The ratio of red, green, blue, far-red, and ultraviolet light is wrong to describe the spectrum of plant lights. The spectral wavelength ratio chart is the most intuitive way of expression!

 

When customizing the spectrum of the grow light, many customers will give a ratio of red, green and blue light, or the ratio of ultraviolet light, blue light, green light, red light, and far-red light; this is very imprecise, or even wrong, I can follow Exactly the same proportions produce a completely different spectrum.

Figure 1: A phosphor-excited grow light LED spectrum

 

Figure 1 is a blue LED chip. The spectrum excited by the phosphor is the so-called full spectrum of the LED.

Calculated according to the photosynthetic light quantum flux density PPFD, the spectral ratio is:

Red light (600-700nm): 83%

Green light (500-599nm): 4%

Blue light (400-499nm): 13%

Far red light (701-780nm): 33%

Ultraviolet light (UVA I 340-399nm):0.6%

 

Note: The band ratio is divided by the total PPFD value (400-700nm). If the ratio of ultraviolet light and far-red light is calculated, the total ratio will exceed 100%.

 

 

The image below is the same spectrum with the exact same red-green-blue ratio as in Figure 1, but we can see that the spectral shape is completely different.

Figure 2: A plant light spectrum with a red-to-blue ratio, this spectrum has a much higher luminous efficiency

 

Figure 2 is a plant light spectrum with a red-blue ratio, and the red-green-blue ratio is exactly the same as the full spectrum of Figure 1.

Calculated according to the photosynthetic light quantum flux density PPFD, the spectral ratio is:

Red light (600-700nm): 83%

Green light (500-599nm): 4%

Blue light (400-499nm): 13%

Far red light (701-780nm): 32%

Ultraviolet light (UVA I 340-399nm): 0.2%

 

From the above 2 spectrograms, it can be seen that there is a very big difference, and the cultivation effect of the plant lamp will also be very different.

 

 

The figure below is a photosynthetic absorption spectrum curve of a plant.

Figure 3 Light absorption curve of a green leafy plant

 

 

The figure below is the spectrum of the new type of plant light with a peak value of 437nm

Figure 4, F22D spectrum, 437nm peak green leafy vegetable plant spectrum

Calculated according to the photosynthetic light quantum flux density PPFD, the spectral ratio is:

Red light (600-700nm): 50%

Green light (500-599nm): 18%

Blue light (400-499nm): 32%

Far red light (701-780nm): 12%

Ultraviolet light (UVA I 340-399nm): 0.1%

 

 

 

Figure 5, the same is the spectrum of the new type of plant light with a peak wavelength of 437nm. The efficiency of this spectrum will be higher. The spectrum is F22F2, the blue light peak is 437nm, and the red light peak is 663nm.

Figure 5, F22F2 spectrum, Recommended spectrum of hydroponic vegetables

 

Calculated according to the photosynthetic light quantum flux density PPFD, the spectral ratio is:

Red light (600-700nm): 50%

Green light (500-599nm): 22%

Blue light (400-499nm): 28%

Far red light (701-780nm): 13%

Ultraviolet light (UVA I 340-399nm): 0.1%

 

The higher the degree of agreement between the spectral peak of the plant lamp and the peak of the photosynthetic absorption curve of the plant, the higher the photosynthetic efficiency.

Different blue light peaks and red light peaks have very different spectral efficiencies, so the ratio of red, green and blue cannot be used to describe or express the quality of the plant light spectrum.