We run a randomized controlled experiment in which farmers trained on a new rice cultivation method (SRI) teach two other farmers selected by us. We find that farmers invited to teach others are much more likely to adopt new practices than farmers who only receive the BRAC training. Teacher farmers are effective at spreading knowledge and inducing adoption. Incentivizing teachers improves knowledge transmission but not adoption. Matching teachers with farmers who list them as role models does not improve knowledge transmission and may hurt adoption. Using mediation analysis, we find that the knowledge of the teacher is correlated with that of their student, consistent with knowledge transmission. We also find that SRI knowledge predicts adoption of some SRI practices, and that adoption by teachers predicts adoption by their students, suggesting that students follow the example of their teacher. Explicitly mobilizing peer-to-peer (P2P) transmission of knowledge thus seems a cost-effective way of inducing the adoption of new agricultural practices.