2019 Volume 47 Issue 2 Pages 95-104
Perennial ryegrass (Lolium perenne L.) turf was grown under light-emitting diode (LED) lamps at different color temperatures (5,000 K [dominant wavelength: 450 nm] and 2,700 K [dominant wavelength: 600 nm]) for different irradiation times (8 and 4 h/day). Plants height were recorded, and all plants were clipped to a height of 20 mm weekly. The plants were harvested at 28 days after treatment. The dry weights of the clippings, tops, and roots, numbers of tillers and leaves, and degree of reddening at shoot base were measured. The total dry weight significantly increased, as did the photosynthetic photon flux density. The total dry weight was four times heavier under supplemental lighting (5,000 K 800 μmol 8 h) than under control conditions (5,000 K 0 h and 2,700 K 0 h). Significantly greater vertical elongation was noted at 2,700 K than at 5,000 K, indicating that supplemental lighting at 5,000 K suppresses upward elongation. The numbers of tillers and leaves were greater at 5,000 K, indicating accelerated growth and shortened curing. These data imply that 5,000 K supplemental lighting is effective for forming dense turf and early recovery from trampling and other damage.
