Abstract
SummaryThe effect of pre-harvest light intensity on the quality of hydroponically-grown lettuce (Lactuca sativa var. capitata L.) was studied by growing lettuce under 48 h of continuous illumination delivered by red- or blue-light-emitting diodes (LEDs) with a red:blue ratio of 4.0. Four light intensity treatments (50, 100, 150, or 200 µmol m–2 s–1) were applied. The results showed that the nitrate concentrations in lettuce shoots decreased significantly after treatment with 48 h of continuous light, while the contents of soluble sugars and vitamin C increased substantially. It was observed that the effect of pre-harvest short-duration continuous light (PSCL) on improving lettuce quality was significantly influenced by the intensity of the light. The decrease in nitrate concentration and the increases in soluble sugars and vitamin C contents were relatively low at a light intensity of 50 µmol m–2 s–1, but increased gradually as the light intensity increased from 50 µmol m–2 s–1 to 200 µmol m–2 s–1. However, the marginal benefit of increased light intensity in lowering nitrate concentration and increaseing vitamin C content declined rapidly when the light intensity increased beyond 100 µmol m–2 s–1. In conclusion, PSCL offers an effective method by which to improve the quality of lettuce, and a light intensity of between 100 µmol m–2 s–1 – 150 µmol m–2 s–1 is the economic optimum.
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Claims 6
Claim · model-written summary
48 h continuous light significantly decreased lettuce shoot nitrate concentrations.
- Taxon
- lettuce
Lactuca sativae0 - Organ / stage
- shootse0
- Treatment
- 48 h of continuous lighte0
- Outcome
- nitrate concentrationse0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the nitrate concentrations in lettuce shoots decreased significantly after treatment with 48 h of continuous light”
Claim · model-written summary
48 h continuous light substantially increased lettuce soluble sugars and vitamin C contents.
- Taxon
- lettuceLactuca sativae0
- Treatment
- 48 h of continuous lighte0
- Outcome
- contents of soluble sugars and vitamin Ce0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the nitrate concentrations in lettuce shoots decreased significantly after treatment with 48 h of continuous light, while the contents of soluble sugars and vitamin C increased substantially”
Claim · model-written summary
Light intensity significantly influenced the quality improvement from preharvest continuous light.
- Taxon
- lettuceLactuca sativae0
- Treatment
- intensity of the lighte0
- Outcome
- lettuce qualitye0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the effect of pre-harvest short-duration continuous light (PSCL) on improving lettuce quality was significantly influenced by the intensity of the light”
Claim · model-written summary
Nitrate reduction and soluble sugar and vitamin C increases were low at 50 and gradually greater as intensity rose to 200 µmol m–2 s–1.
- Taxon
- lettuceLactuca sativat0
- Treatment
- light intensity increased from 50 µmol m–2 s–1 to 200 µmol m–2 s–1e0
- Outcome
- decrease in nitrate concentration and the increases in soluble sugars and vitamin C contentse0
- Direction
- increased graduallye0
- Comparator
- 50 µmol m–2 s–1e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The decrease in nitrate concentration and the increases in soluble sugars and vitamin C contents were relatively low at a light intensity of 50 µmol m–2 s–1, but increased gradually as the light intensity increased from 50 µmol m–2 s–1 to 200 µmol m–2 s–1.”
t0“lettuce”
Claim · model-written summary
The marginal nitrate and vitamin C benefits declined rapidly above 100 µmol m–2 s–1.
- Taxon
- lettuceLactuca sativat0
- Treatment
- light intensity increased beyond 100 µmol m–2 s–1e0
- Outcome
- marginal benefite0
- Direction
- declined rapidlye0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the marginal benefit of increased light intensity in lowering nitrate concentration and increaseing vitamin C content declined rapidly when the light intensity increased beyond 100 µmol m–2 s–1”
t0“lettuce”
Claim · model-written summary
The authors recommend 100–150 µmol m–2 s–1 as the economic optimum for effective lettuce quality improvement with PSCL.
- Taxon
- lettuceLactuca sativae0
- Treatment
- PSCLe0
- Outcome
- economic optimume0
- Value
- 100 µmol m–2 s–1 – 150 µmol m–2 s–1e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“PSCL offers an effective method by which to improve the quality of lettuce, and a light intensity of between 100 µmol m–2 s–1 – 150 µmol m–2 s–1 is the economic optimum”
The same questions in other papers
light · nutrient: content · Lactuca sativa (garden lettuce)Positive and negative results
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- positive
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See all 20 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.