Abstract
If low night temperatures can be combined with high day temperatures, providing optimal growth conditions for plants, a significant energy saving can be achieved in greenhouses. Lowering the night temperature from 18°C to 10°C-11°C for 8 h had no negative effect on the CO2 exchange rate (CER) during the following light period in tomato. This was found both in plants grown in artificial light only or in combination with daylight. Allowing the temperature to increase from 20°C to about 40°C, in parallel with an increasing solar photon flux density (PFD) from 0 up to about 800 μmol·m-2·s-1 in the greenhouse during summer, progressively increased CER when the CO2 concentration was maintained at 900 μmol·mol-1. At 400 μmol·mol-1 CO2, maximum CER was reached at about 600 μmol·m-2·s-1 PFD combined with a temperature of 32°C, and leveled out with a further increase in PFD and temperature. Maximum CER at high CO2 concentration was around 100% higher than at low CO2 level. Under early autumn conditions, CER increased up to about 500 μmol·m-2·s-1 PFD/32°C at low CO2 and up to about 600 μmol·m-2·s-1 PFD/35°C at high CO2. An elevated CO2 level doubled the CER in this experiment as well. Measurements of chlorophyll fluorescence showed no effect of low night temperature, high day temperature or CO2 concentration on the quantum yield of photosynthesis, indicating that no treatment negatively affected the efficiency of the photosynthetic apparatus. The results showed that low night temperatures may be combined with very high day temperatures without any loss of daily photosynthesis particularly in a CO2 enriched atmosphere. If this can be combined with normal plant development and no negative effects on the yield, significant energy savings can be achieved in greenhouses.
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Claims 11
Claim · model-written summary
Lowering night temperature to 10°C-11°C did not negatively affect subsequent tomato CO2 exchange rate.
- Taxon
- tomato
Solanum lycopersicume0 - Treatment
- 10°C-11°C for 8 he0
- Outcome
- CO2 exchange rate (CER)e0
- Direction
- no negative effecte0
- Comparator
- 18°Ce0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Lowering the night temperature from 18°C to 10°C-11°C for 8 h had no negative effect on the CO2 exchange rate (CER) during the following light period in tomato”
Claim · model-written summary
Under high CO2, rising day temperature and photon flux progressively increased tomato CER.
- Taxon
- TomatoSolanum lycopersicumt0
- Treatment
- temperature to increase from 20°C to about 40°Ce0
- Outcome
- CERe0
- Direction
- increasede0
- Qualifier
- CO2 concentration was maintained at 900 μmol·mol-1e0
- Setting
- greenhousee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Allowing the temperature to increase from 20°C to about 40°C, in parallel with an increasing solar photon flux density (PFD) from 0 up to about 800 μmol·m-2·s-1 in the greenhouse during summer, progressively increased CER when the CO2 concentration was maintained at 900 μmol·mol-1”
t0“Tomato”
Claim · model-written summary
At low CO2, tomato CER reached its maximum near 600 μmol·m-2·s-1 PFD and 32°C, then leveled out.
- Taxon
- TomatoSolanum lycopersicumt0
- Outcome
- CERe0
- Direction
- maximume0
- Value
- 600 μmol·m-2·s-1e0
- Qualifier
- At 400 μmol·mol-1 CO2e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“At 400 μmol·mol-1 CO2, maximum CER was reached at about 600 μmol·m-2·s-1 PFD combined with a temperature of 32°C, and leveled out with a further increase in PFD and temperature”
t0“Tomato”
Claim · model-written summary
Maximum tomato CER at high CO2 was around 100% higher than at low CO2.
- Taxon
- TomatoSolanum lycopersicumt0
- Treatment
- high CO2 concentratione0
- Outcome
- Maximum CERe0
- Direction
- highere0
- Value
- around 100%e0
- Comparator
- low CO2 levele0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Maximum CER at high CO2 concentration was around 100% higher than at low CO2 level”
t0“Tomato”
Claim · model-written summary
In early autumn at low CO2, tomato CER increased up to about 500 μmol·m-2·s-1 PFD and 32°C.
- Taxon
- TomatoSolanum lycopersicumt0
- Outcome
- CERe0
- Direction
- increasede0
- Value
- about 500 μmol·m-2·s-1 PFD/32°Ce0
- Qualifier
- low CO2e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Under early autumn conditions, CER increased up to about 500 μmol·m-2·s-1 PFD/32°C at low CO2”
t0“Tomato”
Claim · model-written summary
In early autumn at high CO2, tomato CER increased up to about 600 μmol·m-2·s-1 PFD and 35°C.
- Taxon
- TomatoSolanum lycopersicumt0
- Outcome
- CERe1
- Direction
- increasede1
- Value
- about 600 μmol·m-2·s-1 PFD/35°Ce0
- Qualifier
- high CO2e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“and up to about 600 μmol·m-2·s-1 PFD/35°C at high CO2”
t0“Tomato”
e1“Under early autumn conditions, CER increased up to about 500 μmol·m-2·s-1 PFD/32°C at low CO2 and up to about 600 μmol·m-2·s-1 PFD/35°C at high CO2”
Claim · model-written summary
Elevated CO2 doubled tomato CER in the early autumn experiment.
- Taxon
- TomatoSolanum lycopersicumt0
- Treatment
- elevated CO2 levele0
- Outcome
- CERe0
- Direction
- doublede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“An elevated CO2 level doubled the CER in this experiment as well”
t0“Tomato”
Claim · model-written summary
Low night temperature did not affect the quantum yield of photosynthesis in tomato.
- Taxon
- TomatoSolanum lycopersicumt0
- Treatment
- low night temperaturee0
- Outcome
- quantum yield of photosynthesise0
- Direction
- no effecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Measurements of chlorophyll fluorescence showed no effect of low night temperature, high day temperature or CO2 concentration on the quantum yield of photosynthesis”
t0“Tomato”
Claim · model-written summary
High day temperature did not affect the quantum yield of photosynthesis in tomato.
- Taxon
- TomatoSolanum lycopersicumt0
- Treatment
- high day temperaturee0
- Outcome
- quantum yield of photosynthesise0
- Direction
- no effecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Measurements of chlorophyll fluorescence showed no effect of low night temperature, high day temperature or CO2 concentration on the quantum yield of photosynthesis”
t0“Tomato”
Claim · model-written summary
CO2 concentration did not affect the quantum yield of photosynthesis in tomato.
- Taxon
- TomatoSolanum lycopersicumt0
- Treatment
- CO2 concentratione0
- Outcome
- quantum yield of photosynthesise0
- Direction
- no effecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Measurements of chlorophyll fluorescence showed no effect of low night temperature, high day temperature or CO2 concentration on the quantum yield of photosynthesis”
t0“Tomato”
Claim · model-written summary
The authors conclude that low nights can be paired with very high days without loss of daily tomato photosynthesis, especially with CO2 enrichment.
- Taxon
- TomatoSolanum lycopersicumt0
- Outcome
- low night temperatures may be combined with very high day temperatures without any loss of daily photosynthesise0
- Qualifier
- particularly in a CO2 enriched atmospheree0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“low night temperatures may be combined with very high day temperatures without any loss of daily photosynthesis particularly in a CO2 enriched atmosphere”
t0“Tomato”
The same questions in other papers
co2 · physiology: photosynthesis · Solanum lycopersicum (tomato)Results differ
7 papers in the same direction as this paper · 31 in the opposite direction
- positive
- positive
- positive
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