Abstract
Abstract The effect of varying phosphorus (P) supply on the growth, yield, leaf abnormalities, and nutrient composition was investigated for three lettuce cultivars (Chaparal, Wintercrisp, and Robinvale) in sand culture and soil. The leaf P content for optimum yields varied between 0.40 and 0.90% while higher than 0.90% P seemed to cause leaf abnormalities in Chaparal and Winter‐crisp. With high P supply, more calcium (Ca) was necessary to overcome the detrimental effect of P. In soil, maximum yields were obtained with a P supply level of 540 mg/kg P, while higher levels caused yield reductions. Soil analysis at the end of the experiment showed that a soil P content of 250 mg/kg P (Bray II) was associated with the best yield. When additional Ca was supplied to the soil, yield reduction due to high P supply was reduced. The leaf abnormalities which coincided with the high P supply were similar to those which have previously been described for auxin‐type herbicide damage on lettuce.
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Claims 9
Claim · model-written summary
Leaf P content for optimum lettuce yields ranged from 0.40 to 0.90%.
- Taxon
- lettuce
Lactuca sativat0 - Organ / stage
- leafe0
- Outcome
- leaf P content for optimum yieldse0
- Value
- 0.40 and 0.90%e0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The leaf P content for optimum yields varied between 0.40 and 0.90%”
t0“lettuce”
Claim · model-written summary
P above 0.90% appeared to cause leaf abnormalities in Chaparal.
- Taxon
- lettuceLactuca sativat0
- Material
- Chaparale0
- Organ / stage
- leafe0
- Outcome
- leaf abnormalitiese0
- Value
- 0.90%e0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“higher than 0.90% P seemed to cause leaf abnormalities in Chaparal and Winter‐crisp.”
t0“lettuce”
Claim · model-written summary
P above 0.90% appeared to cause leaf abnormalities in Winter-crisp.
- Taxon
- lettuceLactuca sativat0
- Material
- Winter‐crispe0
- Organ / stage
- leafe0
- Outcome
- leaf abnormalitiese0
- Value
- 0.90%e0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“higher than 0.90% P seemed to cause leaf abnormalities in Chaparal and Winter‐crisp.”
t0“lettuce”
Claim · model-written summary
Higher calcium supply was needed to counter the detrimental effect of high P.
- Taxon
- lettuceLactuca sativat0
- Treatment
- more calcium (Ca)e0
- Outcome
- detrimental effect of Pe0
- Direction
- overcomee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“With high P supply, more calcium (Ca) was necessary to overcome the detrimental effect of P.”
t0“lettuce”
Claim · model-written summary
In soil, a P supply of 540 mg/kg P gave maximum lettuce yields.
- Taxon
- lettuceLactuca sativat0
- Treatment
- P supply level of 540 mg/kg Pe0
- Outcome
- yieldse0
- Direction
- maximume0
- Value
- 540 mg/kg Pe0
- Comparator
- higher levelse0
- Setting
- soile0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In soil, maximum yields were obtained with a P supply level of 540 mg/kg P, while higher levels caused yield reductions.”
t0“lettuce”
Claim · model-written summary
P supply above 540 mg/kg P reduced lettuce yields.
- Taxon
- lettuceLactuca sativat0
- Treatment
- higher levelse0
- Outcome
- yielde0
- Direction
- reductionse0
- Comparator
- P supply level of 540 mg/kg Pe0
- Setting
- soile0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In soil, maximum yields were obtained with a P supply level of 540 mg/kg P, while higher levels caused yield reductions.”
t0“lettuce”
Claim · model-written summary
Soil P content of 250 mg/kg P was associated with best yield.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a soil P content of 250 mg/kg P (Bray II) was associated with the best yield.”
t0“lettuce”
Claim · model-written summary
Additional Ca reduced yield loss from high P supply.
- Taxon
- lettuceLactuca sativat0
- Treatment
- additional Cae0
- Outcome
- yield reduction due to high P supplye0
- Direction
- reducede0
- Setting
- soile0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“When additional Ca was supplied to the soil, yield reduction due to high P supply was reduced.”
t0“lettuce”
Claim · model-written summary
High-P leaf abnormalities resembled auxin-type herbicide damage.
- Taxon
- lettuceLactuca sativae0
- Organ / stage
- leafe0
- Outcome
- leaf abnormalitiese0
- Comparator
- auxin‐type herbicide damagee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The leaf abnormalities which coincided with the high P supply were similar to those which have previously been described for auxin‐type herbicide damage on lettuce.”
The same questions in other papers
calcium atom · yield · Lactuca sativa (garden lettuce)Results agree
5 papers in the same direction as this paper
- positive
- positive
- positive
2 papers more in this group
See all 6 papers →phosphorus · yield · Lactuca sativa (garden lettuce)Results differ
17 papers in the same direction as this paper · 2 in the opposite direction
- no effect
- negative
- positive
16 papers more in this group
See all 20 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.