Low adoption of productive agricultural technologies is a puzzle. Agricultural extension services rely on external agents to communicate with farmers, although social networks are known to be the most credible source of information about new technologies. We conduct a large-scale field experiment on communication strategies in which extension workers are partnered with different members of social networks. We show that communicator actions and effort are susceptible to small performance incentives, and adoption rates vary by communicator type. Communicators who face conditions most comparable to target farmers are the most persuasive. Incorporating communication dynamics can enrich the literature on social learning.