This paper develops a sequential game theoretic model of heterogeneous producers to examine the effect of co-operative involvement on innovation activity in the agricultural input-supplying sector. Analytical results show that the co-operative involvement in R&D can be welfare enhancing and, thus, socially desirable. The presence of the co-op can increase the arrival rate of innovations and productivity growth while reducing the prices of agricultural inputs. The effectiveness of the co-op is determined by the size of R&D costs.