Club root produces distorted, swollen roots on plants in the brassica family including broccoli, cabbages, cauliflowers and also related plants such as radishes, swedes, turnips and mustard. The flowering plants candytuft, stocks and wallflowers can also be affected.
Swollen galls form on the roots either as a large single one or in a cluster. In severe attacks the plants may be stunted and develop red-purple tints to the foliage. Wet soils and periods of heavy rainfall encourage the spread of the disease. Plants may suffer more in dry season as they lack a healthy root system. Club root is more likely to be a problem on acid soil and in this case lime can be added to maintain a pH of 7. Attacks can occur on alkaline soils if brassicas are grown too frequently and if soil temperature and moisture are favourable for disease diease to spread.
The disease is most likely to appear when two or three brassica crop have been grown succession. Infected seedlings can transfer the disease into clean land as can infected soil on boots and tools. Plants raised in 10cm (4") pots can achieve a reasonable crop and earthing up around the base of the crop plant will help to encourage new root growth.
Club root resistant varieties are becoming available and we offer seed of brussels sprouts, cabbage, cauliflower, and swedes that show good resistance.
There are currently no chemicals available for the control of club root.