Sanitary requirements are strengthening in response to consumers' expectations, European regulations and private actor's requirements, through retailers, in particular. Farmers are directly concerned by the dynamic, which has emerged for the last twenty years, since specifically the “mad cow” crisis. Mayotte is a French overseas department since 2011 and an ultraperipherial region of Europe since 2014. It is supposed to comply to European requirements. However, numerous studies highlight that the retrofit between practices and sanitary expectations is not already achieved. In order to answer this inadequacy in a context where almost 80% of the total production is informal, we have surveyed 47 tomatoes producers. This production is very sensitive to pests and particularly to tomatoes fly during the dry season, which can destroy all or some parts of the harvest. We demonstrate that more than producers' individual characteristics, numerous exogenous factor could help understand the inadequacy observed. Institutional environment could be a brake as well as a leverage to setting up more environmental friendly practices.