Validating Indigenous Methods for Assessing Chili Dryness Using the DryCard Decision Support Tool in Senegal

Chili pepper (Capsicum spp.) plays a crucial cultural, nutritional, and economic role in Senegal, supporting smallholder livelihoods, domestic food systems, and regional export markets. However, post-harvest losses associated with traditional open-air drying and storage remain high, particularly under coastal conditions characterized by high relative humidity and variable weather. Improving drying assessment and storage practices is therefore essential to enhance chili quality, safety, and marketability. This study evaluated smallholder chili drying and storage practices in Senegal, with a particular focus on processor dryness judgment, drying surfaces, and storage materials, and assessed the potential role of a simple equilibrium relative humidity (ERH)-based decision-support tool. A participatory, on-farm study was conducted with six chili processors in the Niayes agroecological zone of western Senegal. Freshly harvested chilies were dried concurrently using black plastic sheeting and processors’ customary drying materials under farmer-managed conditions. Processor assessments of storage readiness were compared with ERH-based classifications using the DryCard tool. Drying duration and dry matter content were recorded for each treatment. Dried chilies were subsequently stored in either airtight glass jars or traditional gunny bags, and weight changes were monitored at 25, 45, and 70 days after storage. Data were analysed descriptively using within-processor comparisons to identify consistent patterns across sites. After 15 days of drying, all chili samples were classified as not dried for storage, with DryCard readings of approximately 75% ERH across sites. Final processor-determined drying durations ranged from 29 to 42 days. DryCard ERH values at this stage ranged from 30% to 70%, with three instances where processor judgement indicated storage readiness despite ERH values exceeding the 65% threshold. Dry matter content varied widely across treatments and sites, ranging from 7.4% to 18.3%. Chilies dried on black plastic sheeting showed higher and more consistent dry matter content (median ≈ 11.5%) compared with chillies dried on processor-preferred materials (median ≈ 9.1%). During storage, chilies kept in airtight glass jars maintained stable weights close to the initial 200 g over 70 days (199–201 g). In contrast, those stored in gunny bags showed progressive weight increases, reaching median values of approximately 208.5 g after 70 days. The study demonstrates that while experiential knowledge remains central to smallholder chili processing, it can be strengthened with simple, objective tools that support more reliable drying and storage decisions. Incremental improvements in drying surface selection, combined with ERH-based assessment and moisture-limiting storage, offer practical pathways for reducing post-harvest losses and quality risks. These context-appropriate interventions can enhance the safety, stability, and economic value of dried chilies without requiring costly infrastructure, making them well-suited to smallholder systems in humid environments.