Epicuticular changes in response to ethylene regulation in apple
2012 Annual Report
1a.Objectives (from AD-416):
Determine interrelationship between controlled atmosphere (CA), relative humidity (RH), and SmartFresh (MCP) on apple cuticle structure, function and disorder.
1b.Approach (from AD-416):
Previously, work done at the ARS laboratory in Wenatchee indicated preharvest treatments that increased ethylene production in ‘Granny Smith’ apples also increased fruit epicuticular wax production during storage. Similarly, treatments that reduced postharvest ethylene production were associated with a delay in fruit epicuticular wax production during storage.
Ethylene is implicated in apple epicuticular wax production. Wax production is necessary for “healing” the microcracking associated with normal fruit growth and cuticle expansion. Degree of microcracking “healing” by the time storage conditions are achieved influences fruit cuticle water vapor permeance, which, together with ambient conditions, establishes desiccation potential of fruit in storage. Moisture loss of fruit in storage followed by rewetting during water-based fruit processing may be implicated in cuticle cracking around lenticels, and disorders associated therewith.
This project will focus on the interrelationship of fruit ethylene production, fruit cuticle water vapor permeance and ambient water vapor pressure during storage and the impact these have on physiological storage disorders.
This project relates to objective 3 of the associated in-house project which seeks to identify factors that influence postharvest fruit quality and development of market-limiting physiological disorders. Experiments were conducted on ‘Lady Alice’ apples (a sport similar to the cultivar ‘Pink Lady’) to examine the effect on quality of an inhibitor of fruit ripening applied post harvest, during storage, impact of oxygen (O2) level during storage, and post-harvest soap/wax treatment. Fruit stored in air had the lowest incidence of lenticel breakdown and black lenticel. A summary of results to date suggest ‘Lady Alice’ apples treated with an ethylene action inhibitor then stored in air at 33 degress Farenheit have acceptable quality through 6 months.