E. Alimirzaei - Department of Agricultural Extension and Education, College of Agriculture and Natural Resources, University of Tehran, Islamic Republic of Iran.
S. M. Hosseini - Department of Agricultural Extension and Education, College of Agriculture and Natural Resources, University of Tehran, Islamic Republic of Iran.
S. Y. Hejazi - Department of Agricultural Extension and Education, College of Agriculture and Natural Resources, University of Tehran, Islamic Republic of Iran.
H. Movahed Mohammadi - Department of Agricultural Extension and Education, College of Agriculture and Natural Resources, University of Tehran, Islamic Republic of Iran.

The performance of a pluralistic extension and advisory system is strongly influenced by the presence of multidisciplinary professional actors and their executive interactions for synergistic achievements in a balanced institutional framework. The specific purpose of this study was to explore the institutional boundary of Iranian pluralistic extension system and the extent to which the multiple providers interact with each other in implementation of related programs. A sequential mixed methods research was developed. Qualitative data were collected via semi-structured interviews, and were analyzed by theme analysis. Quantitative data were gathered using a researcher-made questionnaire and were analyzed by social network analysis. According to the qualitative findings, multiple service providers were classified into ۲۱ distinctive institutional categories. Also, findings showed that the current executive network was not satisfactory in terms of institutional coherence, such that a few dominant providers were very influential in the center, while most of the others had little linkages and thus power at the margin of the extension network. Such a highly centralized network is unsustainable and vulnerable from different viewpoints and cannot fulfill the tasks expected from extension system in Iranian heterogeneous agriculture sector. In this regard, establishing a multi-sectoral institutional platform to focus on enhancing mutual coordination and combining collective actions is recommended as an important structural adjustment in the current extension system. To this end, facilitating roles of the public extension agency as the most influential actor of the existing extension network will be extremely significant.

Agricultural innovation, Executive relationships, Professional relationships, Social networks., نوآوری کشاورزی, نظام ترویج کثرت گرا, ارتباطات اجرایی, شبکه های اجتماعی