History of chemical weeding from 1944 to 2011 in France: Changes and evolution of herbicide molecules

Abstract : Herbicide development in France has been analysed from a historical and agronomical perspective. A database was built up from data collected from the archives of the Ministry of Agriculture Food and Fisheries and from French phytosanitary compendia edited since 1961 by the Association de Coordination Technique Agricole. Only herbicides used in cultivated areas were retained. The first organic synthetic herbicides were registered on cereals after the Second World War. Since 1944, a total of 225 herbicidal active ingredients have been registered in France. The number of active ingredients regularly increased with a maximum of 138 in 2002; 104 were still authorized in 2011. Different combinations (maximum of 156 in 2002) were available that combined 2–5 active ingredients. On average, a given active ingredient has been used for more than twenty years. Nevertheless, some of them have been used for 67 years. A decrease in the number of active ingredients was observed after 2003 due to European and French strengthened regulations. The lack of tools to control some weed groups, the decrease in diversity of active ingredients in terms of HRAC groups and herbicide withdrawals in minor crops will inevitably lead to agronomical dead ends if no alternative solutions are proposed. This evolution induces a risk; the repeated use of fewer active ingredients belonging to a few HRAC (Herbicide Resistance Action Committee) groups may favour the selection of herbicide resistant weeds