2018 ASHS Annual Conference

In the U.S. Northwest, sweet cherries that are shipped to distant markets are subject to various arrival issues including fruit softening, flavor loss, skin darkening, pitting, splitting, pedicel browning, and decay. The objectives of this study were to develop preharvest calcium (Ca) and gibberellic acid (GA₃), separate or in combination, spray protocols to improve cherry harvest/shipping quality. Six weekly applications of 0.15% Ca were required between pit-hardening and 1-week before harvest (WBH) to increase fruit tissue Ca concentration of ‘Lapins’. Two applications of Ca applied at pit hardening and WBH did not improve tissue Ca concentration compared to the 6-application regime. For 0.15% Ca + 25 ppm GA₃ application, GA₃ was applied a single time, alone or combined with Ca, at pit-hardening, then afterwards Ca was sprayed five weekly to 1 WBH. Soluble solid (SSC), titratable acidity (TA), and fruit diameter at harvest were not affected by the Ca + GA₃ applications, while fruit firmness and tissue calcium content of ‘Skeena’, ‘Lapins’ and ‘Regina’ were significantly increased compared to the alone Ca or GA₃ applications. Ca+GA₃ treatment improved shipping quality by enhancing tissue Ca content, reducing cracking, surface pitting, decay, pedicel browning, skin darkening, and loss of firmness and TA after 4 weeks of cold storage.