Evaluation des risques liés à l’utilisation de semences non traitées sur le rendement et la qualité grainière du blé tendre d'hiver

Planting seeds treated with conventional fungicides is a common practice in conventional agriculture since several decades. This practice is especially aimed at controlling seed- and soil-borne pathogens that may affect crop yield and quality. More specifically to winter wheat, two key diseases, namely common bunt, caused by Tilletia spp., and Fusarium head blight, caused by Fusarium spp may severely affect yield and quality in the absence of seed treatments with conventional fungicides. However, there is little knowledge about the economic risks of planting wheat seeds without chemical seed treatments. To fill this knowledge gap, a large-scale on-farm trial was conducted over 6 years (2019-2024) to assess the risks of planting wheat seeds without chemical seed treatments in the Grand Est region, North-East France. Overall, our results show that, except for a few exceptions, planting wheat seeds treated with conventional fungicides does not increase grain yield and quality. These results are encouraging for French farmers who are willing to give up planting seeds treated with conventional fungicides due to increasing concerns about human health and the environment.