Institute of Vegetable and Floriculture Science, NARO

Physiology and Cultivation Unit

In addition to comprehensive analysis of the physiological mechanisms associated with growth and flowering, we are developing technology to stably produce cut flowers by means of controlling light environment and managing temperature and humidity. Our target for this research are major ornamental plants such as chrysanthemums etc. In addition, we are clarifying the cultivation conditions that can enhance such qualities as flower color and shelf life of cut flowers.

Our major themes are as follows:
(1) Analysis of the influence of environmental factors such as temperature on flowering. Flowering defect caused by high temperature in summer is a major problem in production for highly valuable flowers such as chrysanthemum. In order to mitigate this problem, we are working on the elucidation of influence of environmental factors such as temperature on the physiological mechanism which makes the flower bloom using molecular biology techniques.
(2) Development of production technology to prevent discoloration in major cut flowers. In some flowers, when the temperature of the cultivation environment becomes high, the color of the flower becomes poor. Hence original value of cut flower is also affected. In order to enable annual production with stable quality, we will develop an efficient cultivation technology to prevent this problem.
(3) Development of high-quality floriculture production technology based on physiological mechanism etc. While domestically produced cut flowers are required to improve their competitiveness, quality such as longevity is emphasized during the usage of the consumers. Therefore, we are clarifying the relationships between water status of crops and physiological condition such as photosynthesis. We are also developing control technology for cultivation environments that improves quality such as longevity.
(4) Construction of stable production system of chrysanthemums that corresponds to internationalization. With the aim of strengthening competitiveness against imported chrysanthemums and recovering the domestic market share, we are collaborating with wholesalers / retailers to propose the quality and standard of cut flowers and efficient production methods that meet the current demand of the market.


Unit Leader

Katsuhiko INAMOTO

Unit Members



Yoshihiro NAKANO