Organic farming needs research on concepts and methods for selection and biodiversity conservation. This project aims to address these needs by developing new methods, knowledge and resources specific to organic farming. High diversity among organic systems requires more diversity among and within cultivars to enable them to cope with environmental variations. This strategy increases resilience and stability of cultivars in space and in time (Wolfe et al. 2008). In France, we have developed populations in a participatory plant breeding programme (PPB) in collaboration with Réseau Semences Paysannes (Farmer Seed Network, RSP) (Dawson et al. 2011). Our project started in 2005 with the creation of 90 populations by crosses from a broad genetic range. In 2012, there are 26 farms in France hosting those populations. The research team works in collaboration with the farmers in order to provide information for their selections. Researchers and farmers collectively conduct evaluations of the populations and make decisions about selections. In a mass-selection programme undertaken by the farmers on these populations, we analyzed the selection differential and response to selection and estimated realized heritability (h2r) for agronomical and morphological traits. Selection differential and response to selection were found positive for most of the traits of interest to the farmers. We also studied genotype-by-environment (GxE) interactions in the network of farms using two statistical approaches: the Finlay Wilkinson and AMMI models (Gauch et al. 2006, Nabugommu et al. 1999). Genotype by environment interactions were found highly significant for many traits. Using farmers’ practices and pedoclimatic data, we identified groups of farms that share similar profiles. These results will help us to understand the impact of the selection methods and organization on the evolution of the populations and the creation of new crops. Each year, these results are summarized in a report sent to the farmers in the programme prior to sowing, which helps to guide their selection process.