Sclerotinia sclerotiorum

White mold, Sclerotinia cancer or even rape is a plant disease caused by the fungus Sclerotinia sclerotiorum. It can affect various cultivated and wild plant species, economically important damage it is addressed, however, only in rape fields.

The importance of white mold in rapeseed cultivation is greater than in southern Germany in northern Germany. Usually bleaches after flowering the stems of infected plants without sharp demarcation from the healthy tissue from. The infested zone, usually starting from a branch or petiole, is white, the bark dissolves bastartig from the stems and the plant parts above the infection site die. Often the stem bends in this white area. In stems Inside are initially white Mycelverdichtungen, skip the later black, irregularly shaped body length ( sclerotia ). When threshing they return to the ground, where they remain infectious for several years. The Sclerotinia infection is very dependent on the weather: warm moisture sections before flowering promote the formation of apothecia ( fruiting bodies ) of the sclerotia. The change of showers and sun during the flowering leaves the thrown from the apothecia spores in the leaf axils and Runner germinate when there adhere fallen petals as a nutrient source.

Combat

To combat Sclerotinia has a further distance in the crop rotation of rapeseed and the abandonment of the cultivation of other host plants (peas, sunflowers, potatoes). The fungus can also multiply on weeds, they are, therefore, to fight in the whole crop rotation. The specific control with fungicides against this disease officially recognized until now is based on the development stage full bloom. An appointment with infestation begins as cereal diseases is not possible in this disease.