As swedes belong to the brassica family they can be prone to Clubroot disease. The foliage of swede becomes yellow, pale pinkish in colour and wilts in sunny weather. Roots are swollen and distorted and plants grow slowly or die. Affected roots have an unpleasant smell. Affected plants can fail completely or produce a poor crop.
Cultural measures: Ensure land is adequately drained add lime to make soil more alkaline. Remove and burn all infected plants and avoid moving soil around the plot ie on boots and gardening tools. Plant resistant varieties. Practice crop rotation if applicable. Clubroot can remain viable in the soil for up to 20 yrs.
Raise plants in clean compost in individual pots of at least 5cm diameter. Plant out when plent of roots have formed. Consider growing club root reistant swede cultivars.
There are currently no chemical registered for the control of club root disease.