© 2014 John Wiley & Sons, Ltd. Successful uptake of modern irrigation techniques and farmer decision support tools are necessary to promote the sustainable use of water resources. However, many of these tools fail to receive sufficient uptake from farmers to have a significant impact on water saving. End-user participation during tool development can increase the adoption rate as the tool becomes more usable. In the Segura River Basin of Spain, an irrigation advisory bulletin was designed to support farmers in their irrigation planning and scheduling. The bulletin was distributed to innovative farmers who are early adopters of modern irrigation technology. A formative evaluation procedure was applied to assess the acceptability of the bulletin against a number of non-adoption criteria, including irrelevance, inflexibility, inaccessibility, lack of confidence and institutional and political barriers. Feedback from the pre- and post-trial run surveys revealed that there were discrepancies between perceived and actual information needs by farmers, which include seasonal influences, water quality, salinity levels and crop life cycle. We demonstrate and argue the importance of assessing end-user needs again after the implementation of the decision support system in order to limit the risk of non-adoption.