Coffee berry disease (CBD)
A fungus that rots green and ripening cherries from the outside in, worst on Arabica at higher, cooler elevations — and one of the most costly diseases a coffee grower can face.
- Pathogen
- Fungus (Colletotrichum kahawae)
- Favoured by
- Cool, wet weather; high elevation
- Hardest hit
- Arabica (more than Robusta)
- Potential loss
- Half the crop or more if unmanaged
Overview
Coffee berry disease (CBD) is caused by a fungus, Colletotrichum kahawae, that infects coffee cherries while they are still green or just starting to ripen — unlike many fruit rots that only strike fully ripe fruit. It makes sunken, dark lesions on the cherry that spread and rot the berry from the outside in, often destroying it before the bean inside has even fully formed, so the loss is a whole berry, not just a blemish.
The fungus is favoured by cool, wet weather and is worst at higher elevation, and it attacks Arabica far harder than Robusta. Left unmanaged in a bad, wet year, CBD can cut a crop by half or more, which makes it one of the costliest diseases a coffee grower can face. Because the disease can build up fast once wet, flowering-to-berry-set weather sets in, management depends on a properly timed spray programme, not on reacting once damage is already visible.
How to identify it
- Sunken, dark, anthracnose-like lesions on green and ripening cherries — not just on fully ripe fruit.
- Lesions spread and rot the berry from the outside in, often before the bean inside has fully formed.
- Heavily affected berries shrivel, blacken and fall, or stay attached as dried, useless mummified cherries.
- Symptoms are worst at higher elevation and in a cool, wet season, and worst on Arabica blocks.
What causes it and when
- A fungus, Colletotrichum kahawae, that infects green and ripening cherries directly, unlike diseases that only attack fully ripe fruit.
- Cool, wet weather, especially at higher elevation, strongly favours the fungus and lets it spread fast.
- The riskiest window is from flowering through berry set and early development, when cherries are green and most vulnerable.
- Arabica is far more susceptible than Robusta, so Arabica blocks at higher, cooler elevation carry the highest risk.
Cultural & organic control
- Plant CBD-tolerant selections such as Cauvery or Catimor on high-risk, high-altitude blocks where the disease has been a recurring problem.
- Keep the canopy open enough for good air movement, since a dense, stagnant canopy stays wet for longer and favours the fungus.
- Remove and destroy mummified, disease-killed berries left on the plant, since they can carry the fungus into the next season.
- Maintain good general plant nutrition, since a vigorous bush tolerates disease pressure better than a stressed one.
Chemical control
- Run a scheduled protectant and curative fungicide programme — typically copper-based sprays combined with a systemic fungicide — timed to the wet flowering-to-berry-set window.
- Start spraying before symptoms appear, not after, since the disease can spread fast once wet weather sets in and existing lesions cannot be cured.
- Repeat sprays through the risk period as advised, since a single early spray is not enough to cover the whole vulnerable window.
- Confirm the current recommended fungicide programme, products and timing for your area and elevation with your local Krishi Vigyan Kendra (KVK) or coffee board extension service.
Prevent it coming back
- On blocks with a history of CBD, plan the spray programme every season around the flowering-to-berry-set window rather than waiting to see if the disease appears.
- Favour CBD-tolerant selections on new plantings at high-risk, high-altitude sites.
- Keep the canopy well-managed for airflow and remove mummified berries each season so the fungus has less carried-over material to restart from.
Crops most at risk
Where this problem is called out in our crop guides — open a crop for the full package of practices.
Frequently asked questions
How is coffee berry disease different from an ordinary fruit rot?
Most fruit rots only attack fruit that is fully ripe or already damaged, but coffee berry disease infects cherries while they are still green, often before the bean inside has even fully formed. That is why waiting until berries look ripe to start protecting them is too late — the spray programme has to be timed to the flowering-to-berry-set window, before the fungus gets in.
Why does this disease hit Arabica so much harder than Robusta?
Arabica is genetically far more susceptible to Colletotrichum kahawae than Robusta, and Arabica is also typically grown at the higher, cooler elevations that favour the fungus in the first place — so the crop most exposed to the right weather is also the more vulnerable species. This is why CBD-tolerant Arabica selections such as Cauvery or Catimor matter especially on high-altitude Arabica blocks.
Can I wait to spray until I see lesions on the cherries?
No — by the time lesions are visible, the berries already affected cannot be cured, and the fungus can spread very fast through the rest of the block in wet weather. The scheduled protectant and curative spray programme needs to start before symptoms appear, timed to the wet flowering-to-berry-set window, not as a reaction once damage is already visible.
Symptoms and control measures follow ICAR, KVK and state agricultural-university package-of-practices; any named chemical is a registered use. Always read the product label and confirm the dose for your crop and zone. editorial policy.