You trying to start arguments? Lol.
UVB like everything else is about dosage, too much is bad, too little is ineffective.
UVB needs to be applied in afternoon with a 5000k environment, the extra blues help with with DNA excision repair. 100%
UVB @ 285nm -295nm is responsible for vitamin D synthesis in plants just like it is for humans.
Alot of the developmental changes that occur from UVB light are made to help the plant cope in more extreme environmental conditions. Truth be told there is not much of any "science" on the matter, but therein lies the catch, the very nature of UV is infinity, linked to the dodecahedron the only platonic solid with infinite numerical pathways. Basically you can never illicit the same exact precise results, similar to how no two snowflakes are the same.
Science doesn't accept results that cannot be replicated under identical conditions.
The spectral composition of light plays a crucial role in determining the phytohormone balance within a plant. Different wavelengths of light, or spectral components, trigger specific photoreceptors in plants, which in turn influence the production, distribution, and signaling of various phytohormones. This hormonal regulation then affects a wide range of developmental processes, including seed germination, morphogenesis, cell division, and elongation.
Plant Growth Regulators (PGRs) are phytohormone, which are naturally occurring plant hormones.
UVR8 (UV RESISTANCE LOCUS 8) is a plant photoreceptor that plays a crucial role in sensing and responding to ultraviolet-B (UV-B) radiation. It acts as a UV-B sensor, triggering photomorphogenic responses in plants, which are light-dependent changes in plant growth and development. When UV-B light is absorbed by UVR8, its homodimer structure dissociates into monomers, initiating a signaling cascade that ultimately regulates gene expression. This process is essential for plant survival and acclimation to UV-B stress.
Most of what it does to my knowledge is Jack's up the plant's ability to deal with extremes conditions. If you were to plan pushing the plant to limits I'd give her a full grow of uvb, light needs to be absorbing in order for the plant to develop accordingly. If you are just using it for trichomes then just stick to flower.
A little in veg is perfect, just keep it to afternoon.
UVB radiation can impact the xanthophyll cycle in plants. Specifically, it can influence the levels of xanthophyll pigments like violaxanthin, antheraxanthin, and zeaxanthin, which are crucial for photoprotection. Increased UVB exposure can lead to changes in the ratios of these pigments, potentially enhancing the plant's ability to dissipate excess light energy.
This is why I'm interested.
Hope that helps a little.
UV-A radiation
@sunset and sunrise,just like nature. UV-A radiation increases violaxanthin formation.
Under high-light conditions, violaxanthin is converted to zeaxanthin (via antheraxanthin), a process called de-epoxidation. This conversion is mediated by the enzyme violaxanthin de-epoxidase. In low light, zeaxanthin is converted back to violaxanthin by zeaxanthin epoxidase.