Effect of different ratio of red and blue light emitting diodes on growth and physiological characteristics of two cool-season turfgrass

To solve the problem posed by shade in stadium, the objective of this study was to investigate the effect of the correct red/blue light emitting diodes (LED) light ratio on the of two cool-season turfgrasses (Lolium perenne ‘Monterey No.3’ and Festuca arundinacea ‘Crown’). The amount of catalase (CAT), ascorbate peroxidase (APX), peroxidase (POD), malondialdehyde (MDA), and hydrogen peroxide (H₂O₂), and membrane penetrability, tiller, and growth rate of the turfgrasses were measured. A completed randomized block design was adopted in this study, which included four red/blue light ratio treatments: 3∶1, 5∶1, 7∶1, and 9∶1. The results of this study indicate that turfgrasses planted under 3∶1 and 9∶1 treatments showed worse growth and physiological characteristics, which means excessive blue or red spectrum caused significant damage to turfgrasses. The 7∶1 ratio treatment showed the lowest stress as CAT and APX were more activated and the number of tiller and the growth rate were higher than those in other treatments. In addition, the content of MDA and H₂O₂ and the membrane penetrability were lower compared to those in other treatments, and turfgrass were healthier in general in the 7∶1 treatment.