Abstract
This report is concerned with the effects of storage temperature or humidity upon the occurrence of Hassaku oleocellosis and also with the results of several treatments tested for the prevention of oleocellosis.
1. The injury of Hassaku fruits caused by oleocellosis was far more slight in the storage room in case of the low temperature (5°C) storage immediately after picking at the end of December than in the storage at natural room temperature, but oleocellosis occurred severely at the period from March to May shortly after putting out of fruits from the storage room of low temperature, and this injury after storage was more severe in April than in March.
2. When the air temperature is low after storage, the injury is only slight even in the later season, and on the other hand the injury became severe when fruits were kept at high temperature (25°C) immediately after picking in December, or after short period storage in January.
3. Immediately after putting out from the storage room of low temperature, fruits were kept at the controlled conditions which were combinations with 3 levels of temperature (5°C, 15°C, 25°C) and 2 levels of relative humidity (61-86%, 91-100%). Fruits kept at high temperature and low humidity were apparently more susceptible than those at low temperature and high humidity, and the effect of temperature seemed to be more dominant than that of humidity.
4. The storage room temperature was maintained at 3 levels (10°C, 15°C, 20°C) during 4 days just before putting out of fruit from the storage room, but these treatments were not effective at all for the prevention of oleocellosis occurring after storage. On the contrary, a remarkable decrease of occurrence of Hassaku oleocellosis was seen, putting out of fruits after the storage temperature (5°C) had been hightened to 10°C at the rate of 1°C a day, But a sufficent effect was not always seen with various conditions of temperature after putting out of fruits.
5. The above mentioned results suggest that the occurrence of oleocellosis is probably due to the great difference between the air temperature after storage and the fruit temperature in storage rather than to the length of storage period.
6. For the purpose of the prevention of oleocellosis, the effects of several treatments applied to fruits were studied immediately after putting out from the storage room of low temperature. These treatments are bagging with Polyethylen film, Wax coating, dipping, with O. E. D (5%), Stop-scald (0.2%), Metrose (0.5%) or coating of Acrylic acid resin. Consequently the Wax and Acrylic acid resin are noticeably effective for the control of oleocellosis and these treatments seems to be worthy for practical use.
