This study was conducted to obtain the basic informations for improvement of storability of onion bulbs in cold storage. Onion bulbs were harvested on June 18, 1983. The onion bulbs for drying in the air were kept hanged in the room condition for 0, 5, 30, 45, and 60 days after harvest before cold storage. The onion bulbs for hot air drying were put in the oven (42℃) with aeration system just after harvest and kept for varying length of time before cold storage. In November, 1983, samples of onion bulbs taken from each treatment in storage were planted in sand in the greenhouse to measure the days to sprout. The results obtained are as follows:
1. The number of rots increased in all treatments as storage proceeded. The longer the bulbs were dried in the air, the higher the percentage of healthy bulbs remained.
2. The bulbs hanged in the air for 30 to 60 days before cold storage showed less weight loss than those put in the cold room without drying when only healthy bulbs were measured in the late phase of the storage.
3. Onion bulbs dried with hot air for 12 hours, 12 hours a day for 2 days, and continuous 48 hours before storage showed 2, 2.5, and 3% of weight loss, respectively.
4. Among the hot air drying treatments, the highest percentage of healthy bulbs was obtained by drying the bulbs with hot air for 12 hours a day for 2 days before cold storage.
5. Onion bulbs dried with hot air for 12 hours a day for 2 days and continuous 48 hours before cold storage showed less weight loss than control in healthy bulbs in the late phase of the storage.
6. Samples of onion bulbs from each treatment were taken from the storage in the cold room and planted in sand in the greenhouse on November 5, 1983. Days to sprout of the bulbs dried in the room condition for 30, 45, and 60 days after harvest were significantly less than those for the bulbs put in the storage room 5 days or just after harvest. The difference in days to sprout between hot air dried bulbs and control was not significant.
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