Effects of Drought Stress on Floral Hemp (Cannabis sativa L.) Agricultural Systems

Abstract

Hemp (Cannabis sativa L.) is a crop of renewed interest in modern agriculture. However, for it to be considered hemp and not marijuana, it must have a total THC concentration of no greater than 0.3%. Drought is a common abiotic factor that can affect many locations globally, therefore it is important to conserve water resources when possible. Drought stress is believed to affect hemp at the production and physiological levels as well as can potentially increase THC concentrations. The objective of this Master Thesis was to determine the effects of drought stress intensities and timings on yield and cannabinoid concentrations, carbon assimilation and light capture mechanisms, as well as arthropod communities. Two cultivars of hemp, BaOx and Cherry Mom were planted in a greenhouse in early July and harvested in early October of 2021 and 2022. Moderate water stresses (30-50% soil water content) were found to not affect final yields, cannabinoid concentrations, or many carbon and light capture mechanisms within the crop. However, more intense drought stresses can negatively impact these parameters. In terms of arthropods this study found drought stresses do not significantly affect insect populations, but ‘Cherry Mom’ may be more susceptible to pests. These findings suggest that it is possible to cultivate a healthy and productive hemp crop while significantly reducing water use. This can lead to increased sustainability in terms of hemp production systems.