Pre- and postharvest losses and their correlates in the Irish potato value chain in Kenya

Food losses are a major constraint to agricultural productivity, farm incomes, and agrifood system efficiency in sub-Saharan Africa, yet comprehensive micro-level evidence across value chains remains limited. This study provides a detailed assessment of pre- and postharvest losses in the Irish potato value chain in Kenya, drawing on purposefully collected data from producers, aggregators and processors. Using a consistent, multidimensional measurement framework, the study captures both quantitative (physical) and qualitative (degradation) losses across production and postharvest stages. The results indicate that potato losses are widespread and occur throughout the value chain, with the largest share concentrated at the producer level. Preharvest losses and on-farm postharvest losses account for a substantial proportion (23.5 percent) of total losses, reflecting the combined effects of pest and disease pressures, weather-related shocks, and suboptimal management practices. Nationally, producer-level potato losses could amount to KSh 14.5 billion annually, equivalent to the annual per capita income of about 50,000 Kenyans. While producer-level losses dominate, descriptive evidence shows that potato aggregators and processors also incur nonnegligible losses, particularly during storage, transportation, and handling. These losses are commonly associated with spillage, mechanical damage, inadequate storage conditions, and poor handling practices, highlighting inefficiencies beyond the farm gate. Econometric results reveal that loss patterns vary across producers and production environments. Differences in demographic characteristics, farm size, labor availability, and market orientation contribute to heterogeneity in both the likelihood and intensity of losses. These results further demonstrate that asset ownership, management practices, and exposure to production risks are key determinants of loss outcomes. Greater household assets and labor availability are associated with reduced loss incidence and intensity, while exposure to biotic and abiotic stressors – captured through a composite index – significantly increases both the probability and severity of preharvest losses. Input use and management practices also play an important role. The application of chemical fertilizers is associated with reduced loss intensity, consistent with improved crop vigor and resilience, while the use of pest control is positively correlated with loss occurrence, likely reflecting reactive application following infestation. The adoption of improved seed varieties increases the likelihood of losses but reduces the intensity of them, which is a nuanced finding that suggests both greater exposure and improved resilience conditional on damage. Access to training and third-party agricultural service is associated with lower losses, underscoring the importance of knowledge and advisory support. This area also presents opportunities for youth, particularly young women, to engage in agrifood-system service provision through activities such as advisory services, quality management, aggregation, and postharvest handling, which can simultaneously reduce losses and generate income. Importantly, the analysis reveals strong linkages between preharvest and postharvest losses. Higher preharvest losses are associated with both increased likelihood and greater severity of postharvest losses, indicating that damage incurred during production propagates along the value chain. Overall, potato losses in Kenya are systemic but largely preventable through improved handling, storage, market infrastructure, and farmer capacity. Although youth sample sizes in this study are too small to quantify specific effects, the data highlight clear entry points for engaging youth, particularly young women, in reducing post-harvest losses. For instance, there are opportunities for involving youths in services offered at the production stage, which include sorting, curing, and transportation.