Combined effects of prohexadione‐calcium and growing environment on sweet cherry fruit quality and postharvest performance

BACKGROUND Sweet cherry (Prunus avium L.) is a high-value fruit crop, but its commercial success is often limited by poor pigmentation, reduced firmness, and short shelf life. This study evaluated the effects of preharvest applications of prohexadione-calcium (1.5 L ha-1) on fruit quality and storage performance in lowland and hilly orchards in northern Italy.RESULTS Fruit size, weight, firmness, soluble sugars, organic acids, and nutraceutical compounds were measured at harvest and after 14 days of cold storage (2 degrees C, 75% RH). The firmness of the treated fruits from the hilly orchards was consistently higher and remained stable during storage, while the control fruits experienced an increase in firmness due to dehydration. Prohexadione-calcium also had an impact on the metabolic composition: in the lowland orchards, the sugars in treated fruits increased, whereas they decreased in the controls, and the opposite trend was observed in the hilly site. The organic acids showed varying responses depending on the site, but generally, the treated fruits retained more tartaric acid and maintained more stable sugar-acid ratios during storage. The nutraceutical qualities were better preserved in the treated fruits, especially at harvest in the hilly site and after 7 days in the lowland site.CONCLUSION Prohexadione-calcium enhanced firmness and nutraceutical stability, improving the postharvest quality of sweet cherries across different growing conditions.