Food loss and waste (FLW) reduction is recognised as one of the strategies to promote sustainable food systems and efficient resource use. Despite substantial global efforts to address FLW across supply chain stages, measuring and estimating FLW at the primary production stage remains a significant challenge. Pre-harvest losses of mature crops due to pests, diseases, and climate events, as well as unharvested mature crops for several reasons are invisible in global reporting and policy, despite their impact on farm-level efficiency, resource use and food availability. This review adopts a narrative synthesis approach to examine definitional ambiguities and boundary issues in timing-based loss categories, the various aspects of pre-harvest loss that are inconsistently interpreted within the FLW domain, and the broader challenges of assessing FLW at the farm level, particularly in perishable crops. By treating pre-harvest loss as a key analytical focus, this review shows that blurred boundaries are not simply definitional issues but a structural source of bias through which significant portions of farm-level loss are either hidden or indirectly absorbed into other stages of the FLW framework. Despite these structural challenges, several scholars and organisations acknowledge the need to integrate pre-harvest losses into FLW assessment to capture the actual environmental, social, and economic costs of inefficiencies in the food system. However, achieving this integration requires standardisation of terminology and clearer delineation of system boundaries. This includes greater clarity on what constitutes food loss and waste on farms and on the scope of pre-harvest, harvest and post-harvest losses, to ensure data consistency and comparability. • On-farm measurement challenges of perishable horticultural crops are reviewed. • Pre-harvest loss is inconsistently defined and represented across FLW literature • Definitional and boundary ambiguities between pre-harvest, harvest, and post-harvest stages have direct statistical and reporting consequences • Unharvested mature crops fall into an unresolved gap in FLW classification • Improvements in on-farm measurement approaches are proposed to better capture farm-level losses and support broader FLW reduction efforts
Pandey et al. (Sun,) studied this question.