Effects of Delays between Harvest and 1-Methylcyclopropene Treatment, and Temperature during Treatment, on Ripening of Air-stored and Controlled-atmosphere-stored Apples

Abstract

The effects of temperature during 1-MCP treatment, and the effects of delays of up to 8 d after harvest before treatment, have been investigated using `Cortland', `Delicious', `Jonagold', and `Empire' (normal and late harvest) apple [(Malus sylvestris (L.) Mill. var. domestica (Borkh.) Mansf.] cultivars stored in air for 2 and 4 months and in controlled atmosphere (CA) storage for 4 and 8 months. Fruit were treated with 1 μL·L–1 1-MCP for 24 hours on the day of harvest (warm) or after 1, 2, 3, 4, 6, or 8 days at cold storage temperatures. CA storage was established by day 10. Little effect of temperature during treatment (warm fruit on the day of harvest compared with cold fruit after 24 hours of cooling) was detected. Major interactions among cultivars, handling protocols before 1-MCP treatment, storage type and length of storage were observed. Delays of up to 8 days before 1-MCP treatment either did not affect efficacy of treatment, or markedly reduced it, depending on cultivar, storage type and length of storage. The results indicate that, depending on cultivar, the importance of minimizing the treatment delay increases as storage periods increase.