This study was carried out to investigate the effect of cooling treatment of seed bulb and day length on the growth and bulb formation of shallots. Seed bulbs were planted after 4℃ low temperature treatment for 10, 20, 30 and 40 days, respectively, and 8, 12 and 16 hrs of day length was given during the growing period.
1. Early growth was promoted by long day treatment, but with an increment of day length plant height was decreased. Particulary 16 hrs of day length treatment showed marked supperession of top growth.
2. Best plant weight was obtained under natural day length and tillerings were not affected by both treatment, low temperature and day length.
3. Leaf numbers and weight tended to be decreased under long day, and leaf weight under natural day was markedly increased.
4. 16 hrs of long day treatment resulted in acceleration of bulb formation, whereas short day prolonged the vegetative growth and showed little evidence of bulb formation.
5. Growth and bulb formation of shallot was markedly affected by day length, but the effects of 4℃ low temperature treatment of seed bulb were not showen in this experiment.
|