Species have requirements for particular physical conditions; for example, S. officinarum needs higher precipitation and maximum temperature than Hylocereus polyrhizus (F.A.C. Weber) Britton & Rose. Despite these opposite requirements, Sangay gardeners are exchanging S. officinarum for H. polyrhizus, supporting our idea that crop selection can be associated more with socioeconomic than environmental factors, as concluded elsewhere (Pulido et al., 2008)