Why Are LED Grow Lights Purple: The Secret Behind Plant Growth
Introduction
Specifically the LED grow lights particularly the purple light emitting type of LED grow lights are progressively becoming popular among home-gardening enthusiasts and commercial horticulturists. The purple hue that comes from red and blue wavelengths is necessary for the plant and it will shed this light at a particular period in the day. But why this particular color, and what ‘gain does it provide? In this article we will cover what actually happens with purple led grow lights or how they work, few real life examples and some of the actual data on how these lights enhance plant growth. Whether you are a farmer choosing between LED grow lights for lettuce or marijuana, knowing how powerful the purple LED light is will go a long way in growing the success of any indoor garden.
How Purple LED Grow Lights Support Optimal Plant Growth
Purple LED grow lights consist of combining two important spectral regions which are red and blue rays that play an important role in the photosynthesis process. These wavelengths focus on the appropriate lifecycle stages or Plant Growth and Development from seedeginning to flowering process.
The Science Behind Red and Blue Light in Purple LED Grow Lights
Red light which falls at a wavelength of between 600-700 nanometers help in the promotion of flowering and fruiting. Tomatoes and cannabis, for instance, have a positive reaction towards red light particularly during the flowering stage in that they produce even better yields as well as faster ripening. A study done on plants at the University of Guelph revealed that plants that were put under red light source though were used together with blue or white light registered up to a 20 percent increase in their production of fruits. This makes red light particularly desirable for the growers who have their focal interest on flowering plants.
Red light measuring 600-700 nm is important during the generative phase of plant growth while blue light that measures between 400-500nm helps in formation of leaf and roots. A study by Michigan State University highlighted that, blue light enhances density of stomata facility enable the plant to enhance utilization of CO2 for the process of photosynthesis. This results to bigger and thicker plants with sturdier leaves – perfect for those that grow on the surface of the soil like lettuce or spinach.
When combined together, red and blue waves are the most effective in stimulating the photosynthesis and plant growth at all the developmental phases. This is why the purple LED grow lights have been known to be appropriate for both the vegetative growth period and the flowering of the plant because it gives an optimum light spectrum required by the plant.
Case Study:
Scientific studies conducted at the Controlled Environment Agriculture Center funded by NASA have found that when leafy plant such as lettuce and basil was grown under purple led lamps the biomass yield was a quarter higher than that of plants grown under Fluorescent lamps. This was so as the red and blue wavelengths used had a way of stimulating the photosynthesis well without an extra energy consumption on the green or yellow.
How Purple Light Mimics Natural Sunlight for Plants
Although natural light is considered to contain all colors of the spectrum, the plants require mainly red and blue lights for photosynthesis. The required range of wavelengths is duplicated with purple LED lights, which provide only the areas of the light spectrum these plants require. This translates to conserving of energy as the plants do not use light in the wrong spectrum as it is not effective in their growth.
Another research conducted at the University of Arizona to compare the effect of using LED lights with that of the traditional methods showed that plants grown under purple LED light consumed 40% less energy than the plants grown under full-spectrum lighting even producing higher yields at times. This makes purple LEDs a more economical way of managing the indoor garden and commercial growers both in the vertical farming and greenhouse industries.
Maximizing Photosynthesis Efficiency with Green Light in Dense and Large Leaf Plants
Although in the concept of photosynthesis, red and blue light is significant, green light also has a critical and unnoticed function especially in plants with thicker foliage. Green light can go farther into the plant’s tissues than red and blue light could, making the latter penetrate into the deeper parts of the leaves.
Green Light Penetration for Enhanced Photosynthesis: How It Works
Red light in the wave length range of 600 – 700 nm and blue light in wave length range of 400 –700 nm are absorbed most by chlorophyll but green light in the central wave length range of 500 – 600 nm is absorbed relatively less by the chlorohpyll. But it goes further into the plant foliage, to the bottom leaves that would otherwise remain in the shade. Thus, enhanced light penetration facilitates photosynthesis even in the lowest leaves of the plant, so even the tried and overshadowed leaves of the plant give their share to its growth.
How Green Light Boosts Photosynthesis in Dense Leaf Canopies
During a thick-leaved plant like tomatoes or cannabis plant, absorption of the green light increases by a very large percentage hence promoting the production of new leaves. Some investigations have proven that the efficiency of photosynthesis gets a boost of up to 15% when green light is used especially in plants with hardy foliage. It is more so for the commercial growers planning to optimize yields from plants with a multilayer canopy.
Case Study:
Conducted by Purdue University experiment also proves that cannabis plants which have been grown under alternating purple LED light with an added green light led to enhanced overall yield that is by 18%. This shows how it is possible to harness use green light in the lighting spectrum to enhance photosynthesis in plants which have thick canopies.
UV Light and Its Impact on Plant Growth and Health: The Role of UV-A and UV-B
UV light, which is not visible to the eye of a man, equally has a great impact in enhancing the growth of plants and the yield rates. Thus, while UV-A (315-400 nm) and UV-B (280-315 nm) expose specific stress induced stress responses in plants resulting in the strengthening of the plant.
UV Light in Horticulture: Improving Plant Metabolism and Disease Resistance
UV light acts as a signal to the plants to produce secondary metabolisms for example flavonoids and terpenes leading to enhanced qualities like taste, aroma and nutritional values. UV-B is also understood to have effects of increasing the THC content of the plant by up to 30%; thus, it is an important wavelength of light for a grower who wants to maximize the strength of his/her crop.
Also, it is a fact that exposure to UV light helps to develop the compounds which increase resistance to diseases in plants. This makes UV light a perfect candidate growers who want to enhance the plant health without the use of chemicals.
How UV Light Increases Yield and Plant Health in Greenhouse and Outdoor Cultivation
Smart use of UV light as part of the lighting in greenhouse has been proven to increase yields up to 20% depending on the type of crop grown, including cannabis, tomatoes and strawberries among others. UV light is very useful in CEA as it can reproduce the natural sunlight conditions thus increasing its usefulness in the controlled environment.
Case Study:
According to a Horticulture Research article dated 2021, strawberries that are raised under UV-B light have fruits with higher antioxidants and increased shelf life as compared with plants that have limited exposure to UV light. Increase in fruit yield was also demonstrated in the same study by about fifteen percent, further proving the part played by UV light in the improvement of overall crop quality as well as productivity.
Full Spectrum vs Purple LED Grow Lights: Which Is Better for Maximizing Photosynthesis?
The next concern that growers are bound to make is whether to choose the purple LED grow lights or the full-spectrum lights. Both medium types have advantages and disadvantages depending on plants demand and environmental conditions of growth.
Comparing Light Spectrums: Benefits and Drawbacks
Purple LED grow lights as they target the most efficient spectrum that is required by plants thus minimizing wastage of energy. But, grow lights, which incorporate waves of light such as green and yellow are the closest imitation of natural light. This may be useful with plants that need a more extensive range of the light spectrum, like herbs or orchards.
Full-spectrum LEDs are also more adjustable by spectrum allowing for a great choice for growers with a variety of crops. Still, they are normally costly and require more power in comparison with the power consumed by purple LEDs.
Which Spectrum Works Best for Your Indoor Garden?
Many home gardeners and small scale growers can opt for purple LED grow lights to adequately light up their plants for proper growth throughout its life cycle. They are inexpensive, use less energy, and are easy to operate – perfect for cultivating leafy plants, marijuana or assortment of flowers. Full spectrum lights on the other hand are more appropriate for different kinds of crops or growers who want to replicate sunlight in as much way as possible.
Case Study:
Virtually a similar study conducted by the University of California revealed that plants grown in purple LEDs consumed 30% less energy while common yields were noted as those grown in full spectrum light sources. This makes the use of purple LEDs the most reasonable for energy and time conscious growers with the aim of optimizing on the effectiveness of plant growth without having to use energy for the detriment of plant health.
How to Choose Between Purple and Full Spectrum Grow Lights for Your Plants
The difference between the purple and full-spectrum LED grow lights comes to preference and the particular plants that you are growing or the type of environment that exists.
Optimizing Purple and Full Spectrum LED Grow Lights: Best Practices
However, when using purple LEDs the intensity of the light and the distance between the light source and the plants should be altered depending on the growth development phase of the plant. There should be more of blue light during the vegetation stage whereas there should be more of red light during the flower production stage. Full-spectrum lights are also flexible detailing to numerous kind of plants however slight manipulation may be needed depending on the plant type.
Full Spectrum LED Lights: Why They’re Ideal for Specialized Crops
The full-spectrum LEDs serve well cycles such as herbs, strawberries or the medicinal plants which may need steady and constant exposure to light throughout their growing and development process. Getting a broader band of light means that all the wavelengths required to let the plants grow can be given to them, resulting in better yields and quality produce.
Combining Green, UV, and Full Spectrum Lights for Maximum Growth Efficiency
Green, UV and full spectrum lights help the growers to get the best out of the lights that they install in the growing areas. Green LED increases light penetration to the canopy, UV LED increases the health of the plant and secondary product formation, and the whole spectrum of LED optimizes light for specific crops.
Case Study:
In the same trial, the plants were raised with purple, green and UV light, and it was found that the yield of cannabis in this case was 30% higher in terms of THC and 22% higher yield as compare to the plants grown in purple LED only. It shows that it is possible to have optimal yields with quality plants where more than one of these spectra are used.
Conclusion
Purple LED grow lamp is one of the most efficient sources of energy for all growth phases of the plants. They optimize on the red and blue wavelengths so as to enhance photosynthesis but at the same time use less energy. No matter whether the specimens in question are ‘regular’ greens or marijuana growing indoors, using purple LED lights is more than justified. For more advanced growers, adopting both green and UV light or changing to full Spectrum LEDs add to improving on plant health and yield.
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