gallium–aluminum–arsenide light-emitting diode (LED) lighting
systems have several unique advantages, including the ability
to control the spectral composition, a small mass and volume,
durability, long operating lifetimes, wavelength specificity and
narrow bandwidth, relatively cool emitting surfaces, minimum
heating, and photon output that is linear with the electrical input
current. These solid-state light sources are therefore ideal for
use in plant lighting designs, and they allow wavelengths to be
matched to plant photoreceptors to provide more-optimal production,
and influence plant morphology and metabolism (Bourget,
2008; Massa et al., 2008; Morrow, 2008). Spectral light changes
evoke different morphogenetic and photosynthetic responses that
can vary among different plant species. Such photoresponses are
of practical importance in recent plant cultivation technologies,
since the feasibility of tailoring illumination spectra purposefully
enables one to control plant growth, development, and nutritional
quality.