Bacterial Canker
Risk near you, next 48h
See whether your local forecast favours this disease right now.
When it strikes
Remove affected material now
Take out the affected leaves, shoots or whole plants before the next wet spell, bag them as you cut, and wash your hands and tools before touching healthy plants.
Rain and irrigation splash
Water splashing off soil and infected leaves carries it upward and along the row. Watering at the base and mulching the soil surface break the route.
It carries over to next season in soil, debris or seed — which is why rotation matters here, not just treatment.
Keep out of the compost
This survives a garden heap. Bag it for municipal green waste, which is composted industrially at temperatures a garden heap cannot reach, or burn it where that is permitted.
When and where to look
Scout the planting while temperatures hold between 16°C and 28°C, with humidity above 80%, after rain or heavy dew, while the leaves are still wet. Risk builds after roughly 6 unbroken hours of those conditions, so the morning after such a night is the moment to look.
The signs that lead here
Full problem lists for these crops
About
Bacterial canker (Clavibacter michiganensis in tomato; Pseudomonas in stone fruit) is a serious seed- and water-borne disease that causes wilting, cankers and fruit spotting in cool, wet conditions.
Symptoms
On tomato, one-sided leaf wilting and scorching, light streaks on stems, and 'bird's-eye' spots with white halos on fruit; on trees, sunken oozing cankers and dieback.
Organic Treatment
Remove and destroy infected plants, sanitise tools and stakes, and use hot-water-treated seed. Prune trees in dry weather and apply copper.
Chemical Treatment
Copper sprays slow spread but do not cure; no effective curative bactericide.
Prevention
Use certified clean seed and transplants, rotate for 2–3 years, disinfect stakes and tools, and avoid overhead watering.
Crops at risk
Related problems
Bacterial Canker risk by location
Each location has a month-by-month profile computed from the weather archive: how many hours a year actually meet this disease’s thresholds.