An Evaluation of the Growing Environment on the Production of Secondary Metabolites in Cannabis Plants

We were interested in determining the effect if any on growing conditions on clones of the same cannabis plant. In particular we were interested in the difference between plants grown outdoors in a highly dynamic environment and those grown indoors in a tightly controlled environment. We took 4 strains of cannabis and split clones between indoor and outdoor growing conditions. The dried cured flowers were analyzed by LCUV, GCFID, and ICPMS to measure specific terpene, cannabinoid, and heavy metals content. These flower samples were also analyzed using a TOF. The TOF data was processed using principal component analysis software which was able to identify component trends distinguishing between indoor and outdoor grows as well as strain specific component trends. Outdoor grows showed a bias towards producing more complicated secondary metabolites while indoor showed a bias towards simpler species. In all cases terpene potencies were elevated in outdoor grown plants while THCa potencies were elevated in most outdoor grown plants. The only plants with measurable heavy metal content were the indoor grown plants. These results could have implications for cultivating cannabis for novel therapeutic components as well as the relative safety and quality of cannabis cultivation approach.

Learning Objectives:

1. Explain how the choice of cultivation impacts secondary metabolites.

2. Describe how combining targeted approaches with untargeted approaches provides a bigger picture on the impact of growing environments.