Abstract
Abstract Atmospheric carbon dioxide and irradiance are important factors affecting growth and yield of plants. Due to the wide variation in irradiance in natural plant stands and the reportedly increasing carbon dioxide concentration in the global atmosphere, it is essential to study the interacting effects of these factors on the growth and production of crop plants. Growth analysis techniques were used to study the interaction of atmospheric CO 2 concentration (350 and 675 µl/l) and photosynthetic photon flux density (PPFD) (600 and 1200 µEM −2 s− 1 )on four species (including both seed and root crops) grown in controlled environment chambers of the Duke University Phytotron. The plants were soybean ( Glycine max L. Merr.), radish ( Raphanus sativus L.), sugarbeet ( Beta vulgaris L.), and corn ( Zea mays L.). Total dry matter production increased in all species of plants and at all growth stages with both increased CO 2 concentration and PPFD levels, and the maximum dry matter was produced at the highest combined levels of CO 2 and PPFD. The dry weight increase varied between the different species and between plant parts within a species. High levels of CO 2 and PPFD caused a greater increase in net assimilation rate in the plants during early growth stages than in later stages because the first two or three young, rapidly growing leaves were very efficient photosynthetic organs. A high CO 2 or PPFD level resulted in decreasing leaf area ratios with increasing plant age for all the species due to a rapid increase in stem and root growth later in fruit production, and to a decreasing specific leaf area. Corn, having the C 4 pathway of photosynthesis, showed less response to increased CO 2 and PPFD than the three C 3 species. Increasing the atmospheric CO 2 concentration from 350 to 675 µl/liter at low and high PPFD levels produced dry matter increases of 72.7 and 76.4%, respectively, in soybean, and 18.9 and 18.6%, respectively, in corn at 50 days after planting. None of the species tested were light saturated at levels available in the standard fluorescent and incandescent lighting as is shown by the increased growth when higher PPFD levels were obtained with a combination of multivapor and sodium lamps.
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Claims 10
Claim · model-written summary
Higher CO2 and light increased dry matter at all growth stages in all four crops.
- Taxon
- soybean
Glycine maxe1 - Treatment
- increased CO 2 concentration and PPFD levelse0
- Outcome
- Total dry matter productione0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“soybean ( Glycine max L. Merr.), radish ( Raphanus sativus L.), sugarbeet ( Beta vulgaris L.), and corn ( Zea mays L.)”
e0“Total dry matter production increased in all species of plants and at all growth stages with both increased CO 2 concentration and PPFD levels, and the maximum dry matter was produced at the highest combined levels of CO 2 and PPFD.”
Claim · model-written summary
Highest combined CO2 and light gave maximum dry matter.
- Taxon
- corn
Zea mays subsp. mayse1 - Treatment
- highest combined levels of CO 2 and PPFDe0
- Outcome
- dry mattere0
- Direction
- maximume0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“soybean ( Glycine max L. Merr.), radish ( Raphanus sativus L.), sugarbeet ( Beta vulgaris L.), and corn ( Zea mays L.)”
e0“Total dry matter production increased in all species of plants and at all growth stages with both increased CO 2 concentration and PPFD levels, and the maximum dry matter was produced at the highest combined levels of CO 2 and PPFD.”
Claim · model-written summary
High CO2 and light increased early net assimilation more than at later stages.
- Taxon
- soybeanGlycine maxe1
- Organ / stage
- early growth stagese0
- Treatment
- High levels of CO 2 and PPFDe0
- Outcome
- net assimilation ratee0
- Direction
- greater increasee0
- Comparator
- later stagese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“soybean ( Glycine max L. Merr.), radish ( Raphanus sativus L.), sugarbeet ( Beta vulgaris L.), and corn ( Zea mays L.)”
e0“High levels of CO 2 and PPFD caused a greater increase in net assimilation rate in the plants during early growth stages than in later stages because the first two or three young, rapidly growing leaves were very efficient photosynthetic organs.”
Claim · model-written summary
High CO2 or light reduced leaf area ratio as plants aged.
- Taxon
- cornZea mays subsp. mayse1
- Treatment
- high CO 2 or PPFD levele0
- Outcome
- leaf area ratiose0
- Direction
- decreasinge0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“soybean ( Glycine max L. Merr.), radish ( Raphanus sativus L.), sugarbeet ( Beta vulgaris L.), and corn ( Zea mays L.)”
e0“A high CO 2 or PPFD level resulted in decreasing leaf area ratios with increasing plant age for all the species due to a rapid increase in stem and root growth later in fruit production, and to a decreasing specific leaf area.”
Claim · model-written summary
Corn responded less to higher CO2 and light than C3 crops.
- Taxon
- cornZea mays subsp. mayse1
- Treatment
- increased CO 2 and PPFDe0
- Outcome
- responsee0
- Direction
- lesse0
- Comparator
- three C 3 speciese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“soybean ( Glycine max L. Merr.), radish ( Raphanus sativus L.), sugarbeet ( Beta vulgaris L.), and corn ( Zea mays L.)”
e0“Corn, having the C 4 pathway of photosynthesis, showed less response to increased CO 2 and PPFD than the three C 3 species.”
Claim · model-written summary
At low light, increased CO2 raised soybean dry matter by 72.7%.
- Taxon
- soybeanGlycine maxe1
- Treatment
- 350 to 675 µl/litere0
- Outcome
- dry mattere0
- Direction
- increasese0
- Value
- 72.7e0
- Qualifier
- lowe0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“soybean ( Glycine max L. Merr.), radish ( Raphanus sativus L.), sugarbeet ( Beta vulgaris L.), and corn ( Zea mays L.)”
e0“Increasing the atmospheric CO 2 concentration from 350 to 675 µl/liter at low and high PPFD levels produced dry matter increases of 72.7 and 76.4%, respectively, in soybean, and 18.9 and 18.6%, respectively, in corn at 50 days after planting.”
Claim · model-written summary
At high light, increased CO2 raised soybean dry matter by 76.4%.
- Taxon
- soybeanGlycine maxe1
- Treatment
- 350 to 675 µl/litere0
- Outcome
- dry mattere0
- Direction
- increasese0
- Value
- 76.4%e0
- Qualifier
- high PPFD levelse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“soybean ( Glycine max L. Merr.), radish ( Raphanus sativus L.), sugarbeet ( Beta vulgaris L.), and corn ( Zea mays L.)”
e0“Increasing the atmospheric CO 2 concentration from 350 to 675 µl/liter at low and high PPFD levels produced dry matter increases of 72.7 and 76.4%, respectively, in soybean, and 18.9 and 18.6%, respectively, in corn at 50 days after planting.”
Claim · model-written summary
At low light, increased CO2 raised corn dry matter by 18.9%.
- Taxon
- cornZea mays subsp. mayse1
- Treatment
- 350 to 675 µl/litere0
- Outcome
- dry mattere0
- Direction
- increasese0
- Value
- 18.9e0
- Qualifier
- lowe0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“soybean ( Glycine max L. Merr.), radish ( Raphanus sativus L.), sugarbeet ( Beta vulgaris L.), and corn ( Zea mays L.)”
e0“Increasing the atmospheric CO 2 concentration from 350 to 675 µl/liter at low and high PPFD levels produced dry matter increases of 72.7 and 76.4%, respectively, in soybean, and 18.9 and 18.6%, respectively, in corn at 50 days after planting.”
Claim · model-written summary
At high light, increased CO2 raised corn dry matter by 18.6%.
- Taxon
- cornZea mays subsp. mayse1
- Treatment
- 350 to 675 µl/litere0
- Outcome
- dry mattere0
- Direction
- increasese0
- Value
- 18.6%e0
- Qualifier
- high PPFD levelse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“soybean ( Glycine max L. Merr.), radish ( Raphanus sativus L.), sugarbeet ( Beta vulgaris L.), and corn ( Zea mays L.)”
e0“Increasing the atmospheric CO 2 concentration from 350 to 675 µl/liter at low and high PPFD levels produced dry matter increases of 72.7 and 76.4%, respectively, in soybean, and 18.9 and 18.6%, respectively, in corn at 50 days after planting.”
Claim · model-written summary
Higher light increased growth in all four species, indicating none was light saturated.
- Taxon
- cornZea mays subsp. mayse1
- Treatment
- higher PPFD levelse0
- Outcome
- growthe0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“soybean ( Glycine max L. Merr.), radish ( Raphanus sativus L.), sugarbeet ( Beta vulgaris L.), and corn ( Zea mays L.)”
e0“None of the species tested were light saturated at levels available in the standard fluorescent and incandescent lighting as is shown by the increased growth when higher PPFD levels were obtained with a combination of multivapor and sodium lamps.”
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See all 101 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.