Application of Calcium Chloride at Different Phenological Stages Alleviates Chilling Injury and Delays Climacteric Ripening in Peach Fruit during Low-Temperature Storage

Owing to the high degree of perishability of the fruit, the peach industry faces serious challenges tackling physiological disorders, microbial/chemical decay, and the suboptimal quality of the fruit during and following cold storage. The present study was aimed to investigate the effects of spray applications of calcium chloride (CaCl2) at various physiological stages of fruit growth and development, on ripening, flesh softening, chilling injury (CI) and nutritional quality of peach fruit cv "Flordaking" during low-temperature storage. The aqueous solutions of CaCl2 [0, 1, 2, and 3% (w/v)] were sprayed on peach trees during cell division, pit hardening and cell expansion stages in 2011 and 2012. At commercial harvest, the fruit were hand-picked and were subjected to cold storage at 1 +/- 1 degrees C (RH: 90 +/- 5%) for 6 weeks. The data on CI index and other quality characteristics of the fruit were recorded at harvest and then weekly for up to 6 weeks. The results showed that the pre-harvest spray application of CaCl2 substantially reduced the incidence of chilling injury (CI) and delayed climacteric ripening seemingly by lowering the rates of ethylene production and fruit softening during storage as compared to control, regardless the doses of CaCl2 and its application time, however higher doses of calcium chloride proved to be toxic causing blemishes on the surface of "Flordaking" peaches. In conclusion, pre-harvest spray application of CaCl2 @ 1% may be a successful production management tool to maintain the quality and to extend storability of peach fruit during cold storage.