IMPROVING STORABILITY OF TAROCCO ORANGES BY POSTHARVEST HOT-DIP FUNGICIDE TREATMENTS

The effectiveness of postharvest water dip, with or without thiabendazole (TBZ) or Kilol DF-100 (DF) fungicide treatments, at 52 degrees C on the keeping quality of 'Tarocco' oranges during two months storage at 8 degrees C and subsequent one week of simulated shelf-life at 20 degrees C was investigated in comparison to water dip with or without TBZ and DF at 25 degrees C. Considerable control of chilling injury and decay occurred both during storage and simulated shelf-life with 52 degrees C water dipping. TBZ fungicide was also effective in disease and disorders control, its efficacy being greatly enhanced when used in hot solution. Beneficial effects were also produced by DF applied alone or in combination with TBZ, but to a lesser extent at 25 degrees C. Respiration rate and ethanol amount in the juice were significantly affected by dip temperature and by treatments, while endogenous ethylene did not. Mean values of electrolyte leakage of flavedo peel discs from fruit dipped at 52 degrees C during storage were significantly lower than those dipped at 25 degrees C. After simulated shelf-life, values tended to level out. No detrimental effects on quality characteristics of fruits occurred as a consequence of prestorage dip treatment in water alone at 52 degrees C or with fungicide solutions.