club root

(finger-and-toe disease) A disease of crucifers caused by the fungus Plasmodiophora brassicae in which the roots become swollen and malformed. Above ground the symptoms, which may not appear for a while, are wilting and later stunting and yellowing of infected plants. Infection occurs via the root hairs and once the cambium is infected club roots develop rapidly. Spores can remain viable in the soil for several years making control difficult. Liming of the soil is a traditional control method.