|Budget Amount *help
¥9,300,000 (Direct Cost : ¥9,300,000)
Fiscal Year 1999 : ¥1,800,000 (Direct Cost : ¥1,800,000)
Fiscal Year 1998 : ¥3,000,000 (Direct Cost : ¥3,000,000)
Fiscal Year 1997 : ¥4,500,000 (Direct Cost : ¥4,500,000)
Based on major factors of flowering, Higuchi et al. (1993) categorized ornamental plants into three types, namely, Photoperiodicity-, thermoperiodicity-, and vegetative reproductive growth periodicity-type (VR). This categorization is outstanding and able to classify various ornamental plants according to the developmental phases and flower-inducing factors. There are a large number of published works about growth habits and flowering control of ornamental plants, however, most of them are not useful for Higuchi et al. ' s categorization because of lacking data on developmental phases.
Our studies added several ornamental plants to Higuchi et al.' s categories and also showed that their categorization did not cover the following plants: (1) Anemone (No qualitative requirements for germination, flower bud differentiation and flowering. Low temperature of 10℃ for 4-5 weeks increased the number of cut flowers and improved flower quality) ; (2) Madagascar jasmine (Flower bud differentiation
was stimulated by intermediate temperature, but inhibited by high temperature. Flower bud development was stimulated at high temperature. At low temperature it was inhibited by long days, and strongly inhibited by short days. A day-neutral plant) ; (3) Sucuteraria baicalensis (No qualitative requirements of photoperiod and temperature for flower bud differentiation and flowering) ; (4) Heliopsis helianthoides (No requirements of temperature for flower bud differentiation and flowering. A qualitative long-day plant) ; and (5) Campanula lactiflora (No qualitative low temperature requirements for flower bud differentiation and flowering. A qualitative long-day plant).
Takeda (1999) has proposed different and more easily applicable categorization to practical culture, Which is based on the responses of ornamental plants to the environment rather than on the developmental phases chageable with environmental conditions. In his categorization ornamental plants are grouped by the vegetative growth periods, flowering times, and effects of temperature and photoperiod on flowering.
In any case, the definition of technical terms such as vernalization and dormancy is prerequisite to categorize ornamental plants. Less