USE OF 1-MCP TO REDUCE THE REQUIREMENT FOR REFRIGERATION IN THE STORAGE OF APPLE FRUIT

The growth regulator 1-methylcyclopropene (1-MCP) is a vapor under physiological conditions and acts by inhibiting the binding of the hormone ethylene to its binding site and a single exposure can temporarily render plant material insensitive to ethylene when applied at the parts-per-billion level. Apple fruit were harvested one week prior to the climacteric (harvest 1), at the onset of the climacteric (harvest 2) and one week after the onset of the climacteric (harvest 3). Fruit were given treatments with 0.7 ppm 1-MCP on a once-per-week, once-per-two weeks, once-per-month and once-per-year basis or were left untreated and stored at 0, 5, 10, 15, and 20°C. In terms of reduced softening, earlier harvested fruit were more responsive to the 1-MCP treatment and the efficacy of 1-MCP was enhanced by repeated application. 1-MCP effectively prevented softening at all temperatures relative to the controls, however, as temperature decreased, the benefits of 1-MCP application became less pronounced. Decay was a significant problem for fruit stored at 15 and 20°C storage temperatures. Roughly 30 to 60% of the fruit were lost to decay in the first 100 days of the study. 1-MCP application reduced, but did not prevent decay. Storage of 1-MCP treated apple fruit at elevated temperatures will be limited to relatively short durations (< 50 days) without some means of controlling decay in storage.