Improved Fruit Color, Quality, and Shelf Life of `Pink Lady' Apples with Preharvest Application of Aminoethoxyvinylglycine (AVG) in Combination with Ethephon

Abstract

The effects of preharvest application of AVG and ethephon alone, or in combinations, on color development, fruit quality and shelf life were tested in `Pink Lady' apples (Malus domestica Borkh.) in Western Australia during 2002.The experiment aimed at improving color without adversely affecting fruit quality at harvest and after long term cold storage. Treatments included 124.5 g·ha-1 AVG only [148 Days after full bloom (DAFB)]; 280 g·ha-1 ethephon only (148 DAFB); AVG (148 DAFB) followed by ethephon (166 DAFB); and control. Fruit were evaluated for color development, internal ethylene concentration (IEC) and quality at commercial harvest(181DAFB) and 45, 90, and135 days after cold storage (1 °C ± 0.5 °C). At harvest, ethephon with or without AVG significantly (P ≤ 0.05) improved red blush and total anthocyanin in fruit skin. AVG+ethephon treated-fruit had higher total anthocyanin and TSS compared to AVG alone and control fruit. There were no significant differences among different AVG and ethephon treatments for fruit firmness and IEC. During different storage periods, fruit treated with AVG alone and AVG+ethephon had significantly lower IEC compared to fruit treated with ethephon only and the control, however the interactions between treatments and storage periods were not significant for fruit firmness. AVG + ethephon and ethephon alone did not significantly affect fruit color during different storage periods, which showed that the subsequent ethephon spray on AVG-treated fruit had overcome the inhibitory effect of AVG. Our experimental results showed that application of AVG followed by ethephon improved color in `Pink Lady' apples without compromising fruit quality including firmness during extended cold storage.