Cannabis is a unique plant to study from a photo-biological perspective, because it can take on more light than most commercial crops with almost no ill effects. In fact, because cannabis produces more of its valuable commodities when it is pushed to its limits, our team recently discussed a series of revolutionary insights in a webinar discussing the Impact of Spectra on Indoor & Greenhouse Cannabis Production.

In collaboration with Wageningen University & Research and Compassionate Cultivation, Fluence is proud to announce the findings of a series of groundbreaking photobiology research studies examining how light spectra affect cannabis growth and development. These studies are the first of their kind and provide key insights for commercial cannabis growers looking to maximize production, improve product quality and optimize efficiencies in their farms.

Commercial cannabis cultivation with LED grow lights, advanced cannabis lighting technology.

Desvelar los secretos de la fotobiología del cannabis

Cannabis is a high value crop in commercial agriculture, but it currently has very limited scientific documentation to guide its commercialization. Because of this, the Fluence research team has been focused on discovering insights about cannabis that are immediately actionable. Research was conducted in two studies focused on how lighting can be used to further enhance the desirable aspects of cannabis in commercial greenhouse and indoor settings.

Each experiment was carefully designed to examine the effects of broad spectrum white light, broad spectrum pink light and narrow band red/blue light deployed on the VYPR 3p Series. Each light treatment is distinct in spectral composition. The purpose of examining each of these treatments is to further understand which light spectra is most appropriate for corresponding greenhouse or indoor environments for Type I cannabis (high in THC), Type III cannabis (high in CBD) and Type II cannabis (a balance of THC and CBD).

Figura 1: Espectros de luz superior de fluencia utilizados en estudios de investigación. Haga clic para ampliar.

Spectral power distribution chart by Fluence showcasing normalized photosynthetic photon flux (PPF) across 380-780 nm wavelengths, emphasizing green-yellow and red regions for optimized cannabis cultivation.

Spectral power chart shows photosynthetic photon flux for LED grow lights in cannabis cultivation.

Spectral power distribution chart of LED light spectra by Fluence, Austin, TX – optimized for cannabis cultivation. Highlights peak at 680nm with range from 360nm to 730nm for enhanced crop production in controlled environments.
Spectral power chart for LED grow lights in cannabis cultivation, peak at 680 nm, small peaks at 450 nm.
Fluence LED grow light spectral power distribution chart for cannabis cultivation; highlights peak at 680 nm; normalized photometric photon flux range from 380 nm to 730 nm; optimized for crop production.
Cannabis lighting spectrum chart with 680 nm peak, ideal for LED grow lights in commercial cannabis cultivation.

Through these studies, Fluence was able to determine eight key insights in manipulating the development of cannabis that can have a profound effect on commercial cannabis production when applied correctly:

      1. Figura 2: Impacto de la luz roja en la producción de terpenos

        En primer lugar, Fluence verificó que en algunos cultivares, un menor porcentaje de luz roja se correlaciona con un aumento de las concentraciones de cannabinoides.

      2. Y lo que es aún más interesante, la luz roja puede utilizarse para manipular las proporciones de terpenos en el cannabis (véase la Figura 2).
      3. A bajas intensidades de luz suplementaria en un invernadero, todos los espectros Fluence probados alcanzan rendimientos comparables.
      4. En un ambiente interior -donde las fuentes de luz emiten a intensidades más elevadas- los espectros Broad White R4 y R8 dieron mejores resultados que el R6.
      5. En interiores, el rendimiento de R4 fue hasta un 17% superior al de la siguiente mejor solución espectral en determinados cultivares de cannabis de tipo I con THC elevado.
      6. En interiores, el R4 produjo sistemáticamente mayores rendimientos y tiene la ventaja añadida de no provocar fotoblanqueo, mientras que los espectros como el R8, que tienen una fracción considerablemente mayor de luz roja, inducen fotoblanqueo.
      7. En ambos tipos de entornos, la sensibilidad del espectro depende del cultivar.
      8. Por último, al aplicar estos conocimientos al entorno de un cultivador, la iluminación R4 y R8 puede utilizarse para aumentar significativamente el margen bruto estimado del cultivador.

Estos conocimientos son muy significativos porque pueden ser aprovechados inmediatamente por los cultivadores que buscan producir efectos químicos y morfológicos específicos en sus cultivos de cannabis. En ambos estudios, Fluence fue capaz de validar el hecho de que los espectros de luz pueden tener un impacto significativo en los cultivos de cannabis, tanto si se cultivan en interior como en invernadero.

Cannabis grow room: LED grow lights for cannabis seedlings, worker in commercial cannabis cultivation using advanced lighting technology.

¿Qué significa esto para su cultivo?

A primary benefit of the webinar is how growers were able to address their questions in real-time, learning exactly how they can leverage Fluence’s research to impact plant response and productivity in their current environments. A few examples of questions asked during the webinar include:

Q: What is the right spectrum for my cannabis crops?

A: This is highly dependent on your cultivation goals. As evidenced by the results above, cannabinoids, terpenes and yield are all affected by spectra choice, to varying degrees. Whether you are looking to sell your crops as flower or extract, Fluence can help you determine the right spectra to maximize your investment into lighting.

Q: Should I be using UV or far-red lighting?

A: While there is a lot of interest outside of PAR, there is a clear misconception of the value of these light sources and their impact on yield or plant chemistry. Far-red light is good for eliciting a shade avoidance response, and it will give cannabis plants a larger canopy and stretch out the plants, which can be good for cultivars that have dense foliage. The Fluence research team will discuss this topic in more detail in an upcoming webinar.

Q: What is the impact on plant morphology between spectra?

A: In indoor settings, no noticeable evidence of stretch occurred. However, in the greenhouse environment, there was significant canopy expansion under the R8 light treatment. Our working theory is that a lower potting density in the greenhouse environment enabled the plants to spread and stretch more in that study. In the indoor study, photobleaching was also observed under spectra containing higher levels of red-light, negatively impacting market value of the harvested bud.

Q: What is the appropriate light level for cannabis crops in my region?”

A: This study utilized a PPFD of 480-500 in the greenhouse environment and a PPFD of 1,100 in the indoor environment. We have seen many growers push light levels well beyond these metrics with success but the tolerance for high light intensity can be cultivar dependent. If you are considering supplemental lighting in a greenhouse it is always best to measure the transmissivity of your greenhouse and consult with a Fluence specialist to develop a lighting strategy for your targeted PPFD based on your annual DLI.

A number of other questions including the reasons why photobleaching occurs, the importance of DLI measurements, how light affects plant morphology and a deep-dive into how each experiment was conducted were also addressed during the webinar.

If you are interested in learning more about Fluence research, or if you would like to gain access to the webinar, contact a Fluence sales representative directly.

For more research insights and best practices that might be relevant to your business, we encourage you to tune into our ongoing webinar series as well.