This paper identifies market failures that limit agricultural R&D for Africa and other resource-poor environments, and proposes a mechanism to help circumvent them with cash prizes for the dissemination of successful innovations. The proposed prize institution would use ex-post experiments and farm surveys to document the value of innovations after their initial diffusion, to avoid pre-specification of technologies. Prizes would be offered in proportion to estimated social benefits, and would buy innovations into the public domain so that innovators with marketable technologies would choose not to apply for prizes. A governance structure to ensure credibility and financial sustainability is proposed.