Each spectrum represents an electromagnetic frequency measured in nanometers one billionth of a meter : Do plants use all light spectrums produced by the sun? Most indoor growers seem to believe that the best indoor grow lights would have the same light spectrum as the sun — a relatively full spectrum over the visible light frequencies.
After all, plants evolved over millions of years to best convert light energy into carbohydrates and sugars. The most readily available light from the sun is in the middle spectrums which we see as green, yellow and orange. These are the primary frequencies that human eyes use. However, studies show that these are the least used light frequencies in plants.
Most of the photosynthetic activity is in the blue and red frequencies, which makes full spectrum LED grow lights so beneficial.
The main reason for this counter-intuitive use of light by plants seems to be related to early forms of bacteria and the evolution of photosynthesis. Photosynthesis first evolved in bacteria over millions of years in the primordial sea. This evolved in bacteria long before the appearance of more complex leafy plants. These early photosynthetic bacteria extensively used the yellow, green and orange middle spectrums for photosynthesis which tended to filter out these light spectrums for plants evolving at lower levels in the ocean.
As more complex plants evolved at lower levels, they we left with only the non-filtered spectrums not used by bacteria — mostly in the red and green frequencies. The yellow, green and orange light is mostly reflected off the surface of the leaves and this is why photosynthesizing plants are green. Do different light spectrums do different work in plants? How plants respond to light is important in understanding photosynthesis; for example, different light spectrums are used for different types of growth in plants.
There are millions of photosynthetic receptors in a leaf of a green plant. Each receptor includes specialized pigments that absorb specific light frequencies during photosynthesis. By measuring the amount of oxygen produced under various light spectrums we can measure the amount of photosynthetic activity under each light spectrum.
This has produced a very detailed map color frequency chart of which light spectrum is related to which type of plant growth, which helps find the ideal photosynthesis wavelength for each specific crop. How do plants use different light spectrums? Ultraviolet light 10nmnm Though overexposure to radiation in the UV light spectrum is dangerous for the flora, small amounts of near-UV light can have beneficial effects. In many cases, UV light is a very important contributor for plant colors, tastes and aromas.
Studies show that nm UV light promotes the accumulation of phenolic compounds, enhances antioxidant activity of plant extracts, but does not have any significant effect on growth processes. Blue light nmnm This range of spectrum enables cryptochromes and phototropins to mediate plant responses such as phototropic curvature, inhibition of elongation growth, chloroplast movement, stomatal opening and seedling growth regulation.
Some wavelengths of interest for growers using LEDs, within the nm range, applicable to plants growth, are: nm is the blue absorption peak of chlorophyll a. Carotenoids are starch-storing, structural and nutritional compounds.
Phycoerythrin is a red protein-pigment complex from the light-harvesting phycobiliprotein family, present in red algae and cryptophytes, and is an accessory pigment to the main chlorophyll pigments responsible for photosynthesis.
Phycocyanin is a pigment-protein complex from the light-harvesting phycobiliprotein family, along with allophycocyanin and phycoerythrin. It is also an accessory pigment to chlorophyll.
It is needed for all kinds of morphogenic shape-forming processes. A few minutes of nm light treatment after the full light cycle is over will revert the phytochrome chromophore from activated to inactive. This resets the chemistry for another lights-on cycle and may be useful in shortening the classic dark side of the photoperiod.
LEDs provide growers the unique opportunity to use a light spectrum that can be tailored to provide maximum benefit to the plants and minimize wasted energy. Several LEDs at different wavelengths can be combined to provide an ideal illumination source that follows the plant-sensitivity curve. The reason a phosphor coating is helpful in full spectrum grow lights is that phosphors take light from a single narrow wavelength range e.
Because phosphors emit light of so many different wavelengths, the result is a balanced mixture of colors that result in white light. Just because an LED grow light emits white light, that does not necessarily mean that it is truly a full spectrum light source. One convenient method is to evaluate its color rendering index CRI.
This is a useful metric because it tells us how similar it is to natural daylight. A higher CRI rating indicates that the light source is more similar to natural daylight, which is an ideal, full-spectrum light source. The primary red peak absorption occurs at nm, but absorption occurs at across a relatively wide range between and nm.
From these chlorophyll spectra, it is clear that both blue and red light work well for allowing plant photosynthesis to occur. In particular, peak wavelengths at nm, nm, nm and nm are essential for efficient growth. It is important to provide plants with a balanced "diet" of different wavelengths, however. Just like a human bodybuilder, in addition to needing to consume sufficient amounts of protein, a balanced diet of vitamins and various food groups is necessary for health.
Similarly, plants can be encouraged to grow quickly with both blue and red light; however, it is critical that they also receive light across the spectrum. We know that natural daylight is extremely effective for healthy plant growth, so we take a look at natural daylight spectra, as shown below. Summer Daylight Natural daylight has a continuous and extremely wide coverage across the spectrum. In particular, summer daylight is characterized by relatively equal amounts of energy at all wavelengths.
Fall Daylight As the seasons change from summer to fall, the spectrum of light that reaches the ground also changes due to the lower angle of the sun.
Conclusion So, in conclusion, it cannot be stressed enough that these recommendations are only starting points for using LED lamps for growing plants.
After all, plants evolved over millions of years to best convert light energy into carbohydrates and sugars.
Using Spectrum Control with Cannabis The exact way that plants use light is very specific to individual plant species and their natural environment. This is a key shift for plants who depend on this to signal changes in their growth to reproductive strategies such as flowering and fruit production. But it is the best and most common system we have right now for evaluating grow lights. Making a lot of white light to impress us is a waste of energy.
This transition is not clearly defined, and some strains have big increases in resin production during this period, and others not as much. Maximum flower matter size and good structure is generally the goal here. Sodium by itself produces a mostly yellow spectrum range, which is why HPS are extremely heavy in this range of wasted light.
Phycoerythrin is a red protein-pigment complex from the light-harvesting phycobiliprotein family, present in red algae and cryptophytes, and is an accessory pigment to the main chlorophyll pigments responsible for photosynthesis. Spectral quality: Spectral quality of a carefully chosen LED illumination source can have dramatic effects on plant anatomy, morphology and pathogen development. Do different light spectrums do different work in plants? Conversely, blue light does not increase cell size. Most of the photosynthetic activity is in the blue and red frequencies, which makes full spectrum LED grow lights so beneficial.
Each spectrum represents an electromagnetic frequency measured in nanometers one billionth of a meter : Do plants use all light spectrums produced by the sun? This image shows the spectra of three bulbs; blue, yellow and red. One convenient method is to evaluate its color rendering index CRI. Plants, incredibly, through light know what season it is, what time of day it is, whether there are other plants around them, and whether it is time to make babies flowers and seeds, that is.