Temporal and spatial dynamics of improved rice variety diffusion across Senegal’s production systems

Rice self-sufficiency is a strategic priority in Sub-Saharan Africa (SSA), where the diffusion of improved rice varieties (IRVs) remains constrained by institutional and agro-ecological heterogeneity. In Senegal, the National Rice Self-Sufficiency Programme has strongly promoted IRV adoption, yet evidence remains limited on how adoption unfolds over time and how it varies spatially across contrasting production systems. Using primary survey data collected in 2026 from 474 rice producers in irrigated and rainfed systems, this study provides a descriptive assessment of IRV diffusion dynamics of Improved Rice Variety Diffusion Across Senegal’s Production Systems. We combined bivariate comparisons (t-tests and c²) with a logistic growth model to trace the temporal adoption trajectory and identify tipping points. Spatial analysis documents adoption rates and intensity across seven regions. Results showed an overall adoption rate of 57.69%, with pronounced spatial heterogeneity: irrigated areas reach near-universal adoption (Saint-Louis 96%, Matam 95%); while rainfed regions lag significantly (Tambacounda 18.18%, Sédhiou 22.67%). Adoption dynamics followed a logistic diffusion pattern, with a tipping point around 2010-2011, coinciding with PNAR operationalisation. However, certified seed use remained low (35.83% overall), revealing a gap between varietal adoption and qualitative seed access, particularly in rainfed systems. The probit model confirmed that literacy, rice-growing area, fertiliser use, technical supervision and banking access were positively associated with adoption; while experience and total household area showed negative associations. These findings suggest that a national rice policy must shift from uniform input distribution toward geographically targeted support and seed system strengthening in lagging rainfed areas. Thus input subsidies alone are insufficient to sustain equitable diffusion without strengthening institutional support and seed systems in lagging regions.