In 1998, a survey of the incidence and severity of diseases was carried out on 30 crops of winter linseed at early flowering and again at crop maturity.The overall objevtives were to determine the occurrence of diseases on winter linseed crops in the UK (ADAS); to quantify effects of diseases on growth and yield of linseed crops, using fungicides; to evaluate the importance of diseases in winter linseed crops in the UK.