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Potency of Cannabis Grown Under LED and HPS Lights
Professor DeBacco

Research Article
Jenkins, M. W., & Livesay, C. B. (2021). Photosynthetic Performance and Potency of Cannabis sativa L. Grown under LED and HPS Illumination. Agricultural Sciences, 12(03), 293.

The Great Debate…
However, most people do not consider this to be a debate, they feel it is LED lights or nothing.

Comparing All Lights in Study
ePapillion 1000 w Double Ended HPS
Fluence Bioengineering (now Fluence by Osram) SPYDRxPLUS LED
BIOS (Icarus Gi2)
California Light Works (SolarSystem 1100)
Then There Were Two…
ePapillion 1000 w Double Ended HPS
Fluence Bioengineering (now Fluence by Osram) SPYDRxPLUS LED

The first part of this study was to evaluate leading LED light manufacturers/models and identify which option provides the most uniform distribution of light at the leaf and canopy as this is an important factor to producing a consistent end product.
Fluence by Osram SPYRD xPLUS model clearly demonstrated optimal light distribution, photosynthetic response and also maintained leaf temperature within an optimal range to achieve maximum photosynthetic rates.

Lightings Impact on THCA Levels
In this study, all cannabis cultivars grown under LED lights yielded an increase in THCA% with an average increase of 5.39% (mean of 25.06% THCA under LED versus 19.67% under HPS)

What Does This Mean For Growers?
Many growers would think that LED lights will yield them more THCA and while this study did show there are other factors that must be taken into consideration.
With indoor facilities there are other environmental control factors that need to be optimized to ensure a quality harvest.
THCA and Lighting
To break the 30% or even 35% total THC theoretical barrier one does not need LED lighting as this can be done with HPS lights used during flowering.

LED lighting can also help this, but all factors must be taken into consideration especially coverage area related to PAR readings.

Grower Considerations
Sure LED light technology may be the way of the future, but at the current time taking into full cost of initially purchasing, ownership and number of fixture needed HPS is still price competitive.
LED lights do offer the advantage of being full spectrum so growers can see the plants “true” without the need for filtering lenses, and there may be some (beneficial) wavelengths of light that can aid in cannabis plants ability to produce certain compounds at greater concentrations.
But this does not mean HPS lights are useless and if available to growers they should use them.

Take Home Message
Many companies produce LED lights, but in general…
Good LED lights are not cheap, and cheap LED lights are not good.
HPS lights can still produce quality cannabis and for the cost are worth a serious consideration by more growers.

Link to Lecture Slides:

*Due to the description character limit the full work cited for “Potency of Cannabis Grown Under LED and HPS Lights” can be viewed at…