Drawing on a socio-technical systems perspective we compare the ways in which novel genetically modified (GM) crop artefacts, related devices and techniques, actors, practices, and institutions have been linked together, or configured, across two distinctive cotton production systems in north east Argentina, one based around large-scale farming and the other based around small-scale family farming. In the former system, new GM seeds, actors, complementary artefacts, agricultural techniques, and technical support, and modified supply markets and regulatory rules have been linked together in ways that mean agricultural biotechnologies perform well. In the latter system, the new GM artefacts were unavailable, whilst conventional seeds disappeared from input markets. Instead, linkages were formed between informal seed multipliers and dealers, copied GM seeds, of unreliable identify and poor quality, unmodified production practices, declining technical support, uncontrolled pest problems, and an absence of regulatory oversight, resulting in a poorly performing technology. In effect, working agricultural biotechnologies are different in the two farming systems; they have different characteristics and capabilities and perform in different ways.