Background: Epilobium hirsutum L. is designated as an endangered plant in South Ko- rea located in Asia, due to the destruction of its habitats through the development of wet- lands. Therefore, in this study, in order to find a light condition suitable for the growth and ecophysiological responses of Epilobium hirsutum L., those of this plant under treatment with various light qualities in a smart farm were measured.
Results: In order to examine the changes in the physiological and growth responses of Epilobium hirsutum L. according to the light qualities, the treatment with light qualities of the smart farm was carried out using the red light: blue light irradiation time ratios of 1:1, 1:1/2, and 1:1/5 and a red light: blue light: white light irradiation time ratio of 1:1:1. As a result, the ecophysiological responses (difference between leaf temperature and atmo- spheric temperature, transpiration rate, net photosynthetic rate, intercellular CO₂ partial pressure, photosynthetic quantum efficiency) to light qualities appeared differently ac- cording to the treatments with light qualities. The increase in the blue light ratio increased the difference between the leaf temperature and the atmospheric temperature and the photosynthetic quantum efficiency and decreased the transpiration rate and the inter- cellular CO₂ partial pressure. On the other hand, the white light treatment increased the transpiration rate and intercellular CO₂ partial pressure and decreased the temperature dif- ference between the leaf temperature and the ambient temperature and photosynthetic quantum efficiency.
Conclusions: The light condition suitable for the propagation by the stolons, which are the propagules of Epilobium hirsutum L., in the smart farm, is red, blue and white mixed light with high net photosynthetic rates and low difference between leaf temperature and atmospheric temperature.

Keywords: artificial light, light stress, photosynthesis, rhizome, stolon, vegetative propagation, wetland plant