Climate conditions and spray treatments induce shifts in health promoting compounds in cherry (Prunus avium L.) fruits

Effects of repeated sprayings expected to affect phenolic, anthocyanin, carotenoid and ascorbic acid content in ‘Skeena’ and ‘Sweetheart’ cherries were observed during two years (without addition of calcium (Ca) in 2015, and with Ca in 2016). A shift in phytonutrients, with higher phenolic and carotenoid- and lower ascorbic acid content was observed when comparing Ca and the control (water) treatments in 2016 compared to 2015. Higher radiation, higher temperatures and less precipitation in 2015 compared to 2016 likely contributed to this shift. Gibberellic acid (GA₃), abscisic acid (ABA), salicylic acid (SA) and glycine betaine (GB) sprays increased anthocyanin content in 2015 and for ‘Skeena’ cherries in 2016. GA₃ and GB induced lower carotenoid content for ‘Skeena’- in 2015 and for ‘Sweetheart’ cherries in 2016 and lowered ascorbic acid content for ‘Sweetheart’ cherries. GA₃ sprays induced the largest changes, increasing anthocyanin- (42 %), lowering carotenoid (19 %) and ascorbic acid content (53 %) compared to control. Ascophyllum nodosum, one of the novel spray treatments next to GB, appears to induce an effect opposite to GB, increasing carotenoid and ascorbic acid, but lowering phenolic content. Whether these phytonutrient shifts, due to climate conditions or to spray treatments, are beneficial to consumer health is unclear.