Abstract
1. Nitrogen (N) application compensated for shoot removal-induced yield loss but reduced N use efficiency (NUE), while simultaneously enhancing pod growth and carbon metabolism in dual-purpose rapeseed. 2. A higher amino acid/soluble sugar ratio in pod walls promoted seed protein accumulation but decreased oil content. 3. The seed oil yield under SR with 270 kg N ha⁻ 1 was nearly equal to that under CK with 90 kg N ha⁻ 1 . As a multifunctional crop, rapeseed provides vegetables by picking shoots. Shoot removal reduced yield, while nitrogen (N) application results in efficiency gains. However, the effect of N rate on pod growth, N use efficiency (NUE) and seed yield after shoot removal is unclear. A 2-year field experiment was set with four N rates (0 [N0], 90 [N1], 180 [N2], and 270 [N3] kg ha −1 ) and two shoot treatments (no shoot removal [CK], shoot removal [SR]). Results showed the shoot removal decreased population biomass (PB) at maturity across all N levels. Conversely, N application increased the PB after shoot removal and elevated soluble sugar and protein in shoots. Shoot removal increased the seeds per pod (13.5-26.9%), reduced the pods per plant (33.1-45.8%) and population seed yield (19.5-38.4%). N application effectively increased the yield related index, and led to an increase in population seed yield by 187.2 - 465.0% in the CK group, and by 185.6 - 430.7% in the SR group. Moreover, the seed yield reached its maximum under the N3 in both groups. The leaf N content per area (N a ) and net photosynthetic rate ( P n ) were increased, but leaf photosynthetic N use efficiency (PNUE) were decreased at 20 days after shoot removal, which lead to a significant decrease in N use efficiency(NUE). N supply increased the plant organ N content and PB, but decreased the NUE at maturity stage. P n of the pod wall at 25 days after flowering was elevated due to its optimized chloroplasts ultrastructure and increased rubisco and sucrose synthase activities under shoot removal and more N. However, the greater amino acid/soluble sugar ratio (A/S) of the pod wall significantly increased the seed protein content and decreased the oil content. Though the oil yield was reduced by 63.8-71.0% under SR×N3 treatment compared with CK×N3, it was comparable to that of CK with 90 kg N ha −1 treatment. The results indicated that N applying improves the carbon metabolism of the pod wall and alleviates yield reduction after shoot removal but reduces NUE and seed oil content of rapeseed. The findings guide the balancing of rapeseed's vegetable and oil production, and optimize N fertilization for sustainable, efficient rapeseed farming.
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Claims 18
Claim · model-written summary
Shoot removal lowered mature population biomass at every nitrogen level.
Verbatim
e0“shoot removal decreased population biomass (PB) at maturity across all N levels”
t0“rapeseed”
Claim · model-written summary
Nitrogen increased population biomass after shoot removal.
- Taxon
- rapeseedt0
- Treatment
- N applicatione0
- Outcome
- PBe0
- Direction
- increasede0
- Qualifier
- after shoot removale0
Not reportedComparator
Verbatim
e0“N application increased the PB after shoot removal”
t0“rapeseed”
Claim · model-written summary
Nitrogen elevated soluble sugar and protein in shoots after shoot removal.
Not reportedTreatmentComparator
Verbatim
e0“elevated soluble sugar and protein in shoots”
t0“rapeseed”
Claim · model-written summary
Shoot removal increased seeds per pod by 13.5-26.9%.
Not reportedComparator
Verbatim
e0“Shoot removal increased the seeds per pod (13.5-26.9%)”
t0“rapeseed”
Claim · model-written summary
Shoot removal reduced pods per plant by 33.1-45.8%.
Not reportedTreatmentComparator
Verbatim
e0“reduced the pods per plant (33.1-45.8%)”
t0“rapeseed”
Claim · model-written summary
Shoot removal reduced population seed yield by 19.5-38.4%.
Not reportedTreatmentComparator
Verbatim
e0“population seed yield (19.5-38.4%)”
t0“rapeseed”
Claim · model-written summary
Nitrogen raised population seed yield in the no-removal group by 187.2 - 465.0%.
- Taxon
- rapeseedt0
- Outcome
- population seed yielde0
- Direction
- increasee0
- Value
- 187.2 - 465.0%e0
- Qualifier
- CK groupe0
Not reportedTreatmentComparator
Verbatim
e0“increase in population seed yield by 187.2 - 465.0% in the CK group”
t0“rapeseed”
Claim · model-written summary
Nitrogen raised population seed yield in the shoot-removal group by 185.6 - 430.7%.
- Taxon
- rapeseedt0
- Outcome
- population seed yielde0
- Direction
- increaseinferrede0
- Value
- 185.6 - 430.7%e0
- Qualifier
- SR groupe0
Not reportedTreatmentComparator
Verbatim
e0“population seed yield by 187.2 - 465.0% in the CK group, and by 185.6 - 430.7% in the SR group”
t0“rapeseed”
Claim · model-written summary
Seed yield was highest at the N3 nitrogen rate in both shoot treatments.
Verbatim
e0“seed yield reached its maximum under the N3 in both groups”
t0“rapeseed”
Claim · model-written summary
Leaf nitrogen content per area and net photosynthetic rate increased 20 days after shoot removal.
- Taxon
- rapeseedt0
- Outcome
- leaf N content per area (N a ) and net photosynthetic rate ( P n )e0
- Direction
- increasede0
Not reportedTreatmentComparator
Verbatim
e0“leaf N content per area (N a ) and net photosynthetic rate ( P n ) were increased”
t0“rapeseed”
Claim · model-written summary
Leaf photosynthetic nitrogen use efficiency fell 20 days after shoot removal.
- Taxon
- rapeseedt0
- Treatment
- shoot removale0
- Outcome
- leaf photosynthetic N use efficiency (PNUE)e0
- Direction
- decreasede0
- Qualifier
- 20 days after shoot removale0
Not reportedComparator
Verbatim
e0“leaf photosynthetic N use efficiency (PNUE) were decreased at 20 days after shoot removal”
t0“rapeseed”
Claim · model-written summary
Nitrogen supply increased organ nitrogen content and population biomass.
Not reportedComparator
Verbatim
e0“N supply increased the plant organ N content and PB”
t0“rapeseed”
Claim · model-written summary
Nitrogen supply decreased nitrogen use efficiency at maturity.
Not reportedTreatmentComparator
Verbatim
e0“decreased the NUE at maturity stage”
t0“rapeseed”
Claim · model-written summary
Shoot removal and more nitrogen elevated pod-wall net photosynthetic rate at 25 days after flowering.
- Taxon
- rapeseedt0
- Organ / stage
- pod walle0
- Treatment
- shoot removal and more Ne0
- Outcome
- P n of the pod walle0
- Direction
- elevatede0
- Qualifier
- 25 days after floweringe0
Not reportedComparator
Verbatim
e0“P n of the pod wall at 25 days after flowering was elevated due to its optimized chloroplasts ultrastructure and increased rubisco and sucrose synthase activities under shoot removal and more N”
t0“rapeseed”
Claim · model-written summary
Higher pod-wall amino acid to soluble sugar ratio increased seed protein content.
Verbatim
e0“greater amino acid/soluble sugar ratio (A/S) of the pod wall significantly increased the seed protein content”
t0“rapeseed”
Claim · model-written summary
Higher pod-wall amino acid to soluble sugar ratio decreased seed oil content.
Not reportedOrgan / stage
Verbatim
e0“decreased the oil content”
t0“rapeseed”
Claim · model-written summary
Oil yield with shoot removal and N3 was 63.8-71.0% lower than without shoot removal at N3.
Verbatim
e0“oil yield was reduced by 63.8-71.0% under SR×N3 treatment compared with CK×N3”
t0“rapeseed”
Claim · model-written summary
Oil yield under shoot removal and N3 was comparable to no-removal treatment with 90 kg nitrogen per hectare.
Verbatim
e0“oil yield was reduced by 63.8-71.0% under SR×N3 treatment compared with CK×N3, it was comparable to that of CK with 90 kg N ha −1 treatment”
t0“rapeseed”
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- no effect
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See all 5 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.