Electrolyte Leakage from Daminozide-treated Apples Held in Air, Low-pressure, and Controlled-atmosphere Storage1

The permeability of the flesh of ‘McIntosh’ apples ( Malus domestica Borkh.), as measured by electrolyte leakage, appeared to follow a phasic pattern with aging. A phase of initial reduction of permeability preceded a large increase, then there was a slight transient decrease in permeability, and finally a slight increase. Field treatment with butanedioic acid mono (2,2-dimethylhydrazide) (daminozide), early harvest, controlled atmosphere and low-pressure storage as well as a low storage temperature (0.5 vs. 3.5°C) favored a reduction of permeability. The effect of low-pressure storage on the reduction of permeability appeared to be due to a delay of ripening as evident in delayed C 2 H 4 production; that of controlled-atmosphere storage seemed to be due to some effect of the atmosphere other than one upon ripening, because the fruit produced C 2 H 4 upon removal from storage.