Mainstream agricultural research has focused primarily on technical and biological aspects and is aimed at controlling or manipulating nature through the use of external inputs, such as
agricultural chemicals or super seed. In developing countries, the results of this research have benefited some resource-rich farmers in well-endowed areas, were suitable to only a limited
extent for poorer farmers in the more favourable areas, and were - in most cases - completely inappropriate for small-scale farmers in marginal areas, e.g. in the mountains or the drylands.

This paper investigates Innovation Systems Concepts and Principles starting with an historical perspective. Then it analyzes their application to Integrated Agricultural Research for Development (IAR4D) and makes a comparison between the traditional Research and Development Systems Approaches and the Innovation Systems Approach. 

This study introduces a framework for managing information flow in innovation systems. An organisation's capacity to receive information, to share it with others and to learn from it is assumed to be the key factor that shapes the flow patterns and, hence, the performance of the innovation system concerned. The framework is applied to characterise the information structure underlying the agricultural innovation system of Azerbaijan and to develop an information strategy for the system to accelerate the information flow.

Innovation system approach offers an holistic, multidisciplinary and comprehensive framework for analyzing innovation process, the roles of science and technology actors and their interactions, emphazing on wider stakeholder participation, linkages and institutional context of innovation and processes. This paper was aimed to: 1. review the concept of innovation system; 2. appraise the application to agriculture and its relevance and 3. analyze the policy implications for agricultural extension delivery in Nigeria.