Influence of preharvest environmental conditions and postharvest relative humidity on the appearance of orange peel disorder in sweet cherry during fruit development and storage

Orange peel, a physiological disorder, has been reported in Chilean sweet cherries (Prunus avium (L.) L.) after 35-45 d under modified atmosphere packaging (MAP).The ontogeny of the disorder is unknown, and preharvest factors have not been thoroughly investigated.This study involved two experiments to elucidate the association between environmental factors and the incidence of the orange peel disorder.In the first experiment, plant water potential, fruit position on the tree, relative humidity (RH), and radiation of sweet cherry trees were studied in 'Regina', 'Kordia', and 'Lapins'.The second experiment focused on the interaction effect of heat during fruit development and the RH during storage in 'Lapins'.The first experiment showed no clear response of orange peel incidence to natural variations in air temperature, vapor pressure deficit, and transmitted solar radiation (PPFD) within trees.However, significant differences in the incidence, severity, and timing of the disorder detection were observed among cultivars.In 'Lapins', orange peel disorder began before harvest in the green stage, 33.7 %, while 'Regina' and 'Kordia' showed negligible incidences of 1.25% and 0%, respectively.At postharvest, no differences were found among tree sections, either in incidence or severity of the disorder.For the second experiment, no differences in incidence were found in heated fruit during preharvest or postharvest RH treatments.However, it was observed that the higher the RH (100%), the lower the severity index (3.6)was for the orange peel disorder.The high incidence of the disorder during postharvest under natural or induced environmental conditions in the three cultivars evaluated demonstrates that RH mainly affects the orange peel disorder.