Scaling Last‐Mile Seed Access Through Quality Declared Seed: Impacts on Improved Sorghum Uptake and Yields in Tanzania

ABSTRACT

Although sorghum plays a vital role in income generation, food, and nutritional security in Tanzania, access to quality seed and adoption of improved varieties remain low. Community‐based seed producers can enhance farmers' access to quality seed, yet their impact on the adoption of improved varieties and, subsequently, improving productivity has not been studied. Our empirical strategy relies on treatment effects matching, propensity score matching, inverse probability weighting, and regression adjustment. Data from 1492 farming households across the major sorghum‐producing regions of Tanzania showed that farmers were, on average, 35 km away from the main markets, relied on farm‐saved seeds and on their peers for information regarding production, seed knowledge, and markets. Adoption of improved sorghum varieties was at least 10% higher in treated than in control wards. The results suggest that if each ward had a QDS producer, adoption would increase by at least 14%. Farmers in treated wards allocated a minimum of 9% more of cultivated area to improved varieties compared to those in control wards. Productivity was higher among households using improved varieties, with gains of at least 55 kg/ha relative to non‐adopters. The average treatment effect ranged between 55 kg and 77 kg/ha. This estimate is a model‐based scaling scenario for the surveyed sorghum‐producing wards and should be interpreted as the expected gain from scaling out QDS producers' presence to comparable contexts. If the estimated area of 0.9 million ha of land under sorghum in Tanzania was grown to improved varieties, national production would increase by between 49,500 and 69,300 metric tons per season, translating to an estimated value of between USD 28.4 million and USD 39.8 million in additional revenue. These results underscore the importance of promoting decentralized seed production and distribution to broaden access to quality seed and increase the adoption of improved varieties and productivity in underserved communities. We propose evolving QDS production into an “in situ agrodealership” model that bundles quality‐declared seed with embedded advisory services and access to complementary inputs. This model complements (rather than replaces) private agrodealers by reaching last‐mile farmers through replicated producer networks across districts within existing QDS marketing rules, thereby increasing adoption and productivity at scale.