S05 - Session P2 - Evaluation of the effect of difference in growing media on photosynthesis and transpiration functions of ornamental plants

Authors: Jiaxun Hu *, Shuichi Obayashi, Takanobu Inoue, Seitaro Toda, Kotaro Takayama

The current COVID-19 pandemic has urged many people to stay at home for long period. In Japan the demand for ornamental indoor plants was dramatically increased to make our stay-at-home life comfortable because the positive effects of ornamental plants on human mental health are well known. To keep the indoor plants at good condition for longer than several months, we need to know the plant's environmental responses and care for the plants in appropriate way with necessary and sufficient lighting, irrigation, and nutrition. Furthermore, there is a strong requirement for manageable growing media because it is kept in home room. So, the photosynthesis, transpiration, and total conductance of two kinds of indoor ornamental plants, which were grown in two different types of growing medias, were measured and the effects of difference in growing media on the environmental responses of the plants were investigated. Ten plants of Spathiphyllum and the same number of Syngonium were purchased from nursery and used for the experiment. After removing the soil from the root area, all the plants were replanted in two types of growing media, i.e. inorganic medium and soil. After growing in a greenhouse for 3 months, the plants were acclimated to the indoor environment for 1 week and used for the measurement. The closed chamber method was used to measure the photosynthesis and transpiration rate. Chlorophyll content was measured with a SPAD meter, and leaf area was calculated by image analysis. The dry weights of shoot and root were measured after drying at 80 °C for 48 hours. The results proved that the transpiration rate, SPAD value, and shoot/root ratio of Spathiphyllum and photosynthetic rate and SPAD value of Syngonium of inorganic medium were significantly higher than those of soil.