There has been heated debate amongst experts over the importance of UV light for plants. Some agriculturists even wonder whether ultraviolet light has any place in plant cultivation of any kind at all. If you are growing plants indoors, you must supplement your plants with it.
Here, we discuss everything you need to be aware of this UV light wavelength and the best ways to add it to your indoor farm.
What is UV Light?
UV light or ultraviolet light is electromagnetic radiation extracted from natural sunlight. You get exposed to UV light whenever you are outdoors in the sun. It is categorized into three wavelengths: UVA, UVB, and UVC.
It assists plants in growing in several ways, and it can improve the overall potency and quality of the flowers. But, only a few types of UV light are beneficial to various types of plants.
Different Types of UV Light
Both UVA and UVB are essential parts of life on earth, but UVC is not. The ozone layer filters out UVC. Consequently, it never really makes it to the outdoor plants.
In addition to these three types, there is also a fourth type of UV light. The wavelength of this light ranges between 10 and 180 nm. This variety is called extreme or “vacuum” UV since it propagates only in a vacuum.
Ultraviolet A (UVA)
Ultraviolet A or UVA light ranges between 320 nm and 400 nm. Additionally, it contains roughly 3% of the photons found in natural sunlight when it breaks through the earth’s atmosphere. Additionally, it does not have any harmful effects on DNA.
Ultraviolet B (UVB)
UVB or ultraviolet B has wavelengths ranging between 29 nm and 320 nm. It contains roughly a fifth of 1% of overall natural sunlight. However, in contrast to UVA, it can damage DNA. Moreover, it has been known to cause cancerous effects on animals and humans.
However, the composition is too small; the ozone layer can better block it. It rarely reaches the earth in significant amounts to do any lasting damage.
How Does UV Light Benefit Plants?
Plants have different responses to UV light. The reactions are dependent on the wavelength, type, and species of the plant. The most important benefits of adding UV spectrum to your grow room include higher flower quality, potency, and weight. Studies have proved that both UVA and UVB light can assist the production of flavonoids and terpenes in plants.
The flavor and aroma of the fruits are better
Some farmers have cultivated tomatoes in a greenhouse using grow lights without UV. They noticed the tomatoes grew great; however, the taste was not up to the mark. They produced another batch with supplemental UV and found that UV light amplified aroma and flavor significantly.
This is an excellent finding for those ever-increasing flowers. It means UV light will enhance the aroma and taste of your flower. Another study found that flowers without UV light will miss out on six critical terpenes. Terpenes affect the taste and aroma of the flower.
Increase in potency
Studies have proved that UV can increase oils and resins found in plants explicitly grown. This effectively means your flower will be more potent. Consequently, you can get higher prices as a commercial farmer. UV light can increase the root mass of your plants. It can increase veg branching with less stretching – leading to tighter internodes and heavier harvest weight.
Increased resistance to stress & disease
Furthermore, farmers notice an increased resistance to stress and disease when supplementing UVA and UVB spectrums.
The plants can produce up to fifteen different variant defense proteins when exposed to UV light. It has wavelengths less than 300 nm can destroy harmful microorganisms. Additionally, UV light can increase your plant’s resistance to fungus, bacteria, and insects.
Growing plants indoors without any UV exposure, you’ll lack these benefits.
UV light faster germination
UV light can promote faster germination of seeds. It provides strength to the plant. Additionally, it prepares the plant for higher light intensities. It reduces the “shock” time of the seedlings besides speeding up the germination.
When Should You Give Plants UV Light?
There are varied views about when using UV light is adequate. Some growers have the view that you shouldn’t use it during veg, as it won’t contribute much and will be a waste of money. It is recommended to use UV lighting complete cycle from seed to harvest. Today farmers can achieve these with the help of smart monitoring system.
When you expose UV light to your plants during propagation & early veg, they will develop thicker cuticles, faster metabolism, and be more robust and healthier overall. All of this adds up to a plant that can yield heavier and more potent. So, instead of adding in high doses of ultraviolet light at critical points, it is recommended to use low amounts of UV light over the entire life. This is safer and more effective. Even compared to shade plants.
Can UV Light Be Harmful To Plants?
There are plenty of benefits in using UV light while growing plants, but is there any chance that the light is harmful to plants? Assuming that you are using the proper light, you need not worry about harming your plants. Attempting to use a tanning lamp can be dangerous and may yield poor results. Ensure that you purchase a light designed specifically for growing plants.
How Much UV Light Do Plants Need?
Before you go and buy an industrial UV lamp for your plants, You need to understand that plants requirements for UV light are super low. You can get excellent results with just 2-3 watts of ultraviolet light per square foot of growing space. For a 4′ by 4′ tent, you would be just fine with around 32-48 watts of UV lighting to get the desired benefits.
Growers Need To Stay Safe While Using UV Light
Although the UV light may not be harmful to your plants, they can be for you. In few instances, artificial UV can be more damaging to your skin than the sun because you are closer to it. So, it would help if you took measures to care for your eyes by wearing protective eyewear. It is recommended that you wear sleeves when you are working around your lights.
What Is The Best UV Light For Plants?
You must provide your plants with a high-quality UV grow light for the best results. Many full spectrum LEDs will emit just the right amount of each type of UV. It will mimic natural sunlight, too, so plants will feel as though they are being grown outdoors. Even ceramic (CMH) grow lights emit ultraviolet light, and some double-ended (DE) bulbs.
UV Grow Lights For Plants And The Advantage Of Pulsed Xenon Light (PXL)
What happens when plants are grown indoors like vertical farms, nurseries, and greenhouses? Growing plants indoors requires controlled temperature, humidity, light, and gases, and natural light is generally augmented with artificial light.
Pulsed Xenon Light or PXL is as close as you can get to natural light.
Different ultraviolet C devices are LED- UVC, low-pressure mercury (LPM) lamps, and the more advanced pulsed xenon light (PXL).
PXL light has a clear advantage over other UVC devices because it mimics natural sunlight, having a broad spectrum of wavelengths- from ultraviolet to visible to infrared light. LPM and LED- UVC, on the other hand, contain either one wavelength or a narrow spectrum of light, primarily based on portions of the UVC spectrum only.
PXL promotes plant growth and enhances their nutrient content
Plants and vegetables grown using PXL technology are more nutrient-rich. One study looked at the influence of this light on mushrooms. They found that exposure to PXL light caused mushrooms to increase vitamin D production, thus boosting their nutritional value. Furthermore, a few more studies revealed that this vitamin D boost was achieved within a brief 1–2 s (3–6 pulses). How much can vitamin D provide mushrooms exposed to UV light? According to another study, one serving of UV-B pretreated sliced oyster mushroom covered the weekly demand for vitamin D.
3. PXL helps farmers save water and harvest their produce faster
Using UV light in vertical farming can be cost-effective and profitable for farmers.
By growing plants indoors, the environment is well controlled and promotes the rapid growth of plants and vegetables, also nutrient-rich.
4. PXL UV light disinfection – effectively kills plant microbes
Like humans, plants can also get infections by various bacteria, viruses, and fungi. The UVC portion of the PXL light effectively kills or inactivates a wide range of microbes. Exposure to pulsed xenon light can help farmers grow disease-free plants. Ideally, the ultraviolet light disinfection treatments should start at the beginning of a plant’s life.
This would help the plant defend itself against diseases and pest attacks while using water and nutrients from soil more efficiently- without the need for genetic modification, use of chemicals, or other unnatural treatments.