Evaluating Growth, Biomass and Cannabinoid Profiles of Floral Hemp Varieties under Different Planting Dates in Organic Soils of Florida

Abstract

Hemp production has been permitted as a new agricultural commodity in Florida and may serve as a potential rotational crop. Field trials were conducted in the Everglades Agricultural Region with multiple varieties planted at different dates. Data were collected on plant growth parameters, final biomass at harvest, and temporal cannabidiol (CBD) and Δ-9-tetrahydrocannabinol (THC) content in developing flowers. Results showed that at the United States Sugar Corporation (USSC) location, the BaOX variety had higher biomass compared to other varieties and at Everglades Research and Education Center (EREC), varieties ACDC and Cherry wine recorded the highest biomass compared to other varieties. Moreover, plant growth parameters such as plant height, canopy cover and SPAD were significantly affected by variety and planting date. Total CBD and THC content in plants increased over time for most varieties except for Early bird and Cherry abacus under second planting. There was a significantly high correlation between total CBD and THC content (R2 = 0.75 to 0.98, slope = 16.8 to 22.8). The THC content in most varieties exceeded the legal limit of 0.3% at some stage of the growing season. The results of this study indicate that the variety performance was largely affected by genetics compared to the planting date.