PREHARVEST APPLICATIONS OF ETHEPHON REDUCE SUPERFICIAL SCALD OF FUJI AND GRANNY-SMITH APPLES IN STORAGE

In 1989 and 1990, preharvest applications of 2-chloroethyl phosphonic acid (ethephon) at dosages from 50-400; mg l(-1) were applied to 'Fuji' and 'Granny Smith' apples. In 1989, the greatest reduction in scald after storage on both 'Fuji' and 'Granny Smith', relative to the untreated control resulted from applying 400 mg l(-1) ethephon five weeks before harvest and was 45% and 55% of controls, respectively. On 'Granny Smith' 400 mg l(-1) was also effective when applied three weeks before harvest. In 1990, preharvest applications of ethephon at either 200 or 400 mg l(-1) reduced scald in both cultivars relative to the controls. Ethephon applied six weeks before harvest had no dosage effect on scald reduction after storage. There was no consistent effect on fruit maturity at harvest from any treatment in either year, and no effect on quality of fruit out of storage.