Abstract
The greenhouse industry is interested in light emitting diodes (LEDs) as a light source supplement to solar light to improve plant growth and development. Before LEDs can be adopted as supplemental light for greenhouse crops, plant responses to LED spectral quality need to be investigated. Tomato and cucumber seedlings were grown under different supplemental blue and red photon flux ratios (B:R ratios) under high (16-19 mol m–2 d –1) and low (5-9 mol m–2 d–1 ) solar daily light integrals (DLIs). The supplemental daily light integral was 3.6 mol m–2 d–1 . A treatment without supplemental light served as a control. Both tomato and cucumber seedlings had increased growth rate and improved morphology when grown under the supplemental LED light compared to the control. However, no significant differences were observed for any growth and morphological parameters measured in this study between the different B:R ratios for both cucumber and tomato transplants under high DLI conditions. Cucumber seedlings showed a tendency to decrease dry mass, leaf number and leaf area under low DLI conditions with increasing B:R ratio. Tomato seedlings did not show any differences between the different B:R ratios under low DLI conditions. Seedlings growth and morphology under supplemental LED light were compared to those under supplemental high pressure sodium (HPS) light. Cucumber seedlings under supplemental HPS light had greater shoot dry mass than those under the supplemental red LED light. Tomato shoot dry mass showed no differences between the HPS and red LED supplemental light treatments. Cucumber seedlings were also grown under supplemental LED pulsed lighting and supplemental LED continuous lighting. Cucumber seedlings showed no differences in shoot dry mass and net photosynthetic rate between the treatments. Collectively, these studies concluded that red LED is preferred for supplemental lighting and the increase of blue light does not offer any benefits unless the efficiency of blue LEDs largely exceeds the red LEDs. The results of this research can be used for fixture development by LED manufactures and as a decision making tool for the adoption of supplemental LED lighting by greenhouse growers.
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Claims 13
Claim · model-written summary
Tomato seedlings increased growth rate under supplemental LED light
- Taxon
- tomato
Solanum lycopersicume0 - Treatment
- supplemental LED lighte0
- Outcome
- growth ratee0
- Direction
- increasede0
- Comparator
- controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Both tomato and cucumber seedlings had increased growth rate and improved morphology when grown under the supplemental LED light compared to the control”
Claim · model-written summary
Tomato seedlings improved morphology under supplemental LED light
- Taxon
- tomatoSolanum lycopersicume0
- Treatment
- supplemental LED lighte0
- Outcome
- morphologye0
- Direction
- improvede0
- Comparator
- controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Both tomato and cucumber seedlings had increased growth rate and improved morphology when grown under the supplemental LED light compared to the control”
Claim · model-written summary
Cucumber seedlings increased growth rate under supplemental LED light
- Taxon
- cucumber
Cucumis sativuse0 - Treatment
- supplemental LED lighte0
- Outcome
- growth ratee0
- Direction
- increasede0
- Comparator
- controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Both tomato and cucumber seedlings had increased growth rate and improved morphology when grown under the supplemental LED light compared to the control”
Claim · model-written summary
Cucumber seedlings improved morphology under supplemental LED light
- Taxon
- cucumberCucumis sativuse0
- Treatment
- supplemental LED lighte0
- Outcome
- morphologye0
- Direction
- improvede0
- Comparator
- controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Both tomato and cucumber seedlings had increased growth rate and improved morphology when grown under the supplemental LED light compared to the control”
Claim · model-written summary
Tomato growth and morphology did not differ among B:R ratios under high DLI
- Taxon
- tomatoSolanum lycopersicume1
- Treatment
- different B:R ratiose1
- Outcome
- growth and morphological parameterse1
- Direction
- no_changeinferrede1
- Setting
- high DLI conditionse1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“However, no significant differences were observed for any growth and morphological parameters measured in this study between the different B:R ratios for both cucumber and tomato transplants under high DLI conditions”
Claim · model-written summary
Cucumber growth and morphology did not differ among B:R ratios under high DLI
- Taxon
- cucumberCucumis sativuse1
- Treatment
- different B:R ratiose1
- Outcome
- growth and morphological parameterse1
- Direction
- no_changeinferrede1
- Setting
- high DLI conditionse1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“However, no significant differences were observed for any growth and morphological parameters measured in this study between the different B:R ratios for both cucumber and tomato transplants under high DLI conditions”
Claim · model-written summary
Cucumber dry mass, leaf number and leaf area tended to decrease with increasing B:R ratio under low DLI
- Taxon
- CucumberCucumis sativuse2
- Treatment
- increasing B:R ratioe2
- Outcome
- dry mass, leaf number and leaf areae2
- Direction
- decreasee2
- Qualifier
- tendencye2
- Setting
- low DLI conditionse2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e2“Cucumber seedlings showed a tendency to decrease dry mass, leaf number and leaf area under low DLI conditions with increasing B:R ratio”
Claim · model-written summary
Tomato seedlings showed no differences among B:R ratios under low DLI
- Taxon
- TomatoSolanum lycopersicume3
- Treatment
- different B:R ratiose3
- Outcome
- differencese3
- Direction
- no_changeinferrede3
- Setting
- low DLI conditionse3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e3“Tomato seedlings did not show any differences between the different B:R ratios under low DLI conditions”
Claim · model-written summary
Cucumber shoot dry mass was greater under supplemental HPS light than under red LED
- Taxon
- CucumberCucumis sativuse4
- Treatment
- supplemental HPS lighte4
- Outcome
- shoot dry masse4
- Direction
- greatere4
- Comparator
- supplemental red LED lighte4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e4“Cucumber seedlings under supplemental HPS light had greater shoot dry mass than those under the supplemental red LED light”
Claim · model-written summary
Tomato shoot dry mass did not differ between HPS and red LED supplemental light
- Taxon
- TomatoSolanum lycopersicume5
- Treatment
- HPSe5
- Outcome
- shoot dry masse5
- Direction
- no_changeinferrede5
- Comparator
- red LEDe5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e5“Tomato shoot dry mass showed no differences between the HPS and red LED supplemental light treatments”
Claim · model-written summary
Cucumber shoot dry mass and net photosynthetic rate did not differ between pulsed and continuous LED lighting
- Taxon
- CucumberCucumis sativuse6
- Treatment
- supplemental LED pulsed lightinge6
- Outcome
- shoot dry mass and net photosynthetic ratee6
- Direction
- no_changeinferrede6
- Comparator
- supplemental LED continuous lightinge6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e6“Cucumber seedlings were also grown under supplemental LED pulsed lighting and supplemental LED continuous lighting. Cucumber seedlings showed no differences in shoot dry mass and net photosynthetic rate between the treatments”
Claim · model-written summary
Red LED is preferred for supplemental lighting of greenhouse vegetable seedlings
Verbatim
t0“Growth and development of greenhouse vegetable seedlings under supplemental LED lighting”
e7“these studies concluded that red LED is preferred for supplemental lighting”
Claim · model-written summary
Increasing blue light gives no benefit unless blue LED efficiency greatly exceeds red LED
Verbatim
t0“Growth and development of greenhouse vegetable seedlings under supplemental LED lighting”
e7“the increase of blue light does not offer any benefits unless the efficiency of blue LEDs largely exceeds the red LEDs”
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See all 226 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.