Effect of Gibberellic Acid and Ethephon on Ascorbic Acid Content And Ascorbic Acid Oxidase Activity of Redhaven Peaches

Abstract

Redhaven peaches from trees treated with foliar applications of 100ppm gibberellic acid or 150ppm ethephon were analyzed for reduced and total L-ascorbic acid content. Reduced ascorbic acid levels were higher in treated fruit when compared to non-treated, when oxidative enzymes of the tissue had been activated by macerating the flesh. No significant differences, however, were found in either reduced or total ascorbic acid content of intact tissues. No ascorbic acid oxidase activity could be detected.It is suggested that ascorbic acid functions as a reducing agent in the fruit, retarding the effects of the oxidative enzymes. Any effect of growth regulators on the activity of enzymes such as polyphenoloxidase, might be reflected in increased quantities of reduced ascorbic acid in tissue which has undergone physical damage.