EFFECT OF ETHREL pH ON THE SHELF LIFE AND INCIDENCE OF SCALDING OF “ANNA” APPLE FRUITS

Enhancing color formation in “Anna” apple is desired by producers and customers. Preharvest application of Ethrel has been known to increase anthocyanin formation in climactreric fruits such as apples while shortens the shelf life and storability. In this study, Ethrel pH was modified in an attempt to examine its effect on the shelf life and the incidence of scalding in Anna apples. Thus, fruits were sprayed at about 10% coloration by Ethrel at 250 and 500 ppm (at pH 3.2 and 6.0) in addition to the control. The surfactant Triton-B was added to all treatments at 0.05% (v/v). Fruits were harvested after 12 days of spray during the two seasons of study 2005 and 2006. Ethrel applications did not cause a reduction in fruit weight at harvest while led to a significant increase in anthocyanin content whether at pH 3.2 or 6.0 with the two used concentrations. Furthermore, Ethrel treatments at pH 6.0 in general were not able to retard the loss of firmness by the end of the 6 days on the shelf. However, this study revealed that incidence of soft scald by the end of shelf test was associated with advancement in ripening and not to calcium deficiency as most apple producers believe. Scalding in fruits harvested from the same orchard occured only in Ethrel-treated fruits and did not occur at all in the control fruits. J.Agric.&Env.Sci.Alex.Univ.,Egypt Vol.5 (1)2006 22