Control Undertake crop rotation and good hygiene as for blackleg control. In some countries sclerotinia stem rot is the most important disease of canola. It is widespread in Western Australia, but generally not severe. Symptoms Usually the stalk rots just above soil level , causing the plant to wilt and ripen prematurely. Severely attacked plants can lodge.
Affected tissues are usually a leached greyish white or brownish white.
The stem can also be infected 30 to 45 centimetres or more above the soil surface. Cause Sclerotinia stem rot is caused by the fungus Sclerotinia sclerotiorum . Sclerotinia can survive as sclerotia in the soil for many years. The fungus probably also survives in the soil by colonising the roots of other plant species. During cool moist weather sclerotia near the surface germinate and produce small, cream, mushroom-like bodies called apothecia, containing many ascospores.