Plants receive light quality in different ways. One of them is through its phytochrome pigment, present in a red absorbing form (PR) and a far-red absorbing form (PFR). Both radiations and the ratio between the two affect the development of the plant. A high R:FR ratio delays flowering and reduces the length, and the presence of far-red triggers extension growth, including leaf expansion, and promotes flowering by mechanisms such as:
To optimize plant development, red and far-red radiation is essential.