Divisi
Black Sigatoka
Pseudocercospora fijiensis · Fungal
Photo: Dr. Scott Nelson · CC0
Black Sigatoka (Pseudocercospora fijiensis) is the most damaging leaf disease of banana and plantain. It is a fungus that lands on the youngest leaves and eats away the green, working leaf as fast as the plant can grow it — spreading on the wind and in splashing rain, thriving in warm, wet, crowded plantings. Once it takes hold it is very hard to stop, so the whole fight is about keeping the youngest leaves clean and the canopy dry.
Plant pests and diseases · CC0 
Plant pests and diseases · CC0
Why it matters
Your banana plant feeds its bunch with its leaves. Black Sigatoka kills those leaves from the youngest down, and a bad attack can cost you up to half your bunch (50%) — smaller hands, thinner fingers, and fruit that ripens too early and unevenly, so it spoils before it reaches the market. Once the black spots cover a leaf they cannot be cured, and the wind and rain carry the fungus's dust-like spores to every plant in the stand. That is why you must catch it while it is still faint streaks on the young leaves — waiting until the leaves turn black is waiting too long.
When to act
Act when early streaks appear on the youngest leaves or when leaf-spotting climbs the plant during wet weather.
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 black sigatoka field guide
- Identify it
- Scout for it
- Control it
16 field-guide sections in the app
The full guide to black sigatoka — 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 black sigatoka?
The first sign — look underneath: turn over the youngest open leaves and look for fine rusty, reddish-brown streaks as thin as a pencil line, running the same way as the veins. They show on the lower (under) side first, usually near the leaf tip and along one half of the leaf. This is the stage you want to catch.
When should I take action against black sigatoka?
Act when early streaks appear on the youngest leaves or when leaf-spotting climbs the plant during wet weather.
How do I control black sigatoka?
Prevent — plant a variety it struggles to beat: where your market will take them, grow tolerant or resistant banana/plantain hybrids (a variety the fungus attacks far less). This is your strongest long-term shield and it costs you no spraying.
Which crops does black sigatoka affect?
Among the crops covered here: Banana & plantain.
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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