Rapid urbanization and population growth demand sustainable food systems. This study investigated hydroponic vertical farming with LED lighting for Chinese kale (Brassica oleracea var. alboglabra), comparing white LEDs (WL), 20% red + 80% blue (20% RL: 80% BL), and 80% red + 20% blue (80% RL:20% BL). Plants grown under control conditions were assessed at weeks 2, 4, and 6. The 80% RL:20% BL treatment enhanced fresh weight, leaf area, root length, and biomass, while 20% RL:80% BL maximized chlorophyll, anthocyanin, and phenolics. Leaf number and quantum yield remained similar, though stress was evident. The findings of this research highlight red-dominant light for growth and blue-dominant light for phytochemical enrichment.
Singh et al. (2026) studied this question.