Club Root
Club root is caused by the fungus Plasmodiophora brassicae, a slime mold fungus.This fungus enters the plant through fine hairs on the young roots or through wounds in secondary roots. As the "clubs" enlarge the fungus produces a mass of spores which are released as the root tissue decays.
These spores can be transferred from one area to another on shoes, on equipment or in soil water and can survive in the soil for a long period - at least 10 years and possibly 20.
Several different practices need to be used to control club root most of which are well known. These include:
- Practicing long rotations where possible.
- Choosing soils that are free draining.
- Eradicating crucifer weeds e.g.shepherds purse and fat hen which can harbor the fungus
- Raising the pH - but an already high pH is not necessarily enough - the lime must be applied in the year of growing the crop.
- Increasing the pH of the module compost.