Different light spectra and intensity level effects on vegetative growth and antioxidant content of coriander

The main purpose this paper is to study effects of red and blue colored lighting and light intensity on coriander growth. LEDs tubes were constructed using three light spectral combinations with different light ratios of red (660 nm) and blue (447 nm). Light ratios were 10:4, 10:2 and 10:1 with two photosynthetic photon flux density (PPFD) values of 150±10 and 250±10 µmol m^‑2 s^‑1. Daylight was used as the control treatment. Findings showed coriander growth characteristics cultured under LED lights is enhanced compared to a daylight environment. Using LED with higher PPFD resulted in better growth parameters. At a PPFD value of 150 µmol m^‑2 s^‑1, the high red per blue ratio increased height, number of leaf and shoot of coriander compared with the lower red per blue ratio. However, the low red per blue ratio at PPFD value of 250 µmol m^‑2 s^‑1 increased number of leaf and shoot of coriander. A greater dry weight was obtained when grown under the LED light source compared to coriander grown under a daylight environment. In addition, antioxidant activity was increased under the higher blue light levels. However, comparing the antioxidant activity based on a 1-g dry mass, coriander grown under daylight had a higher antioxidant activity compared to all LED light treatments.