Effects of red and blue spectrum of light emitting diodes (LEDs) on the growth and photosynthesis of lemon basil (Ocimum × citriodorum)
Light emitting diodes (LEDs) have tremendous potential as supplemental or sole-source lighting system for crop production. Their small size, durability, long operating lifetime, wavelength specificity, relatively cool emitting surfaces, and linear photon output with electrical input current make these solid-state light sources ideal for use in plant lighting designs. A study aiming at examining the effects of four different irradiance levels of LEDs (50, 80, 120 and 150 µmol m-2 s-1) with red and blue spectrum (4:1) on the growth and physiology of lemon basil (Ocimum × citriodorum) in a growth room was conducted. The effect of varying irradiance levels on plant height can be clearly seen on 12 days after planting and beyond. Similar trends of responses were also seen in plant canopy, leaf number and leaf area. Differences in all parameters measured were more obvious as the plant growth advanced. Fresh weight of leaves, roots and stem were markedly affected by the treatments. Within the available dry mass accumulated, its distribution into leaves, stem and roots were not affected by irradiance levels. Variation in irradiance significantly altered leaf photosynthesis with their respective values of 5.95, 5.37, 5.98 and 8.27 µmol m-2 s-1 for plants grown under 50, 80, 120 and 150 µmol m-2 s-1. Data generated from this study revealed that light emitting diode (LEDs) with irradiance level between 120-150 µmol m-2 s-1 can be effectively used as an artificial light source for commercial production of lemon basil under indoor condition.
Mat Daud, Z., Awang, Y., Ismail, F. and Mohamed, M.T.M. 2017. Effects of red and blue spectrum of light emitting diodes (LEDs) on the growth and photosynthesis of lemon basil (Ocimum × citriodorum). Acta Hort. (ISHS) 1152:183-188
light emitting diodes (LEDs), red and blue light spectrum, lemon basil, plant growth, leaf photosynthesis