ETHANOL VAPOR - A NEW ANTI-SCALD TREATMENT FOR APPLES

Superficial scald was controlled on highly susceptible Granny Smith ap ples, grown in New South Wales, by exposing the fruit to evaporating e thanol at 0 or 20 degrees C. To avoid cross contamination of ethanol, the fruit were stored in sealed polyethylene bags (0.05 mm thickness). The ethanol was added at the rate of 0, 0.25, 0.5 or 1.0 g fruit(-1) to five small cups each containing 10 g vermiculite. The bags were the n sealed and the fruit held at 0 or at 20 degrees C for four days befo re storage at 0 degrees C. The addition of 0.5 or 1.0 g ethanol fruit( -1) completely controlled scald in four of the five experiments carrie d out during three seasons. These levels of ethanol substantially redu ced scald in the fifth experiment. Scald was also greatly reduced when 0.25 g ethanol fruit(-1) was used. 90-100% of untreated fruit in all five experiments were affected with scald. There was no fruit injury o r apparent off-flavour after several months storage. Superficial scald was also significantly reduced when fruit was injected, twice, early in storage with 0.3 ml ethanol. In a second experiment scald was reduc ed with a single injection of 0.25 ml ethanol.