Post-harvest handling practices and effect on market performance: A case of onion traders in Kampala.

Abstract

This study investigated post-harvest handling practices and their effect on market performance among onion traders operating in Kalerwe and Kasubi markets of Kampala, Uganda. The study addresses a critical gap in understanding how these selected practices influence market performance outcomes in the onion subsector. A cross-sectional survey was conducted from June to August 2025, involving 102 onion traders comprising 72 retailers and 30 wholesalers. Data were collected using structured questionnaire capturing demographic variables, adoption of recommended post-harvest practices (and market performance metrics in form of sales volume, value addition, and profit margins. The recommended post-harvest practices included: sorting and grading, packaging, transporting, and storage. Descriptive statistics and Ordinary Least Squares (OLS) regression were employed to analyse the data. The study findings show that storage practices among retailers were universally adopted at almost 100%. The sorting and grading are most prevalent among divorced retail traders at 87.5% and those traders aged 31–35 years at 75.9%. Packaging and transporting showed lower adoption, particularly among retailers identified as single at 44.4% and those with primary education at 40.0%. Wholesalers demonstrated near-universal adoption of packaging, transporting, and storage at 100%, while the adoption of sorting and grading is highest (100%) among younger traders aged 20–25 years. Retailers recorded an average annual sales volume of 8,342 kg and an annual profit margin of Ugx. 4.9 million, with packaging linked to the highest annual sales (8,591.9 kg). Wholesalers achieved significantly higher quantity of sales of 41,901.3 kg and corresponding gross profits of 22.5 million UGX with consistent performance across practices. Findings from Ordinary Least Square (OLS) regression indicated non-significant effects of post-harvest practices on sales and profits for both groups, with sorting showing a slight positive effect (r = 0.2 for wholesalers, P = 0.317). These findings suggest that post-harvest practices are widely adopted, their impact on market performance of onion is positive but insignificant limited, a phenomenon that can be attributed to Market conduct of traders, who prefer dealing small quantities that can sell in a short period, and therefore necessitating a limited need to store. The lack of appropriate infrastructure could also be limiting quantities that wholesalers can procure and distribute in the markets. Targeted capacity building interventions are needed to enhance the adoption of these selected practices in the short run, and also to evaluate the kind of storage infrastructure that traders find appropriate for them to increase the amount of onions stored and therefore enhance market performance in the long run.