Although the effects of UV cultivation have been studied for many years, there are still many misconceptions about UV, including the belief that all UV is bad for plants, or that only UVB is valuable. Next, we will share with you some research results on the benefits of UV-A for planting.
First let's take a look at what is UV?
The general term for light in the wavelength range of 10nm-400nm, which is subdivided into UVA/UVB/UVC. They correspond to different wavelength ranges respectively. UVA: 320nm-400nm / UVB: 275nm-320nm / UVC: 200nm-280nm. The shorter the wavelength, the stronger the damage ability to living things, but the weaker the transmission ability.
Due to the presence of the atmosphere, almost no UVC reaches the Earth's surface. At sea level near the equator, 6% of solar radiation is ultraviolet, of which UVA is 5.7% and UVB is 0.3%. Depending on latitude, altitude and time of year, plants receive 10 to 100 times more UV-A than UV-B. Therefore, it can be said that light containing UVA is in line with the natural living environment of plants.
Reasons to use UVA for indoor cultivation:
1. UV-A increases production
Often misleading UV studies are not done on whole leaves or whole plants, but just some algae or chloroplasts. In fact, plants themselves have good natural adaptability to UVA, and different species show similar responses but different response mechanisms. The following series of studies have collectively demonstrated the above opinion.
2. Increase the nutritional value of harvest
We all know that human exposure to moderate amounts of UV rays has benefits, such as boosting the body's synthesis of vitamin D. A similar reaction occurs in plants. Plants respond to low-dose UV light by producing antioxidant compounds such as flavonoids and phenolic compounds, which often give fruits and vegetables their bright blue or purple hues. And many of these compounds are antioxidants, which are beneficial to the human body. Flavonoids are strongly associated with longevity, weight management, heart health and reduced cancer incidence and avoidance of neurodegenerative diseases. Other phenolic compounds are also of great interest for the prevention and treatment of cancer.
3. UVA changes the growth state of plants and allow it to have better growth.
Plants will judge their position according to the change of light quality, so as to adopt different growth postures. A typical example is the shading effect. When the spectrum loses ultraviolet, blue and red light and contains a high proportion of green and infrared light, the plant will think that it is shaded, then it will grow leggy and cannot bring a good harvest. The opposite plant will think that it is bathed in sunlight, resulting in better growth. Below are some of the findings.
4. UVA can effectively control plant diseases.
UVA light will increase the thickness of the leaf surface, thereby increasing the resistance to fungal infection. At the same time, there is a near-UVA light with a wavelength of 405nm that has been proved to be harmless to organisms such as humans or plants, but it can kill bacterial diseases. . For details, please refer to our previous article introduction (https://www.ultraplantled.com/news/why-your-cannabis-grow-light-needs-uv-77491.html)
All in all, an effective grow light should contain UVA. Most 3500K/6000K Grow Lights on the market do not have light in this band at all. Ultra Plant™, a brand of grow lights of Feton, is serving the plants and growers with the most comprehensive spectrum. More product information could visit:https://www.ultraplantled.com/150w-led-grow-light/
