Clubroot of Brassicas

Plasmodiophora brassicae


Thickened taproot and laterals with eventual decay of roots. Weak and stunted plants. Premature wilting of plants, especially on hot days.

Species Affected:

Brassica crops and weeds.


Favoured by warm wet weather and poorly drained acidic soils.
Often carried by Brassica weeds.
Spread by movement of infected soil, water flows or seedlings.

Life Cycle:

Spores may remain in the soil for more than 20 years.

Origin and History:



Management and Control:

Use a 3-year rotation to non-Brassica crops.
Use healthy seedlings. Destroy any with enlarged or distorted roots.
Fumigate infested seedbeds.
Apply lime to acidic soils to bring pH to more than 7.
Apply Calcium or Boron if necessary.
Apply fungicides.

Related and Similar Species:


(Donald et al., 2002)


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