Lighting Strategies for the Flowering Stage of Indoor Cannabis Production

Rodriguez Morrison, Victoria
Journal Title
Journal ISSN
Volume Title
University of Guelph

This thesis investigated the effects of light intensity (LI) and ultraviolet (UV) radiation on indoor cannabis production during the flowering stage. When plants grew under LI ranging from 120 to 1800 μmol·m–2·s–1 provided by light emitting diodes (LEDs), inflorescence yield increased linearly as LI increased up to 1800 μmol·m–2·s–1. Apical inflorescence density and terpene concentration increased linearly over the range of LIs evaluated. When plants were grown under 400 μmol·m–2·s–1 supplemented with UV (peak wavelength of 287 nm) levels from 0.01 to 0.8 μmol·m–2·s–1, for 3.5 h·d–1, there were no changes in total Δ9-tetrahydrocannabinol or total cannabidiol concentrations. The severity of UV-induced cannabis morphology and physiology symptoms worsened as UV exposure level increased. The light response models developed in this thesis can be used to determine the optimum LI for a production environment, but caution should be used when exposing cannabis to UV radiation.

cannabis, potency, indoor, sole source, light emitting diode, ultraviolet, PPFD, light response curve, light intensity, cannabinoid, terpene, secondary metabolites