UV Light Benefits for Cannabis
Aside from increasing THC content, UV wavelengths have other benefits. UV-A light increases anthocyanin content while UV-B light increases the amount of lycopene, beta-carotene, glycosides, and hydroxycinnamic acid derivatives (Li & Kubota, 2009; Neugart et al., 2014; Pérez et al., 2009). These compounds can change the color, flavor, and smell of a plant. These changes in color, flavor, and smell often make plants more appealing to humans, but more toxic to some insects. Plants with increased levels of these flavor/smell compounds are less likely to get eaten by insects (Rechner, Neugart, Schreiner, Wu, & Poehling, 2017)! This means that ultraviolet lights can decrease herbivory from pests. Lastly, there is strong evidence that UV-B light prevents the spread and severity of fungal spores (Palmer, Drees, Foster, & Lindner, 2018).
Ultraviolet light is useful for more than just increasing THC content. As a grower, it’s important to weight the benefits and costs of using UV light to decide if it will significantly improve your grow environment.