Club root is a fungal disease of the roots of brassicas, including cabbage, Brussels sprouts, cauliflower and swede.
Above ground affected plant will have stunted growth, purplish foliage and wilting in hot weather, which may recover in wet conditions. Underground the root system becomes swollen and distorted, with a loss of fine roots. Growth and yield are greatly reduced and badly affected plants may die.
There are no chemical controls for club root disease.
Prevention is better than cure: