Development of Cannabinoids in Flowers of Industrial Hemp ( Cannabis sativa L.): A Pilot Study

• Published in: Journal of agricultural and food chemistry Vol. 68; no. 22; pp. 6058 - 6064
• Main Authors: Yang, Rui, Berthold, Erin C, McCurdy, Christopher R, da Silva Benevenute, Sarah, Brym, Zachary T, Freeman, Joshua H
• Format: Journal Article
• Language: English
• Published: United States 03.06.2020
• Subjects: Cannabinoids - analysis; Cannabinoids - metabolism; Cannabis - chemistry; Cannabis - growth & development; Cannabis - metabolism; Chromatography, High Pressure Liquid; Flowers - chemistry; Flowers - growth & development; Flowers - metabolism; Pilot Projects; Plant Extracts - analysis; Plant Extracts - metabolism; cannabis sativa; CBG; CBD; CBD/THC ratio; THC
• DOI: 10.1021/acs.jafc.0c01211
• ISSN: 0021-8561

A field study was performed to investigate the development of cannabinoids in flowers of industrial hemp using three day-length-sensitive and two day-length-neutral varieties. Flower samples were analyzed for cannabinoids on a weekly basis from 2 to 4 weeks postanthesis to plant senescence. Results indicate that total THC, CBD, and CBG significantly increased as flowers matured, reaching the greatest concentration during 6 to 7 weeks postanthesis. After a plateau stage of varied length for different varieties, the peak concentrations declined as plants senesced. Total THC was above the 0.3% threshold from 4 weeks postanthesis to the end of the growing season for day-length-sensitive varieties, but this only occurred during 6 to 7 weeks postanthesis for day-length-neutral varieties. The CBD/THC ratio in flowers dynamically changed during the entire reproductive stage for all of the evaluated varieties. The current study provides vital information for successful cultivation of industrial hemp.