2014 ASHS Annual Conference
18747:
The Effect of Multi-wavelength Light-emitting Diode Lighting on the Growth Response of Leaf Lettuce at Different Stages
18747:
The Effect of Multi-wavelength Light-emitting Diode Lighting on the Growth Response of Leaf Lettuce at Different Stages
Wednesday, July 30, 2014
Ballroom A/B/C (Rosen Plaza Hotel)
This study researches the effect of a combination with light-emitting diode (LED) of different wavelength-bands on the growth response of leaf lettuce (Lactuca sativa var crispa) at different growth stages. The wavelength-bands consist of red (R; 623-673 nm)-, Light red (Lr; range: 599-644 nm)-, blue (B; range: 427-478 nm)-, Light-blue (Lb; range: 435-489 nm)-, cyan (C; range: 466-532 nm), green (G; range: 494-564 nm), and ultraviolet-A (UV-A; range: 383-426 nm) LED lighting. The changes in the shoot dry mass, shoot fresh mass, chlorophyll content, and nitrate content of leaf lettuce are analyzed. In the experiment, a photosynthetic photon flux of 300 ±12 standard deviation (SD) µmol·m-2·s-1 is provided for 18 h·d-1 at seedling stage and vegetative stage with such four LED sets as Lr-Lb (61.5%-38.5%), R-C-B (42.8%-30%-27.1%), Lr-Lb-G (49%-36.1%-14.9%), and R-B-UV-A (52.9%-35%-10.1%). The irradiation of different LED sets is conducted on leaf lettuce at seedling stage and vegetative stage, respectively. The air temperature, relative humidity, and CO2 levels for all treatments were maintained at 22±2°C , 64±8% , and 570±75 ppm , respectively. In term of total shoot dry mass and shoot fresh mass, the adoption of LrLbG or LrLb with other combinations results in the worst quality of plant. Provision of UV-A and cyan irradiation during the vegetative stage can increase the shoot fresh mass and dry mass of leaf lettuce.