PR - Sustainable Management Of Varietal Resistance To Blackleg In Rapeseed

Blackleg, a major disease in rapeseed, can be managed using varietal resistance. However, to minimize resistance breakdown, other management techniques must also be used. We studied current agricultural systems used to manage rapeseed and blackleg on farms by means of a survey in two French regions. The data obtained were summarized and eight main systems were identified with an associated risk level of resistance breakdown. Rapeseed return time and varietal diversity were not the only techniques used by farmers to manage blackleg. Each system was also characterised for its capability of integrating current agronomic advice. Risky types were not always found in areas where blackleg was relatively rare. Less risky types would be able to improve their management whereas risky types may not have any leeway to include agronomic advice in their system. These data are now used to develop farming systems integrating agronomic advice and farmer’s objectives and resources.