Abstract
Lowering nitrate nitrogen (NO³ -N) concentration in vegetables is desirable bccause of possible adverse health effects of high dietary nitratc intake. The effects of crop variety and cultural methods on NO³ -N content in lettuce and endive grown during winter in greenhouses in southern New England were investigated. "Green Ice" lettuce had 20-39% less NO³ -N than "Diamante," while "Winter Density," "Jeanette," "Cantille," "Sabrina," and "Vicki" had intermediate levels. "Red Salad Bowl" lettuce and the endives "Salad King" and "Nuvol" harvested in March had 52-68% less NO³ -N than the same cultivars harvested in mid-November. "Red Salad Bowl" had slightly more NO³ -N than "Green Ice" in November, but had 38% less than "Green Ice" in March. NO³ -N concentration in greenhouse-grown lettuce was directly related to the availability of inorganic nitrogen. Hydroponically grown lettuce had significantly higher NO³ -N levels than soil-grown lettuce. Transferring hydroponic lettuce to a nutrient solution containing 43% of the normal amount of N several weeks prior to harvest affected neither tissue NO³ -N nor yield. However, lifting soil-grown lettuce and setting its roots in water 40 hours prior to harvest resulted in a 19% decrease in NO³ -N.
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Claims 11
Claim · model-written summary
Green Ice lettuce had 20-39% less nitrate nitrogen than Diamante.
- Taxon
- lettuce
Lactuca sativae0 - Material
- Green Icee0
- Outcome
- NO³ -Ne0
- Direction
- lesse0
- Value
- 20-39%e0
- Comparator
- Diamantee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“"Green Ice" lettuce had 20-39% less NO³ -N than "Diamante,"”
Claim · model-written summary
Winter Density, Jeanette, Cantille, Sabrina, and Vicki had intermediate nitrate levels.
- Taxon
- lettuceLactuca sativae1
- Outcome
- intermediate levelse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“"Winter Density," "Jeanette," "Cantille," "Sabrina," and "Vicki" had intermediate levels”
e1“"Green Ice" lettuce had 20-39% less NO³ -N than "Diamante,"”
Claim · model-written summary
March-harvested Red Salad Bowl lettuce had 52-68% less nitrate than in mid-November.
- Taxon
- lettuceLactuca sativae0
- Material
- Red Salad Bowle0
- Treatment
- harvested in Marche0
- Outcome
- NO³ -Ne0
- Direction
- lesse0
- Value
- 52-68%e0
- Comparator
- harvested in mid-Novembere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“"Red Salad Bowl" lettuce and the endives "Salad King" and "Nuvol" harvested in March had 52-68% less NO³ -N than the same cultivars harvested in mid-November”
Claim · model-written summary
March-harvested Salad King and Nuvol endives had 52-68% less nitrate than in mid-November.
- Taxon
- endives
.jpg?width=60)
Cichorium endiviae0 - Treatment
- harvested in Marche0
- Outcome
- NO³ -Ne0
- Direction
- lesse0
- Value
- 52-68%e0
- Comparator
- harvested in mid-Novembere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e0“the endives "Salad King" and "Nuvol" harvested in March had 52-68% less NO³ -N than the same cultivars harvested in mid-November”
Claim · model-written summary
Red Salad Bowl had slightly more nitrate than Green Ice in November.
- Taxon
- LettuceLactuca sativat0
- Material
- Red Salad Bowle0
- Outcome
- NO³ -Ne0
- Direction
- moree0
- Comparator
- Green Icee0
- Setting
- Novembere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Lettuce”
e0“"Red Salad Bowl" had slightly more NO³ -N than "Green Ice" in November”
Claim · model-written summary
Red Salad Bowl had 38% less nitrate than Green Ice in March.
- Taxon
- LettuceLactuca sativat0
- Material
- Red Salad Bowle0
- Outcome
- NO³ -Ne0
- Direction
- lesse0
- Value
- 38%e0
- Comparator
- Green Icee0
- Setting
- Marche0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Lettuce”
e0“"Red Salad Bowl" had slightly more NO³ -N than "Green Ice" in November, but had 38% less than "Green Ice" in March”
Claim · model-written summary
Lettuce nitrate concentration was directly related to inorganic nitrogen availability.
- Taxon
- lettuceLactuca sativae0
- Compound
- inorganic nitrogene0
- Outcome
- NO³ -N concentratione0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“NO³ -N concentration in greenhouse-grown lettuce was directly related to the availability of inorganic nitrogen”
Claim · model-written summary
Hydroponic lettuce had significantly higher nitrate than soil-grown lettuce.
- Taxon
- lettuceLactuca sativae0
- Material
- Hydroponically grown lettucee0
- Outcome
- NO³ -N levelse0
- Direction
- highere0
- Comparator
- soil-grown lettucee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Hydroponically grown lettuce had significantly higher NO³ -N levels than soil-grown lettuce”
Claim · model-written summary
Reducing hydroponic nutrient solution nitrogen to 43% did not affect tissue nitrate.
- Taxon
- lettuceLactuca sativae0
- Treatment
- nutrient solution containing 43% of the normal amount of Ne0
- Outcome
- tissue NO³ -Ne0
- Direction
- affected neithere0
- Comparator
- normal amount of Ne0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Transferring hydroponic lettuce to a nutrient solution containing 43% of the normal amount of N several weeks prior to harvest affected neither tissue NO³ -N nor yield”
Claim · model-written summary
Reducing hydroponic nutrient solution nitrogen to 43% did not affect yield.
- Taxon
- lettuceLactuca sativae0
- Treatment
- nutrient solution containing 43% of the normal amount of Ne0
- Outcome
- yielde0
- Direction
- affected neithere0
- Comparator
- normal amount of Ne0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Transferring hydroponic lettuce to a nutrient solution containing 43% of the normal amount of N several weeks prior to harvest affected neither tissue NO³ -N nor yield”
Claim · model-written summary
Putting soil-grown lettuce roots in water 40 hours before harvest decreased nitrate by 19%.
- Taxon
- lettuceLactuca sativae0
- Treatment
- setting its roots in water 40 hours prior to harveste0
- Outcome
- NO³ -Ne0
- Direction
- decreasee0
- Value
- 19%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“lifting soil-grown lettuce and setting its roots in water 40 hours prior to harvest resulted in a 19% decrease in NO³ -N”
The same questions in other papers
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See all 249 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.