Synergistic effect of preharvest treatments on storability of date palm fruit (Phoenix dactylifera L. 'Khenizi')

'Khenizi' is one of the most consumed date fruits in the Arab region specially at Rutab stage. With an increasing market demand of this Rutab date, preserving its quality from farm to the market has become a great challenge. The present study used different combinations of natural elicitors as preharvest treatments: chitosan (Ch) 1% single or combined with salicylic acid (SA) 2 mM and calcium chloride (Ca) 3% to investigate the physiological changes in fruits during 10 weeks of cold storage. Total soluble solids (TSS) was lower in Sa, Ch+SA+Ca, Ch+Ca treated-fruit as compared to the control fruits and other treatments. Similarly, SA treated fruits showed the least decay after 10 weeks of storage. The total phenolics (TPC), tannins (TTC) and flavonoids (TFC) content were found high in the Ch+SA+Ca treatment followed by Ch+SA and Ch+Ca by the end of the storage. Antioxidant activities were found in all treatments, with significantly higher effect in Ch+SA+Ca, Ch+SA and Ch+Ca compared to control and other treatments. Our results suggested that the use of elicitor combinations to increase the shelf life of date fruit during cold storage by preserving its quality and reducing spoilage may present a promising strategy.