Abstract
1. By chilling 4-year-old plants with large tuberous roots of spring-blooming cultivars, two to three cut flowers were harvested per plant in late December, whereas, the same treat-ment with 2-year-old plants with small tuberous roots yielded only one flower per plant. The flower quality of the 4-year-old plants was equal to or slightly better than that of 2-year-old plants.
2. To force flowering by early December, winter-blooming cultivars were chilled for a short period. The flower quality of the chilled plants was much better than that of the unchilled ones.
