Regional study of herbicide resistance of Alopecurus myosuroides Huds. in France

International audience; Since the 1990s in the north-west of Europe, the spread of herbicide resistance in wheat weeds such as Alopecurus myosuroides Huds. (blackgrass) is becoming more and more important. In the French administrative district Côte d’Or resistance to fenoxaprop within A. myosuroides populations was first detected in 1996. In 2003, 149 fields from this district were randomly sampled and about 125 A. myosuroides populations were tested for herbicide resistance. The agronomic history of all sites was investigated. Most the populations of A. myosuroides investigated contained at least 50 % of plants with resistance to fenoxaprop. In 53 and 9 % of these populations at least 50 %…