Abstract
This study focused on the physiology, growth and antioxidant activity response of hydroponically grown lettuce (Lactuca sativa L.) under sole-source LED lighting of differing spectra. Lighting spectra were provided by differing combinations of LEDs of three different peak wavelengths, (Blue 435, Blue 450, and Red 663 nm) with ratios of B450/R663: 1.25 ± 0.1, B450/R663: 1.25 ± 0.1, and B450/R663 1:1 at two light intensities of photosynthetically active radiation (PAR) (270 μmol m−2 s−1 and 60 μmol m−2 s−1). A further experiment was conducted, in which Blue and Red LEDs were supplemented with Green (Blue 450, Red 663, and Green 520 nm) with ratios of B435/R663: 1.25 ± 0.1, B450/R663/G520: 1/0.73/0.26, and B450/R663: 1.25 ± 0.1. LED light intensities under the different spectra were adjusted to deliver the same level of PAR (270 ± 20 μmol m−2 s−1). Results from the first experiment showed that increased fraction of blue 435 nm in combination with red light at 663 nm at high irradiance enhanced the physiology of lettuce (i.e., significantly increased assimilation rate, stomatal conductance and transpiration rate) and increased the yield while having no significant effect on antioxidant activity. At the lower irradiance, the B435/R663 significantly increased antioxidant activity compared to other spectra. Results from the second experiment showed no significant effect of the spectra of LEDs on the physiology and yield of lettuce, but antioxidant activity was very significantly induced by B450/R663 at the ratio of 1.25 ± 0.1. However, the amount was still less than that obtained by B435/R663 1.25 ± 0.1 from the first experiment. This study indicates that LED light with a spectrum of B435/R663 at a ratio of 1.25 ± 0.1 significantly improves lettuce yield and antioxidant activity.
Abstract from the paper’s OpenAlex record; open copy licensed cc-by. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 8
Claim · model-written summary
At high irradiance, more blue 435 nm with red light increased lettuce assimilation, stomatal conductance and transpiration.
- Taxon
- lettuce
Lactuca sativae0 - Treatment
- increased fraction of blue 435 nm in combination with red light at 663 nm at high irradiancee0
- Outcome
- assimilation rate, stomatal conductance and transpiration ratee0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“increased fraction of blue 435 nm in combination with red light at 663 nm at high irradiance enhanced the physiology of lettuce (i.e., significantly increased assimilation rate, stomatal conductance and transpiration rate)”
Claim · model-written summary
At high irradiance the blue 435 nm and red 663 nm spectrum increased lettuce yield.
- Taxon
- lettuceLactuca sativae0
- Treatment
- increased fraction of blue 435 nm in combination with red light at 663 nm at high irradiancee0
- Outcome
- yielde0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“increased fraction of blue 435 nm in combination with red light at 663 nm at high irradiance enhanced the physiology of lettuce (i.e., significantly increased assimilation rate, stomatal conductance and transpiration rate) and increased the yield”
Claim · model-written summary
At high irradiance that spectrum did not significantly affect antioxidant activity.
- Taxon
- lettuceLactuca sativae0
- Treatment
- increased fraction of blue 435 nm in combination with red light at 663 nm at high irradiancee0
- Outcome
- antioxidant activitye0
- Direction
- no significant effecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“increased fraction of blue 435 nm in combination with red light at 663 nm at high irradiance enhanced the physiology of lettuce (i.e., significantly increased assimilation rate, stomatal conductance and transpiration rate) and increased the yield while having no significant effect on antioxidant activity”
Claim · model-written summary
At lower irradiance B435/R663 increased antioxidant activity over other spectra.
- Taxon
- LettuceLactuca sativat0
- Treatment
- B435/R663e0
- Outcome
- antioxidant activitye0
- Direction
- increasede0
- Comparator
- other spectrae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“At the lower irradiance, the B435/R663 significantly increased antioxidant activity compared to other spectra”
t0“Lettuce”
Claim · model-written summary
In the second experiment LED spectra did not significantly affect lettuce physiology or yield.
- Taxon
- lettuceLactuca sativae0
- Treatment
- spectra of LEDse0
- Outcome
- physiology and yielde0
- Direction
- no significant effecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“no significant effect of the spectra of LEDs on the physiology and yield of lettuce”
Claim · model-written summary
In the second experiment B450/R663 at 1.25 ± 0.1 strongly induced lettuce antioxidant activity.
- Taxon
- LettuceLactuca sativat0
- Treatment
- B450/R663 at the ratio of 1.25 ± 0.1e0
- Outcome
- antioxidant activitye0
- Direction
- inducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“antioxidant activity was very significantly induced by B450/R663 at the ratio of 1.25 ± 0.1”
t0“Lettuce”
Claim · model-written summary
B450/R663 produced less antioxidant activity than B435/R663 1.25 ± 0.1 in the first experiment.
- Taxon
- LettuceLactuca sativat0
- Treatment
- B450/R663e1
- Outcome
- antioxidant activitye1
- Direction
- lesse0
- Comparator
- B435/R663 1.25 ± 0.1e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the amount was still less than that obtained by B435/R663 1.25 ± 0.1 from the first experiment”
e1“antioxidant activity was very significantly induced by B450/R663 at the ratio of 1.25 ± 0.1”
t0“Lettuce”
Claim · model-written summary
The authors conclude B435/R663 at 1.25 ± 0.1 improves lettuce yield and antioxidant activity.
- Taxon
- lettuceLactuca sativae0
- Treatment
- B435/R663 at a ratio of 1.25 ± 0.1e0
- Outcome
- lettuce yield and antioxidant activitye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“LED light with a spectrum of B435/R663 at a ratio of 1.25 ± 0.1 significantly improves lettuce yield and antioxidant activity”
The same questions in other papers
light · physiology: gas exchange · Lactuca sativa (garden lettuce)Positive and negative results
5 papers in the same direction as this paper · 3 in the opposite direction · 1 reporting no difference from an alternative
- no effect
- negative
- no effect
6 papers more in this group
See all 10 papers →light · quality: phytochemicals · Lactuca sativa (garden lettuce)Positive and negative results
7 papers in the same direction as this paper · 43 in the opposite direction
- positive
- positive
- positive
47 papers more in this group
See all 51 papers →light · yield · Lactuca sativa (garden lettuce)Positive and negative results
52 papers in the same direction as this paper · 15 in the opposite direction · 3 reporting no difference from an alternative
- positive
- no effect
- no effect
67 papers more in this group
See all 71 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.