Postharvest application of prohexadione-Ca and calcium chloride improves fruit quality and reduces mould development in strawberries

ABSTRACT Strawberries are very sensitive fruits prone to mechanical damage, water loss, and fungal attacks, especially grey mould ( Botrytis cinerea ), which is one of the main causes of postharvest diseases. Traditional methods of postharvest preservation, including applying preharvest fungicides and cold storage, have their own limitations, and therefore, effective alternative methods are needed. Prohexadione-Ca (Pro-Ca) and calcium chloride (CaCl 2 ) are environmentally friendly postharvest treatments that increase the shelf life of strawberries. These compounds reduce excessive growth, strengthen the cell wall, and deter enzymatic breakdowns, thus slowing down the ripening process. The current study determined the effects of different levels of Pro-Ca (10, 15, and 20 ppm) and CaCl 2 (1%, 2%, and 3%) on postharvest characteristics of strawberries kept at 4°C for 20 days. The retention of total soluble solids (TSS), titratable acidity(TA), vitamin C, phenolic compounds, and flavonoid contents showed significant improvements, accompanied by decreases in weight loss, severity of the disease, and microbial growth, with optimal doses depending on the specific parameter evaluated. The study highlights Pro-Ca and CaCl 2 as promising and sustainable postharvest treatments of strawberries as a safer substitute to the traditional chemical fungicides, which also fits the current consumer demands of natural products. Additionally, the use of these treatments not only improves the quality of fruits but also leads to economic sustainability through alleviating postharvest losses.