10th U6+ Consortium of African Universities International Conference

Agriculture remains a cornerstone of Nigeria's economy. However, post-harvest losses of perishable farm produce continue to undermine food security, reduce smallholder farmers' incomes, and impede sustainable agricultural development. These losses are largely attributed to inadequate market access, fragmented distribution systems, and limited digital integration across agricultural value chains. This study presents the design, development, and usability evaluation of Agro9ja, a web-based marketplace that connects farmers directly with buyers through a secure, user-friendly digital platform. The system was developed using an Agile prototyping approach and implemented with WordPress, using web programming languages such as PHP, MySQL, HTML5, CSS3, JavaScript, and Bootstrap. Its core functionalities include farmer registration, produce listing, location and category-based search, administrative moderation, and direct buyer–farmer communication. Usability was evaluated through a pilot study involving 30 participants, including farmers, produce buyers, and information technology professionals, using the System Usability Scale (SUS) and Nielsen's usability heuristics. The evaluation recorded a 99.1% task completion rate, a mean user satisfaction score of 4.61/5.00, and a SUS score of 87.3/100, indicating excellent usability and a highly intuitive user experience. The findings demonstrate that Agro9ja effectively enhances farmer visibility, improves buyer access to fresh produce, and strengthens market connectivity. The study highlights the potential of localized digital agricultural marketplaces to support Nigeria's agricultural transformation agenda by reducing post-harvest losses, improving rural livelihoods, fostering inclusive economic growth, and advancing the achievement of Sustainable Development Goals