Impact of LED Combinations and Light Intensity on Growth and Yields of Wasabi

This study examines the effects of different LED light spectra and intensities on the growth, photosynthetic performance, and biochemical composition of the ‘Daruma’ cultivar of wasabi (Eutrema japonicum). The primary objective is to enhance the efficiency of indoor cultivation techniques for this economically significant crop. Wasabi seedlings were cultivated under LED lighting with four light intensities (35, 60, 90, and 140 µmol m⁻2 s⁻1) and three spectral combinations: red and white (1:1); red, white, and blue (1:1:1); and white. Growth parameters, including plant height, petiole length, leaf number, and yield metrics such as fresh weight and leaf area, were measured alongside photosynthetic activity and chemical analysis of glucosinolate levels. The results indicate that higher light intensities (particularly 140 µmol m⁻2 s⁻1) greatly enhance overall plant biomass, with red-dominant spectra promoting more significant growth and glucosinolate accumulation, a key secondary metabolite in wasabi. Lower intensities increased chlorophyll content and produced darker green foliage but decreased growth performance. Additionally, the interaction of red and blue light spectra with increased light intensity suggests that specific red light conditions are optimal for maximizing wasabi biomass and biochemical yield. These findings contribute valuable insights for optimizing light regimes for wasabi and similar shade-adapted crops in controlled indoor farming systems, potentially improving yield and quality in plant factories and supporting the future of indoor farming.