Ethylene Emission of Apples Treated with 1-Methylcyclopropene During Storage

The effect of post-harvest application of 1-methylcyclopropene (1-MCP) on ethylene emission in early-winter apple (cv. ‘Calville’), winter (‘Gloster’, ‘Golden Delicious’ and ‘Jonagold’), and late-winter cultivars (‘Granny Smith’, ‘Idared’ and ‘Reinette Simirenko’) w as investigated. The fruits were picked at a commercial harvest time and half of them were treated with 1-MCP (‘SmartFresh™’ 0.068 gm^-3) for 24 h at 5 °C. Then both groups of apples were placed in a common storage at the temperature of 2 °C. The intensity of fruit ethylene emission (rate of ethylene production) was measured and 1 -MCP inhibition index was calculated. During storage, activity of ethylene emission by control apples of ‘Calville’ and ‘Golden Delicious’ showed typical climacteric pattern, while the intensity of ethylene emission of apples of other cultivars only increased gradually. The change of ethylene activity of early-winter apple cv. ‘Calville’ and winter cv. ‘Jonagold’, both treated with 1-MCP after harvest, had exponential character, especially actively increasing after 3 months of storage. At the same time ethylene emission of 1 -MCP treated fruits of other cultivars changed steadily to a low level and was effectively suppressed during the whole 6-month period of storage in normal atmosphere. The value of inhibition index of fruits treated by 1-MCP confirmed the consistent restoration of the ability to ethylene synthesis and thus to post-harvest ripening of some apples cultivars.