Quantification of the losses and characterization of fruit of six peach cultivars during thinning

Abstract

Accurate estimation of agricultural food loss and waste is key for its management. This study estimated and characterized thinned peaches from six cultivars over five years in a commercial orchard. Fruit weight, size, and color were analyzed, and relationships with agro-meteorological variables were established through multivariate analysis. The quantification of thinned unripe peaches revealed substantial waste (between 250 and 7000 kg/ha). Particularly, seasonal and late-season cultivars thinned much more fruit (>92 %) compared to early cultivars. Our results exceeded between 4 and 10x those previously reported. Significant yearly fluctuations were observed: 2021 (3761 kg/ha) and 2023 (3150 kg/ha) had 4–5× more waste than the others, suggesting that climate—especially frost and mid-season precipitation—is the main driver, even outweighing cultivar differences. It was determined that the ratio of fruit kilograms per trunk cross-sectional area (kg fruit/cm2TCSA) is a reliable indicator for quantifying discarded fruit and is easier to measure than kg fruit/m3 of canopy. Color attributes showed yearly and seasonal variations, indicating that climate affects pigment development. The results suggest that selecting suitable cultivars and monitoring weather patterns can improve thinning predictions. Given the large amount of discarded fruit, there is an urgent need to find ways for its agro-industrial reuse.