1a.Objectives (from AD-416):
The project aims to identify roles of ethylene action in development of apple and pear fruit physiological disorders. Research will focus on identification of key physiological events that lead to development of internal and external CO2 injury (apple) and chilling injury (apple and pear).

1b.Approach (from AD-416):
Materials to stimulate (ethephon) or reduce (1-methylcyclopropene) ethylene production and activity, respectively, will be applied to apple and pear fruit at various rates and selected intervals prior to and/or after harvest. Physiological (volatile production, respiration, ethylene-related metabolites) and horticultural (color, weight, firmness, acidity,sugar content) indicators of fruit development will be determined using fruit sampled at various intervals at harvest and after storage. All evaluations will be conducted at the Tree Fruit Research Laboratory in Wenatchee.

3.Progress Report:

This project relates to objective 1 of the associated in-house project which seeks to identify factors that influence postharvest fruit quality and development of market limiting physiological disorders. Studies initiated in 2012 will characterize metabolic impacts of compounds that enhance or inhibit ethylene responses of apple and pear fruit during storage in controlled atmospheres that induce CO2 injury.