The solar spectrum is a continuous spectrum, in which the blue and green spectrum is stronger than the red spectrum, and its visible spectrum range is about 380~780 nm，The intensity of sunlight is not the higher the better, for the growth of plants and animals is selective。

Blue-violet light and green light in the visible light have a great effect on the growth of plants and the formation of young shoots.  This kind of light can elongate plants and make them form short and thick forms.  At the same time, blue-violet light is also the most important light to control cell differentiation.  Blue-violet light can also affect the phototropism of plants.  Ultraviolet light is to make the formation of some growth hormones in the plant body is inhibited, thus inhibiting the elongation of the stem;  Ultraviolet light can also cause phototropism sensitivity and promote the formation of anthocyanins as well as the blue, violet and cyan light in the visible light.  Both red light in visible light and infrared light in invisible light can promote germination of seeds or spores and elongation of stems.  The red light in the plant supplement lamp can also promote the decomposition of carbon dioxide and the formation of chlorophyll.

The effect of the spectrum on the photosynthesis of the plant.  The light that affects the plant more is mainly three categories.  Ultraviolet, visible and infrared light.