Abstract
The cultivation of medical cannabis ( Cannabis sativa L.) is expanding in controlled environments, driven by evolving governmental regulations for healthcare supply. Increasing inflorescence weight and plant specialized metabolite (PSM) concentrations is critical, alongside maintaining product consistency. Medical cannabis is grown under different spectra and photosynthetic photon flux densities (PPFD), the interaction between spectrum and PPFD on inflorescence weight and PSM attracts attention by both industrialists and scientists. Plants were grown in climate-controlled rooms without solar light, where four spectra were applied: two low-white spectra (7B-20G-73R/Narrow and 6B-19G-75R/2Peaks), and two high-white (15B-42G-43R/Narrow and 17B-40G-43R/Broad) spectra. The low-white spectra differed in red wavelength peaks (100% 660 nm, versus 50:50% of 640:660 nm), the high-white spectra differed in spectrum broadness. All four spectra were applied at 600 and 1200 μmol m -2 s -1 . Irrespective of PPFD, white light with a dual red peak of 640 and 660 nm (6B-19G-75R/2Peaks) increased inflorescence weight, compared to white light with a single red peak of 660 nm (7B-20G-73R/Narrow) (tested at P = 0.1); this was associated with higher total plant dry matter production and a more open plant architecture, which likely enhanced light capture. At high PPFD, increasing white fraction and spectrum broadness (17B-40G-43R/Broad) produced similar inflorescence weights compared to white light with a dual red peak of 640 and 660 nm (6B-19G-75R/2Peaks). This was caused by an increase of both plant dry matter production and dry matter partitioning to the inflorescences. No spectrum or PPFD effects on cannabinoid concentrations were observed, although at high PPFD white light with a dual red peak of 640 and 660 nm (6B-19G-75R/2Peaks) increased terpenoid concentrations compared to the other spectra. At low PPFD, the combination of white light with 640 and 660 nm increased photosynthetic efficiency compared with white light with a single red peak of 660nm, indicating potential benefits in light use efficiency and promoting plant dry matter production. These results indicate that the interaction between spectrum and PPFD influences plant dry matter production. Dividing the light energy in the red waveband over both 640 and 660 nm equally shows potential in enhancing photosynthesis and plant dry matter production.
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Claims 9
Claim · model-written summary
At either PPFD, dual red peak white light increased inflorescence weight versus single red peak light (tested at P = 0.1).
- Taxon
- Cannabis sativa L.
Cannabis sativae0 - Treatment
- white light with a dual red peak of 640 and 660 nm (6B-19G-75R/2Peaks)e1
- Outcome
- inflorescence weighte1
- Direction
- increasede1
- Qualifier
- tested at P = 0.1e1
- Comparator
- white light with a single red peak of 660 nm (7B-20G-73R/Narrow)e1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“cannabis ( Cannabis sativa L.)”
e1“Irrespective of PPFD, white light with a dual red peak of 640 and 660 nm (6B-19G-75R/2Peaks) increased inflorescence weight, compared to white light with a single red peak of 660 nm (7B-20G-73R/Narrow) (tested at P = 0.1)”
Claim · model-written summary
Dual red peak light was associated with higher total plant dry matter production.
- Taxon
- Cannabis sativa L.Cannabis sativat0
- Treatment
- dual red peake1
- Outcome
- total plant dry matter productione0
- Direction
- highere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“medical cannabis (Cannabis sativa L.)”
e0“this was associated with higher total plant dry matter production and a more open plant architecture”
e1“white light with a dual red peak of 640 and 660 nm (6B-19G-75R/2Peaks) increased inflorescence weight”
Claim · model-written summary
Dual red peak light was associated with a more open plant architecture.
- Taxon
- Cannabis sativa L.Cannabis sativat0
- Outcome
- plant architecturee0
- Direction
- more opene0
- Qualifier
- higher total plant dry matter productione0
Not reportedTreatment
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“medical cannabis (Cannabis sativa L.)”
e0“this was associated with higher total plant dry matter production and a more open plant architecture”
Claim · model-written summary
At high PPFD, broad high-white light produced similar inflorescence weights to dual red peak white light.
- Taxon
- Cannabis sativa L.Cannabis sativat0
- Treatment
- 17B-40G-43R/Broade0
- Outcome
- inflorescence weightse0
- Direction
- similare0
- Qualifier
- high PPFDe0
- Comparator
- 6B-19G-75R/2Peakse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“medical cannabis (Cannabis sativa L.)”
e0“At high PPFD, increasing white fraction and spectrum broadness (17B-40G-43R/Broad) produced similar inflorescence weights compared to white light with a dual red peak of 640 and 660 nm (6B-19G-75R/2Peaks)”
Claim · model-written summary
At high PPFD, broad white light increased plant dry matter production.
- Taxon
- Cannabis sativa L.Cannabis sativat0
- Outcome
- plant dry matter productione0
- Direction
- increasee0
Not reportedTreatmentComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“medical cannabis (Cannabis sativa L.)”
e0“This was caused by an increase of both plant dry matter production and dry matter partitioning to the inflorescences”
Claim · model-written summary
At high PPFD, broad white light increased dry matter partitioning to inflorescences.
- Taxon
- Cannabis sativa L.Cannabis sativat0
- Outcome
- dry matter partitioning to the inflorescencese0
- Direction
- increasee0
Not reportedTreatmentComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“medical cannabis (Cannabis sativa L.)”
e0“This was caused by an increase of both plant dry matter production and dry matter partitioning to the inflorescences”
Claim · model-written summary
Spectrum and PPFD had no observed effects on cannabinoid concentrations.
- Taxon
- Cannabis sativa L.Cannabis sativat0
- Treatment
- spectrum or PPFDe0
- Outcome
- cannabinoid concentrationse0
- Direction
- Noe0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“medical cannabis (Cannabis sativa L.)”
e0“No spectrum or PPFD effects on cannabinoid concentrations were observed”
Claim · model-written summary
At high PPFD, dual red peak white light increased terpenoid concentrations over other spectra.
- Taxon
- Cannabis sativa L.Cannabis sativat0
- Treatment
- white light with a dual red peak of 640 and 660 nm (6B-19G-75R/2Peaks)e0
- Outcome
- terpenoid concentrationse0
- Direction
- increasede0
- Qualifier
- high PPFDe0
- Comparator
- the other spectrae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“medical cannabis (Cannabis sativa L.)”
e0“at high PPFD white light with a dual red peak of 640 and 660 nm (6B-19G-75R/2Peaks) increased terpenoid concentrations compared to the other spectra”
Claim · model-written summary
At low PPFD, dual red peak light increased photosynthetic efficiency relative to single red peak light.
- Taxon
- Cannabis sativa L.Cannabis sativat0
- Treatment
- white light with 640 and 660 nme0
- Outcome
- photosynthetic efficiencye0
- Direction
- increasede0
- Qualifier
- low PPFDe0
- Comparator
- white light with a single red peak of 660nme0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“medical cannabis (Cannabis sativa L.)”
e0“At low PPFD, the combination of white light with 640 and 660 nm increased photosynthetic efficiency compared with white light with a single red peak of 660nm”
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