UVB plant fill light is primarily used to mimic the ultraviolet B (UV-B) band of natural sunlight, a type of light that in a natural environment can help plants carry out a number of specific physiological responses.
However, in most cases, the primary photosynthesis in plants is driven by red light (~660 nm) and blue light (~460 nm). Therefore, supplemental lights typically used for plant growth will focus more on these wavelengths of light. Nonetheless, UV-B light can be useful for some plants, for example, it can:
1. promote flowering and fruiting in some plants;
2. increase disease resistance in some plants;
3. affect the production of plant pigments, resulting in more vibrantly colored fruits or leaves; and
4. promote the production of secondary metabolites, such as vitamin C, for some specific plants.
It should be noted, however, that not all plants need UV-B light, and that too much UV-B light may cause damage to plants.
Therefore, you need to be careful when using UVB plant filler lights and should adjust how and when you use them depending on the specific plant species and its stage of growth. If you intend to use UVB plant filler lamps to assist in plant growth, make sure you understand your plant species and their light needs. It is also important to take appropriate precautions when using UV-B light, considering that it can be potentially harmful to human skin and eyes.