infection then sleeps (stays latent — hidden and doing nothing you can see) until the fruit ripens, when a soft brown-black rot spreads out of the stem end into the flesh. It is above all a postharvest disease: the damage you paid for in the orchard shows up in the store, the truck and the market.
Scot Nelson · CC0
Why it matters
Stem-end rot is a thief that robs you after the hard work is done. Because the fungus sneaks in at the button while the fruit is still green and then hides, the fruit can look perfect when you pick it and pack it — then rot from the stalk end in the store, the truck or on the market table, so you can lose up to 4 in every 10 fruit (40%) after harvest. That is money already spent on growing, picking and transport, thrown away at the last step. It is hard to fix once it has taken hold because you cannot see the hidden infection to sort it out, and no spray reverses a rot that has already started — the whole fight has to be won before and during harvest, not after.
When to act
A postharvest fruit disease; act pre-emptively with orchard sanitation, careful harvest and cool handling rather than a field count, as rot appears mainly after harvest.
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 stem-end rot field guide
- Identify it
- Scout for it
- Control it
15 field-guide sections in the app
The full guide to stem-end 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 stem-end rot?
The first and clearest sign: a dark brown to black, soft, wet rot that begins right at the stem end — the button where the stalk joined the fruit — and spreads out from there like a stain into the sound flesh. Press it and it gives way, mushy and watery, not firm. This almost always shows up as the fruit ripens in the store, the crate or on the way to market, not on the tree.
When should I take action against stem-end rot?
A postharvest fruit disease; act pre-emptively with orchard sanitation, careful harvest and cool handling rather than a field count, as rot appears mainly after harvest.
How do I control stem-end rot?
Prevent first — clean up the tree (your strongest non-chemical tool): prune out all dead wood, dead branch tips and dieback and carry it away from the orchard, and keep trees healthy and unstressed. This is the single best lever because it removes where the fungus lives and breeds, lowering the inoculum (the fungus's "seed" — the spores that start new infections) before it ever reaches the fruit.
Which crops does stem-end rot affect?
Among the crops covered here: Avocado, Mango, Papaya.
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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