Clubroot disease is a serious threat to OSR production in Sweden and genetic resistance is the most important factor in a cropping strategy. The aim is to develop a concept for integrated production of winter OSR supported by DNA technology. Infestation levels and yield of resistant and susceptible varieties grown in fields with different infection levels of Plasmodiophora brassicae are investigated. Three resistant varieties of winter OSR are selected together with a mixture of susceptible varieties in six field experiments in fields of low, moderate, high and very high infection levels. Plot-wise DNA analysis of soil are correlated with disease severity and yield. Bioassays are carried out for optimal infection. The presence of virulent isolates breaking reistance of Mendel are identified and determined by classical methods. The potential risk of oil radish as a catch crop is investigated.The goal is to provide an improved support and guidelines for sustainable winter OSR production.