Storage Temperature and 1-MCP Treatment Affect Storage Disorders and Physiological Attributes of ‘Royal Gala' Apples

‘Royal Gala’ apples [Malus  domestica (Borkh.) Mansf.] can develop postharvest disorders such as flesh browning, senescent breakdown, peeling, cracking, or shriveling during and after cold storage. The objective of this study was to examine the effects of storage temperature and a range of 1-methylcyclopropene (1-MCP) concentrations on fruit quality attributes and incidence and severity of postharvest physiological disorders during and after cold storage.  Storage temperature significantly affected internal ethylene concentration (IEC), fruit circumference, and cortex color. The 1-MCP treatment resulted in significant effects on fruit quality attributes and severity of physiological disorders, regardless of storage temperature.  Incidence and severity of diffuse flesh breakdown, shriveling, cracking, and peeling were highest in control fruit stored at 3 °C but radial stem-end flesh breakdown only appeared in 1-MCP treated fruit.  Incidence of radial stem-end flesh breakdown was highest following storage at 0.5 °C compared with 3 °C.  1-MCP treatment prior to storage had the most influence on disorder incidence/severity or quality attributes while treatment concentration of 1-MCP was not significant. Overall, the results indicate that 1-MCP treatment can reduce the incidence of ‘Gala’ diffuse flesh breakdown but may enhance sensitivity to radial stem-end flesh breakdown when fruit are stored at 0.5 °C or 3 °C.  Evidence supports that incidence of diffuse flesh breakdown and radial stem-end flesh breakdown are influenced differentially by storage temperature or by 1-MCP treatment, respectively indicating they may be different disorders.