ASHS 2015 Annual Conference
Controlled Atmosphere and Dynamic CA-Chlorophyll Fluorescence Storage of 'McIntosh' and 'Delicious'
Controlled Atmosphere and Dynamic CA-Chlorophyll Fluorescence Storage of 'McIntosh' and 'Delicious'
Wednesday, August 5, 2015
Napoleon Expo Hall (Sheraton Hotel New Orleans)
Fruit from four orchards of ‘Delicious’ from western NY and ‘McIntosh’ from the Champlain region of NY were harvested, untreated or treated with 1-methylcyclopropene (1-MCP) and kept in controlled atmosphere (CA) and dynamic CA-chlorophyll fluorescence (DCA-CF) storage for up to 8 months. O2 levels for ‘Delicious’ were kept 0.2% above the fluorescence-derived low oxygen limit levels detected at 0.4% (0.5 oC) and 0.9% for ‘McIntosh’ (2 oC). ‘Delicious’ apples had 0 to 90% water core at harvest. After 4 months in storage, there was slightly higher firmness in the latter if fruit were not treated with 1-MCP, but otherwise few differences between CA and DCA-CF-stored fruit. Water core was present in fruit from two orchards that had water core at harvest, and at higher levels in DCA-CF-stored samples, although much lower than at harvest. After 8 months, DCA-CF ‘Delicious’ had less flesh browning than those in CA storage. Firmness was slightly lower in two of the orchards in CA; this was not observed, however, in fruit stored in DCA-CF or treated with 1-MCP. DCA-CF-stored ‘McIntosh’ had fewer disorders and were more firm after 4 storage months compared with those in CA conditions. Vascular and core browning developed by 8 months, and were observed at similar levels in both CA and DCA-CF environments. Lowest incidences of internal and external CO2 injury occurred in DCA-CF-stored ‘McIntosh’. The DCA-CF treatment often reduced senescent breakdown in the absence of 1-MCP, but in one orchard it was worse in DCA-CF than in CA, 1-MCP had a greater effect on firmness and quality while DCA-CF reduced certain disorders. For both cultivars, a combination of DCA-CF and 1-MCP often resulted in the greatest number of high quality fruit.