ABSTRACT This research was conducted in Tigapanah District, Karo District, North Sumatra from November 2021 to September 2022. The aims of this study were to: (1) identify the agricultural extension system in Tigapanah District, (2) identify the role of agricultural extension workers in Tigapanah District, (3) identify dynamics of horticultural farmer groups in Tigapanah District, and (4) …