Since plants have evolved over millions of years to grow in sunlight (which consists of the whole spectrum of visible light plus ultraviolet and other non-visible wavelengths), my first instinct as to which is better for plant growth, as I am sure yours will be, is to vouch for sunlight. What could be better than beautifully natural sunlight stimulating our plants to grow? But before we dismiss the idea of human-made Image of the sun against a blue sky lighting, we should acknowledge that there is some evidence where one might argue that nature is not as optimally designed as it might first appear. There have been studies that have suggested that too much light (and in particular the yellow color wavelengths) can start to stress plants out and inhibit their growth by suppressing chlorophyll formation. Since we are pretty sure that plants don’t use every wavelength of light within sunlight and some wavelengths may even be inhibitory, this raises the question of what happens if we were to remove those undesired wavelengths. Is it possible to increase the level of growth in our plants?
Another argument in favor of us having the potential to design lighting that is ‘better’ than sunlight is that nature evolved not to please us humans, but through a Darwinian ‘fight for survival’ mechanism from the point of view of the plant. So ‘better’ growth might mean different things from a plant’s perspective than it does from morphman 2-rig 6 small ours and there might be some naturally-evolved plant processes that may be undesirable to us as plant growers. An example of this can be seen with fruit-growing, where we have become quite adept at crossing plants to produce ‘better’ varieties of fruit which do not contain seeds (for instance, seedless grapes or some types of citrus fruit). Yet the whole reason for a plant to produce fruit in the first place is as a mechanism for it to disperse its seeds – what possible use is there for a plant to have seedless fruit? – there isn’t.
Of course there are also other more practical reasons why we might not be able to grow our plants in sunlight, like we may not have the space to grow them outside in the first place or we may not want to expose them to the possibility of pests and diseases. Alternatively, we may live in a place that is often overcast (sound familiar?) or where the outside conditions are unsuitable for the type of plants that we would like to rear.
Irrespective of our reasoning for growing plants under electric lighting, the problem we currently face is that scientists are a long way from fully understanding all the complicated systems and processes that go on in a plant in response to sunlight, and for that reason, given the choice between trusting a couple of hundred years of scientific endeavour versus millions of years of evolution, it’s really a no-brainer. So when choosing indoor lighting, we should try to stay as faithful as possible to the structure of sunlight, and we can use our current knowledge of what photosensitive pigments are found in plants as a guide to determining the wavelengths of light that are required for optimal plant growth, even if we don’t yet fully understand what all their functions are.
We choose LED grow light as the light source for plant growth, we can customize the light ratio for different plants. And for a plant, we also can adjust the spectrum for different growth stages of plants.
LED grow lights can produce much more light per watt than fluorescent or HID lighting. This also means that they run cooler, reducing electricity costs as well as the risk of fire in your grow room. Most LED grow lights come with small fans built in, and do not require additional ventilation except in special circumstances. Another bonus is that they do not require ballasts. Overall, they return much higher yields for lower levels of electricity consumed.