Effects of elevated CO₂ and 1-methylcyclopropene on storage-related disorders of Ontario-grown Empire apples

Abstract

Deyman, K. L., Chiu, G., Liu, J., Brikis, C. J., Trobacher, C. P., DeEll, J. R., Shelp, B. J. and Bozzo, G. G. 2014. Effects of elevated CO 2 and 1-methylcyclopropene on storage-related disorders of Ontario-grown Empire apples. Can. J. Plant Sci. 94: 857–865. The impact of 1-methylcyclopropene (1-MCP) application on CO 2 -induced physiological injury in Empire apple fruit during controlled atmosphere storage was assessed over a 3-yr period using an experimental design involving multiple treatment replicates. Fruit harvested at optimal maturity from one or two orchards were treated with or without 1 µL L −1 1-MCP, then chilled at 0 or 3°C under various CO 2 partial pressures (5, 2.5 or 0.03 kPa CO 2 ) in the presence of 2.5 kPa O 2 for up to 46 wk using a split-plot design. Fruit were sampled periodically for assessment of flesh browning and external peel injury. The maximal incidence of external CO 2 injury varied from 15 to 100% over the 3 yr, and the most rapid development of this disorder was evident at 5 kPa CO 2 . The incidence of external CO 2 injury as a function of storage time was influenced by orchard location and storage temperature. Moreover, the incidence of flesh browning at 0°C and 5 kPa CO 2 was influenced slightly by orchard; this disorder was never higher than 30%, and the impact of elevated CO 2 was inconsistent across years. Notably, there was no evidence for negative effects of 1-MCP on the incidence of storage-related disorders.