Enhancing Spices and Oilseed Productivity and Technology Diffusion in Rural Bangladesh through Institutional Integration and Field-level Extension Services

Abstract

Aims: To evaluate the productivity and yield gap dynamics of high-yielding varieties (HYVs) of spice and oilseed crops under three management regimes, assess drivers of technical knowledge gain, and analyse stakeholder network interactions to strengthen Research-Extension-Farmer (REF) linkages in Bangladesh. Study Design: Participatory action research integrating comparative field trial evaluations, baseline and post-intervention structured socio-economic surveys, joint field monitoring, and Social Network Analysis (SNA). Place and Duration of Study: The study was conducted in two upazilas of Tangail district, Central Bangladesh, during a single cropping season under the coordination of the Bangladesh Agricultural Research Council (BARC), Bangladesh Agricultural Research Institute (BARI), and Department of Agricultural Extension (DAE). Methodology: Seventy-five cooperator farmers (25 farmers per management system) evaluated five BARI-released HYVs: mustard (BARI Sarisha-18), onion (BARI Piaj-4), garlic (BARI Rashun-2), turmeric (BARI Hallud-4), and chilli (BARI Morich-2) across ~0.33-acre plots per farmer. Performance was compared across Research-Extension Managed Trials (REMT), Extension Managed Trials (EMT), and Farmers Managed Trials (FMT). Capacity building involved participatory audio-visual training, joint interdisciplinary inspections, and field days. Pre- and post-intervention surveys quantified socio-demographic parameters, knowledge gain, and input/marketing channels, while SNA mapped network node interactions using centrality metrics. Results: REMT achieved the highest yields across all crops—mustard (2.40 ), onion (14.79 ), turmeric (16.00 ), chilli (22.00 ), and garlic (8.40 )—whereas FMT yielded the lowest. Yield gaps between REMT and EMT (12.50% in mustard, 15.48% in onion) were narrower than those between EMT and FMT (16.67% in mustard, 35.04% in onion). Post-intervention knowledge acquisition reached 95.24% among participants, driven primarily by extension services (62%) and research units (19%). Horizontal farmer-to-farmer information sharing reached 95.24%. Extension services and research stations supplied 95% of certified seeds. Social network analysis identified Upazila Agriculture Officers (UAO), Sub-Assistant Agricultural Officers (SAAO), progressive farmers, and BARI-OFRD scientists as key central nodes driving information flow and input supply. Conclusion: Integrated collaborative management, joint monitoring, and participatory training significantly narrow field-level yield gaps and accelerate HYV adoption. Policy initiatives should institutionalise multi-actor REF network linkages, expand digital advisory services, and improve seed storage infrastructure to optimise agricultural productivity in Bangladesh.