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Effect of Electrical Lighting Power and Irradiance on Indoor-Grown Cannabis Potency and Yield

NCJ Number
240266
Journal
Journal of Forensic Sciences Volume: 57 Issue: 3 Dated: May 2012 Pages: 618-622
Author(s)
David J. Potter Ph.D.; Paul Duncombe Ph.D.
Date Published
May 2012
Length
5 pages
Annotation
The floral development and potencies of cannabis plants were compared when grown indoors under high-pressure sodium lamps.
Abstract
The floral development and potencies [^9-tetrahydrocannabinol (THC) contents] of cannabis plants were compared when grown indoors under high-pressure sodium lamps consuming electrical power at three densities (270, 400, and 600 W/m2). After a 3-week vegetative phase, plants were grown for 8 weeks, with lamps maintaining an artificial day length of 12 h. Foliar and floral yields were measured. Gas chromatography was used to measure the content of the psychoactive cannabinoid THC. Mean yields per unit of electrical power in each lighting regime ranged from 0.9 to 1.6 g/W, the highest being achieved in the lowest irradiance regime. The individual potencies of the separated leaf and flower materials were not affected by increasing irradiance. However, there was a corresponding increase in the overall potency of the aerial plant tissue. This was because of the plants in brighter conditions producing a higher proportion of floral material. Abstract published by arrangement with John Wiley & Sons.