Photosynthetic characteristics and growth analysis of Angelica gigas according to different hydroponics methods

The aim of this study was to investigate which hydroponic system is the optimum for growth and photosynthetic characteristics of Angelica gigas during experiment. Angelica gigas ‘Manchu’ were sowed and managed under a growth room chamber. The environmental conditions (temperature 22℃/18℃ (day/night), relative humidity 50-70%, photosynthetic photon flux density (PPFD) 120±6 μmol m -2 s -1 ) were maintained for 3 weeks. Forty eight seedlings with 4-5 leaves were transplanted in deep flow technique (DFT), substrate, and spray culture systems [culture bed: 800 (L) x 800 (W) x 400 mm(H)] under 150±5 μmol m -2 s -1 PPFD provided with fluorescence lamps and cultivated for 11 weeks. At the end of the experiment, fresh and dry weights, leaf lenghth and width, SPAD, root fresh, and dry weights, and root volume of Anglica gigas were measured. Photosynthetic rate of Anglica gigas were measured with portable photosynthesis systems to investigate optimum PPFD, CO₂ concentration, and air temperature conditions. Fresh and dry weights of Anglica gigas grown in substrate were significantly greater than DFT-treated, but there were not significant with spray treatment. Leaf photosynthesis of Anglica gigas showed the tendency to sharply increase as PPFD was increased from 50 to 200 μmol m -2 s -1 . Though CO₂ saturation point was around 1000-1200 μmol mol-1, increase in air temperature from 16 to 26℃ did not quite affect photosynthesis of Anglica gigas. In conclusion, Anglica gigas may be optimally cultivated with a spray culture system as air temperature, PPFD, and CO₂ concentration for environment are controlled at 20±3℃, 150 μmol m -2 s -1 , and around 1000 μmol mol -1 for mass production.