Meeting the Challenges of Greenhouse Production and Propagation of Cannabis sativa

Abstract

With the passing of the 2018 Farm Bill, it was federally legal to grow hemp, Cannabis sativa L. but still regulated on a state-by-state basis. In 2019, Alabama legalized the production of hemp. Since hemp is such a new crop, there is little published information about the production of C. sativa. Two separate research studies were carried out at the Auburn University Ornamental Horticulture Research Center in Mobile, AL to address concerns of Alabama hemp growers. The first study evaluated a plant growth regulator (PGR), uniconazole as a pre transplant liner soak on C. sativa L. ‘Berry Blossom’ hemp liners. In December of 2021 four treatment rates (0, 1, 3, and 5 mg/L uniconazole) and four different root-ball soak times (0, 30, 75, and 120 seconds) were evaluated in regards to plant growth. Results showed that there were no differences between rate and soak time. The trial was repeated in June of 2022 with soak time removed as a variable. Results showed plants receiving 3 ppm uniconazole were 1.3 times greater in calculated yield per area when compared to the untreated control. The second study examined Tetranychus urticae, the two-spotted spider mite (TSSM), one of the most common pest found in greenhouse Cannabis crops. Three biological pesticides, one non-biological, and an untreated control were evaluated for efficacy in two trials.The results from both trials showed that there is potential to reduce TSSM populations when using Grandevo® and Venerate®.