🦠Bacterial diseasesModerate

Crown Gall

Risk near you, next 48h

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When it strikes

Temperature
20–30°C
Humidity
≥60%
Leaf wetness
Not needed
Season
Spring, Summer

About

Crown gall (Agrobacterium tumefaciens) is a soil-borne bacterium that induces tumour-like galls on roots and stems of roses, fruit trees, grapes and many woody plants, entering through wounds.

Symptoms

Rounded, rough, woody galls at the soil line, on roots, or on stems, starting soft and cream-coloured then hardening and darkening; reduced vigour and stunting.

Organic Treatment

Remove and destroy severely affected plants; on minor galls, excise and treat wounds. Dip new roots in a Agrobacterium radiobacter K84 biocontrol before planting.

Chemical Treatment

No curative chemical; the K84 biological preventive is the standard protection for susceptible nursery stock.

Prevention

Buy clean nursery stock, avoid wounding roots and stems, treat susceptible plants with K84 at planting, and don't replant galled sites.

Related problems

Crown Gall risk by location