Far red light (700–850 nm) is nearly invisible to the human eye, and commonly confused with infrared light. Although far red light can generate heat, it does so far less efficiently than infrared.
Since far red light has a wavelength range that is longer than most plants can absorb, 700 nm, horticulturists have long believed that plants don’t benefit from it. Cependant, current research indicates that plants do react to wavelengths as high as 780 nm. En plus, far red light has the ability to affect plant growth when used in conjunction with lumière à spectre complet.
Boosts Photosynthetic Effectiveness
Zhen and Bugbee (2020) found that increasing the amount of far red light in a spectrum of shorter wavelengths increased canopy photosynthesis to the same extent as increasing the amount of light in the PAR range (400–700 nm) at the same intensity. They came to the conclusion that photosynthesis is enhanced by interactions between far red photons and photons with shorter wavelengths.
Aids in Plant Growth
Although far red light is hardly seen with the naked eye, it has a significant impact on plant extension growth. This means that far red light can affect the size of a plant’les feuilles, tiges, and ultimately its height and total size.
Most plants respond by avoiding shade when the far red photons increase. When plants are exposed to far red light, they naturally respond by seeking out more light since they believe they are in the shade. Plants will consequently grow taller or have larger leaves in order to absorb more light.
PLUS: Comment différents spectres affectent-ils la croissance des plantes?
