Impacts of climate change on vegetable crop production, quality, and safety in Sub-Saharan Africa: A systematic review of tomato, onion, and pepper

Climate change poses escalating threats to agricultural systems in Sub-Saharan Africa (SSA), with vegetable crops among the most vulnerable due to their sensitivity to biotic and abiotic stresses. Impacts of climate change on crop productivity have been widely documented, but its effects on vegetable quality and food safety remain less comprehensively synthesized. This systematic review analyzes evidence from 140 peer-reviewed studies published between 2014 and 2026 to evaluate how climate variability and change affect the production, quality, and safety of tomato ( Solanum lycopersicum L.), onion ( Allium cepa L.), and pepper ( Capsicum spp.) in SSA. Findings reveal that climate impacts on vegetable quality are complex and context-dependent. Elevated temperatures, drought, erratic rainfall, and increased atmospheric carbon dioxide (CO 2 ) alter physiological processes and nutrient composition, affecting concentrations of vitamin C, lycopene, capsaicin, quercetin, sulfur compounds, and essential minerals. These responses depend on crop species, cultivar, stress intensity, timing of exposure, and post-harvest handling practices. Climate change intensifies food safety risks by favoring the proliferation of fungal pathogens and mycotoxin-producing species, increasing the incidence of bacterial diseases, and facilitating the spread of invasive pests such as Tuta absoluta and onion thrips. These challenges are further compounded by inadequate storage and cold-chain infrastructure, contributing to post-harvest losses (PHL) that frequently exceed 40% across many SSA vegetable value chains. Findings indicate that effective adaptation requires integrated pre- and post-harvest interventions, including stress-tolerant cultivars, climate-smart irrigation, integrated pest management, biological control agents, improved curing and storage systems, modified-atmosphere packaging, and digital climate advisory services. Major knowledge gaps identified are (i) predominance of studies examining single climate stressors, despite the reality that vegetables are increasingly exposed to multiple interacting stresses; and (ii) post-harvest quality and food safety impacts remain under-researched relative to production outcomes. In conclusion, this review suggests that: (i) safeguarding vegetable production systems in SSA requires a shift from yield-centered adaptation approaches toward strategies that simultaneously protect productivity, nutritional quality, and food safety; (ii) strengthening breeding programs for nutritional resilience, expanding affordable cold-chain infrastructure, and promoting integrated climate-smart technologies for enhanced food security, public health, and smallholder livelihoods under future climate change scenarios.