Clubroot

Clubroot is a common disease of cabbages, radishes, turnips, canola and other plants belonging to the family Cruciferae (mustard family). It is caused by Plasmodiophora brassicae, which was once considered a slime mold but is now put in the group Phytomyxea. It has as many as thirteen races. Gall formation or distortion takes place on latent roots and gives the shape of a club or spindle. In the cabbage such attacks on the roots cause undeveloped heads or a failure to head at all, followed often by decline in vigor or by death. It is an important disease, affecting an estimated 10% of the total cultured area worldwide.