A field study was conducted to observe the natural development of cannabinoids in three daylength sensitive industrial hemp varieties Bubba Kush (BK), Emerald Flower (EF), and Golden Sunset (GS). Plants were configured in a randomized block design with 3 replications. Once 50% of the plants within a variety reached reproductive growth, plants were sampled weekly until senescence and analyzed through a HPLC-UV/DAD. The results from the study indicate that all three varieties of industrial hemp tested in field study reached reproductive growth within the first week of transplanting. This is due to a 12-hour day-length at the time and the varieties being daylight sensitive. Data suggests that total CBD and THC reached their peak concentration at 5-7 weeks after anthesis. After this period, the degradation and transformation of cannabinoids occurs, causing a decrease in concentration. The federal limit of total THC was reached in the BK variety three weeks post-anthesis, while EF and GS reached their limit at 5-7 weeks. This dramatically increased the accumulation time of total CBD within EF and GS. Although the fluctuation of cannabinoids was dynamic within each variety, this study provides information and insights on the proper management and cultivation of industrial hemp in South Florida
