Abstract: A method for supervising the treatment of a crop combines a field record, models of plants, diseases or insects and active substances coupled together, and includes, at least once, the following steps: a step in which the risk of contracting diseases to which the crop is exposed is determined, according to the results of a disease or insect model coupled with the plant model, a step in which the level of protection of the crop is determined based on the last treatment applied, according to the results of a model of active substances coupled with the field record and the plant model, a step in which the next recommended treatment is determined, according to the modeled change in the crop and the disease and/or insect since the last treatment carried out and a step in which the next recommended treatment is displayed.