Abstract
Understanding crop responses to the light spectrum is critical for optimal indoor production. Far-red light is of particular interest, because it can accelerate growth through both physiological and morphological mechanisms. However, the optimal amount of supplemental far-red light for indoor lettuce production is yet to be quantified. Lettuce ‘Cherokee’, ‘Green SaladBowl’, and ‘Little Gem’ were grown under 204 µmol·m−2·s−1 warm-white light-emitting diodes (LEDs) with supplemental far-red ranging from 5.3 to 75.9 µmol·m−2·s−1. Supplemental far-red light increased canopy light interception 5 days after the start of far-red light treatment (DAT) for ‘Green SaladBowl’ and ‘Little Gem’ and 7 DAT for ‘Cherokee’. The increase in light interception was no longer evident after 12 and 16 DAT for ‘Green SaladBowl’ and ‘Little Gem’, respectively. We did not find evidence that supplemental far-red light increased leaf-level photosynthesis. At the final harvest, shoot dry weights of ‘Cherokee’ and ‘Little Gem’ increased by 39.4% and 19.0%, respectively, while ‘Green SaladBowl’ was not affected. In conclusion, adding far-red light in indoor production increased light interception during early growth and likely increased whole plant photosynthesis thus growth, but those effects were cultivar-specific; the increase in dry weight was linear up to 75.9 µmol·m−2·s−1 far-red light.
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Claims 11
Claim · model-written summary
Far-red light increased canopy light interception at 5 DAT in Green SaladBowl.
- Taxon
- Lettuce
Lactuca sativat0 - Material
- ‘Green SaladBowl’e0
- Treatment
- Supplemental far-red lighte0
- Outcome
- canopy light interceptione0
- Direction
- increasede0
- Qualifier
- 5 days after the start of far-red light treatment (DAT)e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Supplemental far-red light increased canopy light interception 5 days after the start of far-red light treatment (DAT) for ‘Green SaladBowl’”
t0“Lettuce”
Claim · model-written summary
Far-red light increased canopy light interception at 5 DAT in Little Gem.
- Taxon
- LettuceLactuca sativat0
- Material
- ‘Little Gem’e0
- Treatment
- Supplemental far-red lighte0
- Outcome
- canopy light interceptione0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Supplemental far-red light increased canopy light interception 5 days after the start of far-red light treatment (DAT) for ‘Green SaladBowl’ and ‘Little Gem’”
t0“Lettuce”
Claim · model-written summary
Far-red light increased canopy light interception at 7 DAT in Cherokee.
- Taxon
- LettuceLactuca sativat0
- Material
- ‘Cherokee’e0
- Treatment
- far-red lightt0
- Outcome
- light interceptione1
- Qualifier
- 7 DATe0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“and 7 DAT for ‘Cherokee’.”
t0“Far-Red Light Effects on Lettuce Growth and Morphology in Indoor Production Are Cultivar Specific”
e1“Supplemental far-red light increased canopy light interception 5 days after the start of far-red light treatment (DAT) for ‘Green SaladBowl’”
Claim · model-written summary
The interception increase was no longer evident at 12 DAT for Green SaladBowl.
- Taxon
- LettuceLactuca sativat0
- Material
- ‘Green SaladBowl’e0
- Outcome
- increase in light interceptione0
- Direction
- no longer evidente0
- Qualifier
- 12 and 16 DATe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The increase in light interception was no longer evident after 12 and 16 DAT for ‘Green SaladBowl’ and ‘Little Gem’, respectively.”
t0“Lettuce”
Claim · model-written summary
The interception increase was no longer evident at 16 DAT for Little Gem.
- Taxon
- LettuceLactuca sativat0
- Material
- ‘Little Gem’e0
- Outcome
- increase in light interceptione0
- Direction
- no longer evidente0
- Qualifier
- 12 and 16 DATe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The increase in light interception was no longer evident after 12 and 16 DAT for ‘Green SaladBowl’ and ‘Little Gem’, respectively.”
t0“Lettuce”
Claim · model-written summary
There was no evidence of increased leaf-level photosynthesis from far-red light.
- Taxon
- LettuceLactuca sativat0
- Treatment
- supplemental far-red lighte0
- Outcome
- leaf-level photosynthesise0
- Direction
- did not find evidencee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“We did not find evidence that supplemental far-red light increased leaf-level photosynthesis.”
t0“Lettuce”
Claim · model-written summary
Cherokee shoot dry weight increased 39.4% at final harvest.
- Taxon
- LettuceLactuca sativat0
- Material
- ‘Cherokee’e0
- Treatment
- far-red lightt0
- Outcome
- shoot dry weightse0
- Direction
- increasede0
- Value
- 39.4%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“At the final harvest, shoot dry weights of ‘Cherokee’ and ‘Little Gem’ increased by 39.4% and 19.0%, respectively”
t0“Far-Red Light Effects on Lettuce Growth and Morphology in Indoor Production Are Cultivar Specific”
Claim · model-written summary
Little Gem shoot dry weight increased 19.0% at final harvest.
- Taxon
- LettuceLactuca sativat0
- Material
- ‘Little Gem’e0
- Treatment
- far-red lightt0
- Outcome
- shoot dry weightse0
- Direction
- increasede0
- Value
- 19.0%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“At the final harvest, shoot dry weights of ‘Cherokee’ and ‘Little Gem’ increased by 39.4% and 19.0%, respectively”
t0“Far-Red Light Effects on Lettuce Growth and Morphology in Indoor Production Are Cultivar Specific”
Claim · model-written summary
Green SaladBowl shoot dry weight was not affected.
- Taxon
- LettuceLactuca sativat0
- Material
- ‘Green SaladBowl’e0
- Treatment
- far-red lightt0
- Outcome
- dry weighte1
- Direction
- not affectede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“while ‘Green SaladBowl’ was not affected.”
t0“Far-Red Light Effects on Lettuce Growth and Morphology in Indoor Production Are Cultivar Specific”
e1“At the final harvest, shoot dry weights of ‘Cherokee’ and ‘Little Gem’ increased by 39.4% and 19.0%, respectively”
Claim · model-written summary
The authors inferred that greater early interception likely increased whole-plant photosynthesis and growth.
- Taxon
- LettuceLactuca sativat0
- Treatment
- far-red lighte0
- Outcome
- whole plant photosynthesis thus growthe0
- Qualifier
- increased light interception during early growthe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“adding far-red light in indoor production increased light interception during early growth and likely increased whole plant photosynthesis thus growth”
t0“Lettuce”
Claim · model-written summary
Dry-weight gains were linear through 75.9 µmol·m−2·s−1 far-red light.
- Taxon
- LettuceLactuca sativat0
- Treatment
- far-red lighte0
- Outcome
- increase in dry weighte0
- Direction
- lineare0
- Value
- 75.9 µmol·m−2·s−1e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the increase in dry weight was linear up to 75.9 µmol·m−2·s−1 far-red light.”
t0“Lettuce”
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