Increased Antioxidants of Agastache rugosa by the Night Interruption Time

The objective of this study was to determine the proper night interruption of photoperiods and dark periods for accumulating bioactive compounds of Agastache rugosa without decreasing plant growth.Five-week-old seedlings were transplanted in a DFT system with white LEDs. A. rugosa was treated with night interruption time treatments of 18:1:2:3, 18:2:2:2, 18:3:2:1 (light:dark:light:dark), and 20:4 (control) for 4 weeks.There were no significant differences except for leaf length, leaf width, and the number of flowers.The content of antioxidants in the shoot of A. rugosa was high in tilianin and acacetin, and the content of rosmarinic acid (RA) was significantly higher in the underground part.The RA content per dry weight of A. rugosa was 47.92 and 51.46% higher than that of the control in 18:1:2:3 and 18:2:2:2, and tilianin and acactin per dry weight were significantly higher in 18:3:2:1.There was no significant difference in growth due to the same day light integral, but 18:2:2:2 showed high total polyphenol contents.Therefore, it is thought that the effect of increasing secondary metabolites of A. rugosa without degradation of growth can be expected through night interruption treatment in plant factory cultivation systems using artificial light.