Assessment of ethylene production by apple cultivars in relation to commercial harvest dates

The potential use of ethylene production as a maturity index for New Zealand‐grown apple cultivars was assessed by following the timing of ethylene production from samples of ‘Cox's Orange Pippin’, ‘Royal Gala’, ‘Golden Delicious’, ‘Delicious’, ‘Braeburn’, ‘Fuji’ and ‘Granny Smith’ in relation to their commercial harvest periods. Each cultivar showed a distinct pattern of ethylene production, and the relationship between ethylene production and the timing of the current harvesting period varied with cultivar. The suitability of using evacuated vials for collecting ethylene gas samples from enclosed apple fruit and transporting them to a laboratory for analysis was also examined. Gas samples held in the vials maintained a stable ethylene concentration for up to 4 days.