Divisi
Coffee berry disease
Colletotrichum kahawae · Fungal
Photo: Forest and Kim Starr, Starr Environmental, Bugwood.org · CC BY 3.0
Coffee berry disease (CBD) is an aggressive anthracnose fungus (Colletotrichum kahawae — a fungus that makes dark, sunken, rotting spots) that attacks Arabica coffee in Africa's cool, wet highlands. It rots the green, growing berries — and the flowers before them — turning them into hard black "mummies" that cling to the branch. Every rain splashes fresh spores from those spots onto healthy berries, so one wet, unprotected season on a variety that is not resistant can strip most of the crop.
L. Shyamal · CC BY-SA 3.0 
L. Shyamal · CC BY-SA 3.0
Why it matters
Coffee berry disease attacks the green berries you are counting on to ripen and sell. In a cool, wet year on a variety that is not resistant, it can rot up to 80% of your crop — four berries in every five — before they ever ripen. It is hard to stop once it starts, because every shower splashes its spores from the spotted berries onto clean ones, and the fungus hides through the dry season on old black "mummy" berries, bark and young wood, ready to strike again the moment the rains return. That is why protecting the berries early — before and during the wet berry-growing months — matters far more than reacting once the branches are already covered in spots.
When to act
First dark sunken lesions appearing on green (expanding) berries during wet weather at high altitude.
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 coffee berry disease field guide
- Identify it
- Scout for it
- Control it
15 field-guide sections in the app
The full guide to coffee berry disease — 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 coffee berry disease?
The first thing you see: small dark brown to black spots on the GREEN berries — not on the ripe red ones. Each spot is sunken, as if pressed in with a thumbnail, and it grows until the whole berry rots, blackens and dries hard.
When should I take action against coffee berry disease?
First dark sunken lesions appearing on green (expanding) berries during wet weather at high altitude.
How do I control coffee berry disease?
Prevent it — plant a resistant variety (your strongest tool by far): on wet, high-altitude land, grow a resistant Arabica variety such as Ruiru 11 or Batian wherever you can get the seedlings. A resistant variety shrugs off most of the disease on its own — far more reliably than any spray — and it is the one change that pays off every single wet year.
Which crops does coffee berry disease affect?
Among the crops covered here: Arabica coffee.
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.
Check what grows on your farm