Participation of farmers in the genetic improvement of staple crops in vulnerable environments is now widely accepted as a necessary approach for enhancing the acceptance of improved varieties. Our study set out to assess the genetic gains achieved by collaborative decentralized participatory breeding programmes in comparison with those obtained by conventional breeding. The gains were estimated on farmer acceptance and combination of agronomic and quality-related traits, from three breeding programmes on tortillero sorghum for low-input cropping systems in northern Nicaragua. In each pro-gramme, three selection modes were compared: selection by the farmers on-farm (FoF), by the breeder on-station (BoS), and by the breeder on-farm (BoF). Our results showed that the lines produced by FoF selection were more praised by the farming community, compared to BoS and BoF selection. Comparative advantage of FoF selection was to develop higher proportion of lines with an adequate balance between agronomic traits, and with better quality traits related to grain appearance and plant type. A composite selection index, ISFA, was computed for each line as a combination of agronomic performance in the target environment, and ex post farmer appraisal. Based on this index, FoF selection proved again to be more efficient than BoS and BoF selection. We propose that such a selection index be used in participatory breeding programmes to improve their efficiency.