Abstract
Plant density and atmospheric carbon dioxide level were manipulated to optimize productivity of cowpea [Vigna unguiculata (L.) Walp] for future use in a space-deployed Controlled Ecological Life Support System. Cowpea breeding line IT87D-941-1 was grown at plant densities of 3.6, 7.2, 10.7, or 14.3 plants m-2 in a growth chamber maintained at 400 (control) or 1200 (elevated) micromoles CO2 mol-1. Both green leaves and dried seeds were harvested as edible yield. Crop productivity was measured by edible yield rate (EYR), harvest index (HI), yield efficiency rate (YER), energy efficiency, and net photosynthesis (Pn). Increasing plant density within a canopy tended to increase EYR, but decreased HI and YER. Elevated CO2 also increased EYR, but decreased HI and YER as well. However, when the energy penalty for crop production was taken into consideration, cowpea crops grown under elevated CO2 were more productive than those grown at control CO2. Pn averaged 15 micromoles CO2 m-2 s-1 for cowpeas grown at 400 micromoles CO2 mol-1. Low Pn at the beginning and end of the cropping cycle indicated waste of high irradiance lighting during those times.
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Claims 7
Claim · model-written summary
Increasing plant density tended to increase edible yield rate.
Not reportedTaxonComparator
Verbatim
e0“Increasing plant density within a canopy tended to increase EYR, but decreased HI and YER.”
Claim · model-written summary
Increasing density decreased harvest index and yield efficiency rate.
Not reportedTaxonComparator
Verbatim
e0“Increasing plant density within a canopy tended to increase EYR, but decreased HI and YER.”
Claim · model-written summary
Elevated CO2 increased edible yield rate.
Not reportedTaxonComparator
Verbatim
e0“Elevated CO2 also increased EYR, but decreased HI and YER as well.”
Claim · model-written summary
Elevated CO2 decreased harvest index and yield efficiency rate.
Not reportedTaxonComparator
Verbatim
e0“Elevated CO2 also increased EYR, but decreased HI and YER as well.”
Claim · model-written summary
Accounting for energy penalty, elevated CO2 crops were more productive than controls.
- Taxon
- cowpea
Vigna unguiculatae0 - Treatment
- elevated CO2e0
- Outcome
- productivee0
- Direction
- more productivee0
- Comparator
- control CO2e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“cowpea crops grown under elevated CO2 were more productive than those grown at control CO2.”
Claim · model-written summary
Mean net photosynthesis under 400 micromoles CO2 mol-1 was 15 micromoles CO2 m-2 s-1.
- Taxon
- cowpeasVigna unguiculatae0
- Treatment
- 400 micromoles CO2 mol-1e0
- Outcome
- Pne0
- Value
- 15 micromoles CO2 m-2 s-1e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Pn averaged 15 micromoles CO2 m-2 s-1 for cowpeas grown at 400 micromoles CO2 mol-1.”
Claim · model-written summary
Low photosynthesis at the start and end suggested lighting energy waste.
- Organ / stage
- beginning and end of the cropping cyclee0
- Outcome
- Low Pne0
- Qualifier
- waste of high irradiance lightinge0
Not reportedTaxon
Verbatim
e0“Low Pn at the beginning and end of the cropping cycle indicated waste of high irradiance lighting during those times.”
The same questions in other papers
density · yield · Vigna unguiculata (cowpea)Positive and negative results
49 papers in the same direction as this paper · 13 in the opposite direction
- negative
- no effect
- negative
59 papers more in this group
See all 63 papers →co2 · yield · Vigna unguiculata (cowpea)Results agree
3 papers in the same direction as this paper
- positive
- positive
- positive
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.