Abstract
The productivity of lettuce in a combination of high light, high temperature, and elevated CO2 has not been commonly studied because rapid growth usually causes a calcium deficiency in meristems called tipburn, which greatly reduces quality and marketability. We eliminated tipburn by blowing air directly onto the meristem, which allowed us to increase the photosynthetic photon flux (PPF) to 1000 micromoles m-2 s-1 (57.6 mol m-2 d-1); two to three times higher than normally used for lettuce. Eliminating tipburn doubled edible yield at the highest PPF level. In addition to high PPF, CO2 was elevated to 1200 micromoles m-2 mol-1, which increased the temperature optimum from 25 to 30 degrees C. The higher temperature increased leaf expansion rate, which improved radiation capture and more than doubled yield. Photosynthetic efficiency, measured as canopy quantum yield in a whole-plant gas exchange system, steadily increased up to the highest temperature of 32 degrees C in high CO2. The highest productivity was 19 g m-2 d-1 of dry biomass (380 g d-1 fresh mass) averaged over the 23 days the plants received light. Without the limitation of tipburn, the combination of high PPF, high temperature, and elevated CO2 resulted in a 4-fold increase in growth rate over productivity in conventional environments.
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Claims 9
Claim · model-written summary
Blowing air onto the meristem eliminated tipburn in lettuce.
- Taxon
- Lettuce
Lactuca sativat0 - Treatment
- blowing air directly onto the meristeme0
- Outcome
- tipburne0
- Direction
- eliminatede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Exploring the Limits of Crop Productivity: Beyond the Limits of Tipburn in Lettuce”
e0“We eliminated tipburn by blowing air directly onto the meristem”
Claim · model-written summary
Eliminating tipburn doubled lettuce edible yield at the highest PPF level.
- Taxon
- LettuceLactuca sativat0
- Treatment
- Eliminating tipburne1
- Outcome
- edible yielde1
- Direction
- doublede1
- Qualifier
- at the highest PPF levele1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Exploring the Limits of Crop Productivity: Beyond the Limits of Tipburn in Lettuce”
e1“Eliminating tipburn doubled edible yield at the highest PPF level”
Claim · model-written summary
The higher temperature increased lettuce leaf expansion rate.
- Taxon
- LettuceLactuca sativat0
- Treatment
- higher temperaturee2
- Outcome
- leaf expansion ratee2
- Direction
- increasede2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Exploring the Limits of Crop Productivity: Beyond the Limits of Tipburn in Lettuce”
e2“The higher temperature increased leaf expansion rate, which improved radiation capture and more than doubled yield”
Claim · model-written summary
The higher temperature improved radiation capture in lettuce.
- Taxon
- LettuceLactuca sativat0
- Treatment
- higher temperaturee2
- Outcome
- radiation capturee2
- Direction
- improvede2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Exploring the Limits of Crop Productivity: Beyond the Limits of Tipburn in Lettuce”
e2“The higher temperature increased leaf expansion rate, which improved radiation capture and more than doubled yield”
Claim · model-written summary
The higher temperature more than doubled lettuce yield.
- Taxon
- LettuceLactuca sativat0
- Treatment
- higher temperaturee2
- Outcome
- yielde2
- Direction
- more than doublede2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Exploring the Limits of Crop Productivity: Beyond the Limits of Tipburn in Lettuce”
e2“The higher temperature increased leaf expansion rate, which improved radiation capture and more than doubled yield”
Claim · model-written summary
Photosynthetic efficiency of lettuce steadily increased up to 32 degrees C in high CO2.
- Taxon
- LettuceLactuca sativat0
- Treatment
- the highest temperature of 32 degrees Ce3
- Outcome
- Photosynthetic efficiencye3
- Direction
- steadily increasede3
- Setting
- high CO2e3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Exploring the Limits of Crop Productivity: Beyond the Limits of Tipburn in Lettuce”
e3“Photosynthetic efficiency, measured as canopy quantum yield in a whole-plant gas exchange system, steadily increased up to the highest temperature of 32 degrees C in high CO2”
Claim · model-written summary
The highest lettuce productivity was 19 g m-2 d-1 of dry biomass averaged over the light period.
- Taxon
- LettuceLactuca sativat0
- Outcome
- productivitye4
- Value
- 19 g m-2 d-1e4
- Qualifier
- averaged over the 23 days the plants received lighte4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Exploring the Limits of Crop Productivity: Beyond the Limits of Tipburn in Lettuce”
e4“The highest productivity was 19 g m-2 d-1 of dry biomass (380 g d-1 fresh mass) averaged over the 23 days the plants received light”
Claim · model-written summary
Elevated CO2 increased the temperature optimum of lettuce from 25 to 30 degrees C.
- Taxon
- LettuceLactuca sativat0
- Treatment
- CO2 was elevated to 1200 micromoles m-2 mol-1e5
- Outcome
- temperature optimume5
- Direction
- increasede5
- Value
- from 25 to 30 degrees Ce5
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Exploring the Limits of Crop Productivity: Beyond the Limits of Tipburn in Lettuce”
e5“CO2 was elevated to 1200 micromoles m-2 mol-1, which increased the temperature optimum from 25 to 30 degrees C”
Claim · model-written summary
Combined high PPF, high temperature and elevated CO2 without tipburn gave a 4-fold increase in lettuce growth rate over conventional environments.
- Taxon
- LettuceLactuca sativat0
- Treatment
- the combination of high PPF, high temperature, and elevated CO2e6
- Outcome
- growth ratee6
- Direction
- increasee6
- Value
- 4-folde6
- Comparator
- conventional environmentse6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Exploring the Limits of Crop Productivity: Beyond the Limits of Tipburn in Lettuce”
e6“Without the limitation of tipburn, the combination of high PPF, high temperature, and elevated CO2 resulted in a 4-fold increase in growth rate over productivity in conventional environments”
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