The need for an information development system for farmers is discussed in this paper. Issues and alternatives are described in terms of the research-extension-teaching trinity, extension services, role combinations, specialist advisor issues, innovations, research orientation, reward structures, and information services. Information gathered in the United States is presented along with information from other areas in the world. The author suggests that modernizing agriculture requires a specialized system which must provide for development, dissemination, and integration of new knowledge into individual farming operations; that the degree of functional differentiation and organizational specialization is related to the current state of agricultural development; that the utility of organizational arrangements in the system can best be judged in terms of the functional requisites that must be met; and that information systems require integration into the adopting situation. (PS)