Articles
Effect of light intensity and branch origin position on Cannabis sativa inflorescence density and THC content
Article number
1426_18
Pages
125 – 130
Language
English
Abstract
To investigate the effects of light intensity and branch origin position on the inflorescence density and Δ9-tetrahydrocannabinol (THC) content of Cannabis sativa (cannabis), ‘Blue Dream’ plants were grown in a commercial greenhouse in southwestern Ontario, Canada from vegetative stage to inflorescence maturity.
There were two groups of plants with one group trained and one group not trained as the control.
A bottom branch originating from the same position for all the experimental plants was selected and marked along with the inflorescence of the main branch (top). For the trained plants, the inflorescences of the bottom branches and the inflorescence of the main branch were brought to have the same heights using gentle force and clips, resulting both the top and bottom inflorescences having experienced the same light intensities during the experiment.
The untrained plants were grown in their natural form with the top inflorescence higher than the bottom inflorescence resulting in the bottom having lower light intensity than the top.
Plants were harvested at maturity and all the inflorescence densities and THC contents were measured.
There were no differences in THC contents (averaged 17.2%) among all the bottom and top inflorescences for both trained and not trained plants, which indicates that neither light intensity nor branch origin position affected the inflorescence THC content.
There was no difference in the densities of the top and bottom inflorescences for the trained plants, but the densities of the bottom inflorescences were lower than the tops for the untrained control plants, which suggests that light intensity is important for producing inflorescence with high density.
The results of this study can be used in guiding cannabis plant training and lighting, especially in controlled environment cannabis cultivation.
There were two groups of plants with one group trained and one group not trained as the control.
A bottom branch originating from the same position for all the experimental plants was selected and marked along with the inflorescence of the main branch (top). For the trained plants, the inflorescences of the bottom branches and the inflorescence of the main branch were brought to have the same heights using gentle force and clips, resulting both the top and bottom inflorescences having experienced the same light intensities during the experiment.
The untrained plants were grown in their natural form with the top inflorescence higher than the bottom inflorescence resulting in the bottom having lower light intensity than the top.
Plants were harvested at maturity and all the inflorescence densities and THC contents were measured.
There were no differences in THC contents (averaged 17.2%) among all the bottom and top inflorescences for both trained and not trained plants, which indicates that neither light intensity nor branch origin position affected the inflorescence THC content.
There was no difference in the densities of the top and bottom inflorescences for the trained plants, but the densities of the bottom inflorescences were lower than the tops for the untrained control plants, which suggests that light intensity is important for producing inflorescence with high density.
The results of this study can be used in guiding cannabis plant training and lighting, especially in controlled environment cannabis cultivation.
Publication
Authors
S. Dam, Y. Zheng
Keywords
branch origin, cannabis, inflorescence density, light intensity, plant training, THC, CEA
Groups involved
- Division Precision Horticulture and Engineering
- Division Greenhouse and Indoor Production Horticulture
- Working Group Nettings in Horticulture (subgroup of Protected Cultivation in Mild Winter Climates)
- Working Group Light in Horticulture
- Working Group Organic Greenhouse Horticulture
- Working Group Vegetable Grafting
- Working Group Modelling Plant Growth, Environmental Control, Greenhouse Environment
- Working Group Protected Cultivation, Nettings and Screens for Mild Climates
- Working Group Computational Fluid Dynamics in Agriculture
- Working Group Design and Automation in Integrated Indoor Production Systems
- Working Group Mechanization, Digitization, Sensing and Robotics
- Working Group Greenhouse Environment and Climate Control
- Division Landscape and Urban Horticulture
- Commission Agroecology and Organic Farming Systems
- Division Vegetables, Roots and Tubers
- Working Group Vertical Farming
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