The South African citrus industry is facing more and more difficulties due to strict agricultural export laws and more impending, pest and disease outbreaks, and large-scale farmers’ market dominance that marginalizes small and medium-sized producers. In order to improve small citrus farmers’ competitiveness and streamline adherence to phytosanitary regulations, this study proposes the conceptual design, analysis, and evaluation of a low-cost Autonomous Mobile Robot (AMR). The AMR’s ability to autonomously traverse citrus fields, particularly underneath trees, is a crucial component that allows for the early detection of pests and diseases from unusual perspectives, and combined with human intervention for analysis reduces the design cost significantly making it potentially accessible to all farmers in South Africa. In order to develop an optimised and cost-effective AMR, the research conducted feasibility studies, iterative cost-effectiveness analyses, and a systematic identification of the needs of smallholder farmers using a holistic conceptual design methodology based on systems engineering principles utilizing GENESYS Software. By combining object avoidance, geotagging, and multi-angle imaging features, the finished design enables South African citrus farmers to effectively record and track tree health with precision agriculture. The AMR can greatly increase the sustainability and financial sustainability of small citrus farms by offering a scalable and affordable substitute for current expensive agricultural automation systems. The results show that putting this technology into practice could improve market access for local farmers, lower operating expenses, increase the citrus industry’s resilience in South Africa, restabilizing the market, and reducing poverty in South Africa.