Divisi
Brown eye spot
Cercospora coffeicola · Fungal
Photo: Scot Nelson · CC0
Brown eye spot (Cercospora coffeicola) is the most common fungal disease of coffee, attacking both the leaves and the berries. Its dust-like spores spread by rain-splash and wind, and infection takes hold when leaves stay wet for a long time and the plant is stressed by poor feeding, drought or too much direct sun. On leaves it forms round, yellow-ringed 'eye' spots that make the leaves drop; on berries it leaves sunken brown blotches that ripen unevenly and downgrade the cherry. Because it is driven by plant stress, it is beaten by keeping the bush well-fed, shaded and watered far more than by spraying alone.
Ernani Zimmermann · CC BY-SA 4.0 
Ernani Zimmermann · CC BY-SA 4.0
Why it matters
Brown eye spot is the most common disease of coffee, and it hurts you twice: on the leaves it makes them yellow and drop, weakening the bush so it carries fewer, smaller cherries, and on the berries it leaves sunken brown blotches that ripen early, fall before harvest, and fetch a lower price. Together that can cost you up to a third (30%) of your crop. The hard part is that the disease is really a sign your plants are stressed — hungry, sun-baked or thirsty — so you cannot simply spray it away: copper only coats the leaf to stop new spots, and can never cure a spot or bring back a leaf that has already dropped. Unless you fix the underlying stress, it comes back every wet season.
When to act
first eye-spots on leaves of nursery seedlings or on developing berries
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 brown eye spot field guide
- Identify it
- Scout for it
- Control it
11 field-guide sections in the app
The full guide to brown eye spot — 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 brown eye spot?
The eye-spots (the giveaway): round brown spots on the leaves, each with a pale grey, tan or almost-white centre ringed by a bright yellow halo — like a small eye or a bird's eye staring back at you. They begin as tiny brown pinpricks and grow to the size of a pea or a small fingernail (up to about 1 cm across), and the dry centre may crack or fall out, leaving a little hole.
When should I take action against brown eye spot?
first eye-spots on leaves of nursery seedlings or on developing berries
How do I control brown eye spot?
Prevent it — feed and shade the plant (your strongest tool): brown eye spot is a stress disease, so a well-fed, well-shaded bush largely shrugs it off. Give balanced feeding with enough nitrogen (manure, compost or a nitrogen fertiliser) so the leaves stay green and strong; provide shade over exposed plants and nurseries; and avoid water stress in dry spells. Start with clean, disease-free nursery stock so you are not planting the problem.
Which crops does brown eye spot affect?
Among the crops covered here: Robusta 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.
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