Divisi
Bacterial wilt
Ralstonia solanacearum · Bacterial
Photo: Clemson University - USDA Cooperative Extension Slide Series, , Bugwood.org · Public domain
Bacterial wilt is a soil- and water-borne disease caused by the bacterium Ralstonia solanacearum. It slips in through the roots and plugs the plant's water pipes (the tiny tubes that carry water up the stem), so the plant suddenly flops and dies while its leaves are still green. It attacks tomato, potato, pepper, eggplant, groundnut and banana, and survives for seasons in the soil, in leftover infected debris and volunteers (self-sown plants left from a past crop), and in irrigation and drainage water — spreading on tools, boots and running water.
Scot Nelson · CC0 
Scot Nelson · CC0
Why it matters
Bacterial wilt can take your whole crop — up to 100% — and it does it fast: a healthy-looking plant can wilt and die within a day or two. Once the bacteria are inside a plant there is no spray or medicine that cures it, and they live on for seasons in the soil, in leftover plants and in drainage water, ready to strike your next crop. That is why everything rests on keeping it out — clean planting material, dry well-drained soil, and pulling up the very first sick plant before it seeds the whole field.
When to act
Act on the first wilting plants that do not recover overnight; rogue them immediately, as there is no chemical cure once plants are infected.
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 bacterial wilt field guide
- Identify it
- Scout for it
- Control it
15 field-guide sections in the app
The full guide to bacterial wilt — 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 bacterial wilt?
The first sign — sudden wilting while still green: in the heat of the day one plant flops over as if it is thirsty — but its leaves are still green, not yellow. Early on it may perk up a little at night, then within a day or two it wilts for good and does not stand back up in the morning, even after rain or watering.
When should I take action against bacterial wilt?
Act on the first wilting plants that do not recover overnight; rogue them immediately, as there is no chemical cure once plants are infected.
How do I control bacterial wilt?
Prevent it — start with resistant seed: where you can get them, plant resistant varieties (seed bred to shrug off the disease) or seedlings grafted onto resistant roots (a top plant joined onto tough, disease-fighting roots). This is your single strongest defence against a disease that has no cure.
Which crops does bacterial wilt affect?
Among the crops covered here: Eggplant, Groundnut, Tomato.
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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