Winter oilseed rape survey

Brown rust risk map
Monitoring Regional Disease Risk
Winter Oilseed Rape Survey

Data from the Defra Winter Oilseed Rape Survey of England and Wales for the years 1990 to 1999 have been used to generate maps illustrating overall risk of individual diseases over this period. Data for light leaf spot, phoma canker, alternaria pod spot and sclerotinia stem rot are presented.

The survey data have been interpolated by kriging to produce a continuous surface of disease incidence. In order to restrict the maps to only those locations where winter oilseed rape is grown, the data have been plotted onto a grid mask of the winter oilseed rape cropping area.

Light leaf spot
Light leaf spot

Mapping of incidence of light leaf spot in spring shows that the risk of infection is highest in the north and west of England.
Alternaria pod spot risk map
Alternaria pod spot

Incidence of alternaria pod spot has been very variable over the last ten years, depending on weather conditions. Risks are highest in the south.
Phoma canker risk map
Phoma cankerw

Phoma canker is now the most common disease of winter oilseed rape with highest risks of disease occuring in the eastern and central counties of England.
Sclerotinia stem rot risk map
Sclerotinia stem rot

Risks of Sclerotinia are generally low and localised. When conditions are conductive for disease development, risks have been highest in the Herefordshire area.