Pesticide use and climate-driven pest pressure in smallholder agriculture in equatorial Africa

Despite extensive research on agriculture and climate in equatorial Africa, few studies integrate hydroclimate change with land use, crop vulnerability, pest and pathogen pressures, and the increasing dependence on pesticides in smallholder systems. Therefore, this study evaluated how changing hydroclimate conditions may influence pesticide use in smallholder landscapes surrounding a forested national park in western Uganda. Recent and projected trends in temperature, precipitation, and soil-water availability were used to assess future crop suitability and pest and pathogen impacts on major crops, while interviews with local stakeholders provided insight into the extent and risks of current pesticide use. Results showed that warming and wetting trends over the past several decades are expected to continue until at least mid-century. The current warming and wetting trends may strengthen and weaken, respectively, in the future. Despite the changing climate, temperatures and soil-water availability of the region as a whole should remain suitable for the current suite of crops grown there. Unfortunately, the combined effects of changing hydroclimate variables are likely to increase pest and pathogen pressure on crops. Interviews indicated that pesticide use is widespread and increasing, driven by pest outbreaks, labor constraints, and market pressures, with misuse, low adoption of protective equipment, limited extension support, and health and environmental impacts. Therefore, pesticide use is expected to increase further in upcoming decades, posing growing risks to farmer health, wetlands, and wildlife. Sustainable pest-management strategies, exemplified by integrated pest management, together with improved extension services, will be essential to reduce chemical exposure while maintaining yields.