Influence of different UV spectra and intensities on yield and quality of cannabis inflorescences

Daniel Stefan Huebner; Marat Batarshin; Sebastian Beck; Leon König; Inga Mewis; Christian Ulrichs

doi:10.3389/fpls.2024.1480876

Influence of different UV spectra and intensities on yield and quality of cannabis inflorescences

Front Plant Sci. 2024 Dec 17:15:1480876. doi: 10.3389/fpls.2024.1480876. eCollection 2024.

Authors

Daniel Stefan Huebner¹, Marat Batarshin¹, Sebastian Beck², Leon König¹, Inga Mewis¹, Christian Ulrichs¹

Affiliations

¹ Division Urban Plant Ecophysiology, Faculty of Life Sciences, Humboldt-Universität zu Berlin, Berlin, Germany.
² Department of Chemistry, Humboldt-Universität zu Berlin, Berlin, Germany.

Abstract

The raising economic importance of cannabis arouses interest in positively influencing the secondary plant constituents through external stimuli. One potential possibility to enhance the secondary metabolite profile is the use of UV light. In this study, the influence of spectral UV quality at different intensity levels on photomorphogenesis, growth, inflorescence yield, and secondary metabolite composition was investigated. Three UV spectra with five different intensities were considered: L1 (UVA:B = 67:33, 4.2 W/m²), L2 (UVA:B = 94:6, 4.99 W/m²), L3_1 (UVA:B = 99:1, 1.81 W/m²), L3_2 (UVA:B = 99:1, 4.12 W/m²) and L3_3 (UVA:B = 99:1, 8.36 W/m²). None of the investigated UV treatments altered the cannabinoid profile. Regarding the terpenes investigated, light variant L3_1 was able to positively influence the terpene profile. Especially linalool (+29%), limonene (+25%) and myrcene (+22%) showed an increase, compared to the control group without UV treatment. Growth and leaf morphology also showed significant changes compared to the control. While a high UVA share increased the leaf area, a higher UVB share led to a smaller leaf area. Of the UV sources examined, only L3_1 with 1.81 W/m² and a radiation dose of 117.3 kJ m² d^-1 is suitable for practical use in commercial cannabis cultivation. The terpene concentration for this group was in part significantly increased with constant yield and cannabinoid concentration.

Keywords: UV radiation; cannabinoids; cannabis; quality; secondary plant metabolites; terpen; yield.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This research was funded by the German Ministry for Education and Research (BMBF) in the frame of the CUBES project, grant number 031B0733A. The article processing charge is funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation)—491192747 and the Open Access Publication Fund of Humboldt-Universität zu Berlin.