In France, as in many other countries, sellers of phytosanitary products occupy a strategic place in the agrifood sector since they often play an advisory role to their buyers, in addition to their activity of selling inputs. For several years, the public authorities have put in place a system of points (so-called certificates) offered to retailers who make the effort to reorient their activity towards the sale of more environmentally friendly products and the promotion of actions in favor of the environment, such as putting farmers in contact with providers of alternatives to pesticides. Unfortunately, retailers are struggling to collect a sufficient number of certificates to bring about a significant change in farmers' practices. Certain green actions are very rarely carried out, although they yield a lot of certificates, are inexpensive to implement and have a proven positive effect on the environment. This study aims to change retailers' aversion for a key action of the scheme, namely collecting a new minor crop from farmers. In a randomized controlled trial (RCT), we nudge retailers, with the aim to improve their understanding of the certificates system and to remind them of the environmental gains associated with the introduction of a new minor crop into the landscape. Half of the resellers who volunteer to participate receive the nudge, while the other half do not. Next, both groups participate in a discrete choice experiment (DCE) to provide estimates of their preferences for a number of green actions (including collecting a minor new crop). The experiment aims to evaluate the impact of the nudge on responses to the DCE, that is to say, the impact on the retailer's willingness to collect a new minor crop of great importance for the environment.