Innovation models such as the National Innovation System, open innovation, and the diffusion of innovation theory were built mainly from the experience of manufacturing and technology firms. Agro-based startups are increasingly asked to fit their growth into these same models, even though agriculture works under different conditions: biological time, fragmented landholding, weak rural infrastructure, and low-margin, trust-based markets. This paper reviews existing literature on innovation systems, agricultural innovation, and agro-startup practice to argue that generic innovation models do not capture the realities agro-startups face, and that sector-specific models are needed instead. The paper draws on recent empirical work on agro-based startup drivers and innovation capability to outline the building blocks of such a model and discusses what this means for founders, investors, and policymakers. The paper closes with the limits of this conceptual approach and directions for future research.