Preharvest 1-methylcyclopropene delays fruit maturity and reduces softening and superficial scald of apples during long-term storage

Three experiments were undertaken to evaluate the effects of different preharvest 1-methylcyclopropene (1-MCP) spray treatments on apple (Malus x domestica Borkh.) fruit maturity at harvest and quality after long-term storage in a regular atmosphere or controlled atmosphere (CA). Trees were sprayed within 7 days of the anticipated harvest date (H) and fruit for long-term storage were sampled at either H in the case of 'Law Rome' or at harvest dates that were delayed by up to 21 days (H + 21) in the case of 'Golden Delicious' and 'Law Rome'. Preharvest 1-MCP sprays within 7 days of H reduced fruit drop, internal ethylene concentration, and starch index and reduced firmness loss during long-term storage of fruit at delayed harvest dates but had only minor effects on fruit maturity at H. Preharvest 1-MCP sprays reduced the incidence of superficial scald on 'Law Rome' apples more effectively than either diphenylamine or CA storage. Application of 1-MCP within 7 days of H may be used to delay harvest date, thereby allowing continued fruit growth without a concomitant advance in fruit maturity and to reduce firmness loss and superficial scald during long-term storage both for normal and delayed harvests.