The UVB light will impact the terpene profile of the plant more than its growth. Introducing the UVB light near the end of a cannabis plant's life will shift the plants focus from flower production to self defense. The harsh spectrum of light emitted by the UVB will cause the plant to produce more and more trichomes to defend itself and in the same time get as sticky as possible to catch as much as pollen possible before the end of its life.
UVB (Ultraviolet-B) radiation benefits plant growth by stimulating the production of secondary metabolites, enhancing aroma and flavor in edible plants, altering morphology for better light capture, increasing pigment production for vibrant colors, activating stress response mechanisms, and promoting photo repair mechanisms.
It's important to use UVB exposure in a controlled and moderate manner, as excessive or prolonged exposure can harm plants by causing photoinhibition, leaf damage, and reduced growth.