Preharvest application of abscisic acid promotes fruit ripening, colour development and modulates phenylpropanoid pathway in early maturing ‘Yoho’ persimmon

Persimmon is cultivated globally for its distinctive flavour profile and nutritional benefits. Skin colour is one of the important harvest maturity indicators of persimmon fruit, and inadequate colour development in early-maturing cultivars presents significant economic challenges for growers. This study investigated the efficacy of preharvest s-(+)-cis, trans-abscisic acid (S-ABA) spray application on accelerating colour development and improving fruit quality parameters in ‘Yoho’ persimmon. Trees were treated with foliar application of S-ABA at concentrations 0 (control), 25, 50, 75 mg L−1 two weeks before anticipated harvest. Quality attributes of persimmon fruit were subjected to evaluation at one and two weeks post-application. Results demonstrated that S-ABA treatment significantly enhanced colour indicators, including colour index, a*, b*, and chroma values at both harvest intervals. Harvested fruit treated with spray application of S-ABA (25 and 50 mg L−1) showed higher soluble solids content (SSC), and slightly reduced firmness. The 50 mg L−1 treatment substantially enhanced carotenoid content in fruit harvested after one week, while both 25 and 50 mg L−1 treatments increased carotenoid levels in fruit harvested after two weeks. S-ABA treatments increased total phenolics, flavonoids, and antioxidant capacity as compared to untreated control fruit. Our findings indicate that a single preharvest application of S-ABA at 50 mg L−1 effectively accelerates ripening within one week, while the 25 mg L−1 treatment produces significant improvements after two weeks. Accordingly, preharvest spray application of S-ABA could be employed for advancing harvest maturity, colour development, and promoting overall persimmon fruit quality.