This article looks at how the generation of a cultivar may have unintended results forged as a plant breeding project is conceived and organized. Specifically, we investigate how a social rationality immersed in the scientific programs of modern agriculture guided the design of a new cultivar of lupine (Lupinus mutabilis Sweet), wherein which other seeds, rationales, spaces and actors were excluded. To develop this argument, we employ two methodological premises: cultivars can be understood as technological objects, and artefacts cannot be understood individually, since they are part of an integrated system.