Garlic seed bulbs of two ecotypes, Seoshin(northern) and Namhae (southern), were planted after 4℃ treatment for 25 and 50 days respectively, and kept them warm in the plastic film house from March. At the same time, night interruption (30, 60 and 120 min.) and supplemental lightening (60 and 120 min.) were treated during the same period, and was given 60 min. night interruption with combination of different light intensity (50, 150, 300 and 500 lux).
1. Sprouting and early growth of Seoshin were accelerated by low temperature treatment, but those of Namhae not affected.
2. With an increment of the period of low temperature and the length of night interruption and supplemental lightening (light treatment) treatment, leaf numbers tended to decrease while plant height was increased with increment of light treatment.
3. Bolting was promoted and the period of bolting were shortened 2-3 days in Seoshin and 1-2 days in Namhae by extending light treatment.
4. Bulbing was accelerated with longer low temperature and light treatment. Especially, Seoshin when treated by 50 days of low temperature and 120 min. night interruption showed the most significant increase in bulb weight, while those of Namhae were decreased.
5. Seoshin showed tendency of increase in occurance of secondary growth with shorter light treatment and longer low temperature. Particulary it reached a maximum secondary growth under the natural photoperiod with 50 days low temperature. Regardless of treatments Namhae showed no secondary growth but complete bolting.
6. Night interruption at mid-night was more effective than supplemental lightening to the promotion of growth and bulbing of garlic, and its effect was increased with the higher light intensity and 150 to 300 lux were appeared to be the practical range.
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