Impacts of breeding and cultivation practices on cannabinoids in industrial hemp

Industrial hemp (Cannabis sativa L. with < 0.3% THC) has become accessible to growers, producers, consumers, and researchers in the U.S. after decades of legal prohibition. Interest in hemp as a potential multi-purpose crop has soared creating the need for research on all aspects of production. Thus, a project was initiated to address knowledge gaps pertaining to potential impacts of LED light quality and duration on cannabinoid concentration and composition. Relatively little information exists regarding the effects of narrow spectrum lighting regimes on cannabinoids, especially blue (400-500 nm) and red (600-700). One objective of this study, described in Chapter 1, was to investigate four different light treatments – continuous red, continuous blue, red with a 2 hour dark period, and blue with a 2 hour dark period – on cannabinoids in one high-CBD variety called Early Abacus. Flowers were collected at two maturation time points and analyzed by UPLC. A second objective was to compare UPLC to near-infrared spectroscopy (NIR) for measuring cannabinoid concentration. Results showed that cannabinoid production was lowest under continuous red LED light compared to other treatments. Findings further suggested that a brief dark period had no significant impacts on cannabinoid levels, which may help growers maintain production while managing energy costs. Furthermore, NIR compared well to UPLC, but with certain caveats related to method of tissue preparation. Once optimized, NIR could allow more efficient screening of plants in the field or greenhouse without time-consuming extraction and analysis steps in the laboratory. A second part of this thesis described in Chapter 2 reports findings for cannabinoids in plants from field trials conducted in 2021 as part of a hemp breeding program and evaluations of variety performance for Midwest growing conditions. Cannabinoid data are provided for feral hemp populations collected in Illinois, commercial hemp varieties, and first-generation hybrids. This study represents the first field trial and chemical analysis involving Illinois feral hemp in over 50 years. New chemical data are provided for Illinois feral hemp and commercial varieties grown for the first time in the Midwest. Most feral plants were found to dominate in CBDA/CBD compared to THCA/THC, but populations varied widely in total cannabinoid levels. This finding is not surprising since feral hemp are thought to be descended from fiber varieties grown in the Midwest during WWII. Chemical data are also provided for commercial fiber and CBD varieties grown for the first time in the Midwest. Some cultivars were identified that might be unsuitable for development due to total THC levels approaching or exceeding the legal threshold of 0.3%.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Crop Sciences

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2023

Author dc:creator

• Vargas, Krystal A

Contributors dc:contributor

• Riggins , Chance W
• Juvik, John J
• Lee, DoKyoung

• Hemp
• Cannabinoid(s)
• Led

Statement dc:rights

• Copyright 2023 Krystal Vargas

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/120589

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F120589