Bacterial Soft Rot of Brassicas and Onions

Erwinia species and Pseudomonas species

Erwinia carotovora, Pseudomonas gladioli pv allicola, Pseudomonas capacia and Pseudomonas aeruginosa in Onions


Wet, slimy rot of leaves, stems and heads. No fungal hyphae mould. Sometimes it has an unpleasant odour.

Species Affected:

Alliums, Brassicas.
Broccoli, Cauliflower and Onions are very susceptible.


More common in warm and wet conditions.
Often occurs after tissue damage from frost, hail, insect damage or sunburn.
Survives on crop residues and in the soil.
Spread by rain splash, mechanical means and insects.

Life Cycle:

Origin and History:



Management and Control:

Burn or bury infected plants.
Avoid high nitrogen applications.
Avoid harvesting in wet conditions.
Don't grow susceptible crops on infected areas for at least 2 years.


Use more resistant varieties.


Allow crop to fully mature before harvesting. Harvest carefully to minimise damage. Ensure bulbs are fully cured before storing in well-ventilated conditions.

Related and Similar Species:


(Donald et al., 2002)


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