Abstract
Acetylene reduction and nitrogen difference assays were used to evaluate effects of defoliation by soybean looper, Pseudoplusia includens (Walker), during reproductive growth stages on symbiotic nitrogen fixation by soybean, Glycine max (L.) Merrill. Defoliation (74-94%) of group IV ‘Clark’ caused 80-100% reduction of ethylene produced per gram nodule dry weight (nodule specific activity), regardless of whether defoliation occurred during bloom and pod development or during seed development. Defoliation (50-55%) of group VI cultivar ‘Lee’ from full bloom into pod development stages caused up to 69% reduction of nodule specific activity, whereas lower defoliation levels (32%) during seed development did not affect this parameter. The nitrogen difference assay did not identify reductions in the amount of nitrogen acquired from symbiotically fixed sources in response to defoliation except in I experiment when 55% defoliation of Lee occurred during a period from full bloom into early seed development. However, this assay was useful for determining the influence of N acquired from soil and fixed sources on plant N status. Up to 68% of the N in non defoliated nodulating isoline plants was acquired from fixed sources. Nitrogen deficiency symptoms (chlorosis) were evident by early seed development, indicating that soil N was becoming depleted by that growth stage. In general, when averaged across cultivars and years, greater amounts of N were acquired from fixed sources by the early seed development stage (54%) than by bloom and pod development stages (35%). Yield of Clark was reduced by 800-1,359 kg/ha (74-94% defoliation, full bloom through pod development) and by 750 kg/ha (94% defoliation, early seed development). Yield of Lee was reduced by 1,492 kg/ha (50% defoliation, full bloom through pod development) and by 971 kg11m (32% defoliation, early seed development).
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Claims 12
Claim · model-written summary
Defoliation of group IV Clark by 74-94% caused an 80-100% reduction of nodule specific activity, whether during bloom and pod development or during seed development.
- Taxon
- Soybean
Glycine maxt0 - Material
- Clarke1
- Organ / stage
- bloom and pod development or during seed developmente1
- Treatment
- Defoliation (74-94%)e1
- Interactor
- Soybean Looper
Chrysodeixis includenst0pest - Outcome
- nodule specific activitye1
- Direction
- reductione1
- Value
- 80-100%e1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Symbiotic Nitrogen Fixation and Yield of Soybean Following Defoliation by Soybean Looper”
e1“Defoliation (74-94%) of group IV ‘Clark’ caused 80-100% reduction of ethylene produced per gram nodule dry weight (nodule specific activity), regardless of whether defoliation occurred during bloom and pod development or during seed development”
Claim · model-written summary
Defoliation of group VI cultivar Lee by 50-55% from full bloom into pod development reduced nodule specific activity by up to 69%.
- Taxon
- SoybeanGlycine maxt0
- Material
- Leee2
- Organ / stage
- from full bloom into pod development stagese2
- Treatment
- Defoliation (50-55%)e2
- Interactor
- Soybean LooperChrysodeixis includenst0pest
- Outcome
- nodule specific activitye2
- Direction
- reductione2
- Value
- up to 69%e2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Symbiotic Nitrogen Fixation and Yield of Soybean Following Defoliation by Soybean Looper”
e2“Defoliation (50-55%) of group VI cultivar ‘Lee’ from full bloom into pod development stages caused up to 69% reduction of nodule specific activity, whereas lower defoliation levels (32%) during seed development did not affect this parameter”
Claim · model-written summary
Lower defoliation of Lee (32%) during seed development did not affect nodule specific activity.
- Taxon
- SoybeanGlycine maxt0
- Material
- Leee2
- Organ / stage
- seed developmente2
- Treatment
- lower defoliation levels (32%)e2
- Interactor
- Soybean LooperChrysodeixis includenst0pest
- Outcome
- nodule specific activitye2
- Direction
- did not affecte2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Symbiotic Nitrogen Fixation and Yield of Soybean Following Defoliation by Soybean Looper”
e2“Defoliation (50-55%) of group VI cultivar ‘Lee’ from full bloom into pod development stages caused up to 69% reduction of nodule specific activity, whereas lower defoliation levels (32%) during seed development did not affect this parameter”
Claim · model-written summary
The nitrogen difference assay did not detect reductions in nitrogen acquired from fixed sources in response to defoliation.
- Taxon
- SoybeanGlycine maxt0
- Treatment
- defoliatione3
- Interactor
- Soybean LooperChrysodeixis includenst0pest
- Outcome
- reductions in the amount of nitrogen acquired from symbiotically fixed sourcese3
- Direction
- did not identify reductionse3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Symbiotic Nitrogen Fixation and Yield of Soybean Following Defoliation by Soybean Looper”
e3“The nitrogen difference assay did not identify reductions in the amount of nitrogen acquired from symbiotically fixed sources in response to defoliation except in I experiment when 55% defoliation of Lee occurred during a period from full bloom into early seed development”
Claim · model-written summary
Defoliation of Lee by 55% from full bloom into early seed development reduced the amount of nitrogen acquired from fixed sources, as the exception to c4.
- Taxon
- SoybeanGlycine maxt0
- Material
- Leee3
- Organ / stage
- from full bloom into early seed developmente3
- Treatment
- 55% defoliatione3
- Interactor
- Soybean LooperChrysodeixis includenst0pest
- Outcome
- the amount of nitrogen acquired from symbiotically fixed sourcese3
- Direction
- reductionse3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Symbiotic Nitrogen Fixation and Yield of Soybean Following Defoliation by Soybean Looper”
e3“The nitrogen difference assay did not identify reductions in the amount of nitrogen acquired from symbiotically fixed sources in response to defoliation except in I experiment when 55% defoliation of Lee occurred during a period from full bloom into early seed development”
Claim · model-written summary
Up to 68% of the N in non-defoliated nodulating isoline plants was acquired from fixed sources.
- Taxon
- SoybeanGlycine maxt0
- Material
- nodulating isolinee4
- Interactor
- Soybean LooperChrysodeixis includenst0pest
- Outcome
- acquired from fixed sourcese4
- Value
- Up to 68%e4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Symbiotic Nitrogen Fixation and Yield of Soybean Following Defoliation by Soybean Looper”
e4“Up to 68% of the N in non defoliated nodulating isoline plants was acquired from fixed sources”
Claim · model-written summary
Nitrogen deficiency symptoms (chlorosis) were evident by early seed development, indicating depletion of soil N by that stage.
- Taxon
- SoybeanGlycine maxt0
- Organ / stage
- early seed developmente5
- Interactor
- Soybean LooperChrysodeixis includenst0pest
- Outcome
- Nitrogen deficiency symptoms (chlorosis)e5
- Qualifier
- indicating that soil N was becoming depletede5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Symbiotic Nitrogen Fixation and Yield of Soybean Following Defoliation by Soybean Looper”
e5“Nitrogen deficiency symptoms (chlorosis) were evident by early seed development, indicating that soil N was becoming depleted by that growth stage”
Claim · model-written summary
Averaged across cultivars and years, more N was acquired from fixed sources at early seed development (54%) than at bloom and pod development (35%).
- Taxon
- SoybeanGlycine maxt0
- Organ / stage
- early seed development stagee6
- Interactor
- Soybean LooperChrysodeixis includenst0pest
- Outcome
- amounts of N were acquired from fixed sourcese6
- Direction
- greatere6
- Value
- 54%e6
- Qualifier
- averaged across cultivars and yearse6
- Comparator
- bloom and pod development stagese6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Symbiotic Nitrogen Fixation and Yield of Soybean Following Defoliation by Soybean Looper”
e6“In general, when averaged across cultivars and years, greater amounts of N were acquired from fixed sources by the early seed development stage (54%) than by bloom and pod development stages (35%)”
Claim · model-written summary
Defoliation of Clark by 74-94% at full bloom through pod development reduced yield by 800-1,359 kg/ha.
- Taxon
- SoybeanGlycine maxt0
- Material
- Clarke7
- Organ / stage
- full bloom through pod developmente7
- Treatment
- 74-94% defoliatione7
- Interactor
- Soybean LooperChrysodeixis includenst0pest
- Outcome
- Yielde7
- Direction
- reducede7
- Value
- 800-1,359 kg/hae7
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Symbiotic Nitrogen Fixation and Yield of Soybean Following Defoliation by Soybean Looper”
e7“Yield of Clark was reduced by 800-1,359 kg/ha (74-94% defoliation, full bloom through pod development) and by 750 kg/ha (94% defoliation, early seed development)”
Claim · model-written summary
Defoliation of Clark by 94% at early seed development reduced yield by 750 kg/ha.
- Taxon
- SoybeanGlycine maxt0
- Material
- Clarke7
- Organ / stage
- early seed developmente7
- Treatment
- 94% defoliatione7
- Interactor
- Soybean LooperChrysodeixis includenst0pest
- Outcome
- Yielde7
- Direction
- reducede7
- Value
- 750 kg/hae7
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Symbiotic Nitrogen Fixation and Yield of Soybean Following Defoliation by Soybean Looper”
e7“Yield of Clark was reduced by 800-1,359 kg/ha (74-94% defoliation, full bloom through pod development) and by 750 kg/ha (94% defoliation, early seed development)”
Claim · model-written summary
Defoliation of Lee by 50% at full bloom through pod development reduced yield by 1,492 kg/ha.
- Taxon
- SoybeanGlycine maxt0
- Material
- Leee0
- Organ / stage
- full bloom through pod developmente0
- Treatment
- 50% defoliatione0
- Interactor
- Soybean LooperChrysodeixis includenst0pest
- Outcome
- Yielde0
- Direction
- reducede0
- Value
- 1,492 kg/hae0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Symbiotic Nitrogen Fixation and Yield of Soybean Following Defoliation by Soybean Looper”
e0“Yield of Lee was reduced by 1,492 kg/ha (50% defoliation, full bloom through pod development) and by 971 kg11m (32% defoliation, early seed development)”
Claim · model-written summary
Defoliation of Lee by 32% at early seed development reduced yield by 971 kg/ha.
- Taxon
- SoybeanGlycine maxt0
- Material
- Leee0
- Organ / stage
- early seed developmente0
- Treatment
- 32% defoliatione0
- Interactor
- Soybean LooperChrysodeixis includenst0pest
- Outcome
- Yielde0
- Direction
- reducede0
- Value
- 971 kg11me0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Symbiotic Nitrogen Fixation and Yield of Soybean Following Defoliation by Soybean Looper”
e0“Yield of Lee was reduced by 1,492 kg/ha (50% defoliation, full bloom through pod development) and by 971 kg11m (32% defoliation, early seed development)”
The same questions in other papers
pruning · Chrysodeixis includens · Glycine max (soybean)Positive and negative results
4 papers in the same direction as this paper · 2 in the opposite direction
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- positive
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See all 7 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.