Date of Award
12-1-2025
Degree Name
Master of Science
Department
Biological Sciences
First Advisor
Leme, Jose
Abstract
Cannabis (Cannabis sativa L.) is an emerging high-value crop that belongs to the Cannabaceae family and the genus Cannabis, which is known to produce more than 200 cannabinoids. Although genetic variation is the main factor in cannabinoid production, water-deficit stress is believed to induce its production. The objective of this master’s thesis was to determine the effects of water-deficit stress frequencies and timing on growth, physiology, yield, and cannabinoid concentration in cannabis. Heidi cultivars were planted in a controlled environmental growth unit. One period of water-deficit stress was found to produce the lowest concentration of total CBD and THC. In contrast, three periods of water-deficit stress produced the highest total CBD and THC concentrations, which were not significantly different from the control. Both increased water-deficit stress frequencies and the timing of water-deficit stress at different flowering stages of the plant resulted in reduced total plant biomass and inflorescence yield. Water-deficit stress at different flowering stages did not significantly affect the secondary metabolites of a plant. These findings suggest that it is possible to maximize secondary metabolites of cannabis under increased water-deficit stress intensity while reducing water use which may depend on cultivars. This can lead to increased sustainability in terms of cannabis production systems. Ultimately, optimizing stress scheduling, intensity, assessment methods, application techniques, and fertigation practices is essential for achieving a balance between biomass yield, water-use efficiency, and cannabinoid accumulation in controlled environmental systems. Induced water-deficit stress may be an effective strategy to maximize cannabinoid concentration, although results may differ by cannabis cultivar or chemotype.
Access
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