Abstract
Summary Three pot experiments have investigated the effects of nitrogen (N) supply on interspecific competition between three weed species ( Phalaris minor Retz., Chenopodium album L, and Sinapis arvensis L.) and spring wheat ( Triticum aestivum L.) cv, Alexandria. The treatments tested included monocultures of each species and a mix‐ture containing them in equal proportions that were combined factorially with two levels of N supply (20, 120 kg N ha ‐1 ). Low N supply decreased net photosynthetic rate (P n ), leaf N percentage, plant dry weight and N uptake of both wheat and weed species and gram dry weight of wheat. The effects of low N on P n and dry weight of weeds were greater than the effects on wheat. In most cases the decrease in P n at low N was due to non‐stomatal factors. The relative competitive abilities of wheat and weeds were influenced by N supply. At high N, S.arvensis was more competitive than wheat, whereas P. minor was less competitive than wheat. C. album was more competitive than wheat at both N levels. The rank order of competitive ability of the weed species was C. album > P. minor > S. arvensis . The effects of interspecific competition on P n were smaller than the effects of N supply and were not associated with corresponding effects on leaf N percentage and plant dry weight of both wheat and weed species and grain dry weight of wheat.
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Claims 9
Claim · model-written summary
Low N supply decreased net photosynthetic rate, leaf N percentage and plant dry weight of wheat and weeds.
- Taxon
- wheat
Triticum aestivume1 - Treatment
- Low N supplye1
- Outcome
- net photosynthetic rate (P n), leaf N percentage, plant dry weighte1
- Direction
- decreasede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Low N supply decreased net photosynthetic rate (P n), leaf N percentage, plant dry weight and N uptake of both wheat and weed species and gram dry weight of wheat”
Claim · model-written summary
Low N supply decreased N uptake of wheat and weeds and gram dry weight of wheat.
- Taxon
- wheatTriticum aestivume1
- Treatment
- Low N supplye1
- Outcome
- N uptake of both wheat and weed species and gram dry weight of wheate1
- Direction
- decreasede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Low N supply decreased net photosynthetic rate (P n), leaf N percentage, plant dry weight and N uptake of both wheat and weed species and gram dry weight of wheat”
Claim · model-written summary
The effects of low N on P n and dry weight of weeds were greater than the effects on wheat.
- Taxon
- wheatTriticum aestivume2
- Treatment
- low Ne2
- Interactor
- weedse2weed
- Outcome
- P n and dry weight of weedse2
- Direction
- greatere2
- Comparator
- wheate2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e2“The effects of low N on P n and dry weight of weeds were greater than the effects on wheat”
Claim · model-written summary
At high N, S. arvensis was more competitive than wheat.
- Taxon
- wheatTriticum aestivume3
- Treatment
- high Ne3
- Interactor
- S.arvensis
Mutarda arvensise3weed - Outcome
- competitivee3
- Direction
- moree3
- Comparator
- wheate3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e3“At high N, S.arvensis was more competitive than wheat, whereas P. minor was less competitive than wheat”
Claim · model-written summary
At high N, P. minor was less competitive than wheat.
- Taxon
- wheatTriticum aestivume3
- Treatment
- high Ne3
- Interactor
- P. minor
.jpg?width=60)
Phalaris minore3weed - Outcome
- competitivee3
- Direction
- lesse3
- Comparator
- wheate3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e3“At high N, S.arvensis was more competitive than wheat, whereas P. minor was less competitive than wheat”
Claim · model-written summary
C. album was more competitive than wheat at both N levels.
- Taxon
- wheatTriticum aestivume4
- Treatment
- both N levelse4
- Interactor
- C. album
Chenopodium albume4weed - Outcome
- competitivee4
- Direction
- moree4
- Comparator
- wheate4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e4“C. album was more competitive than wheat at both N levels”
Claim · model-written summary
The rank order of competitive ability of the weed species was C. album > P. minor > S. arvensis.
- Taxon
- wheatTriticum aestivumt0
- Interactor
- weed speciese6weed
- Outcome
- rank order of competitive ability of the weed speciese6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e6“The rank order of competitive ability of the weed species was C. album > P. minor > S. arvensis”
t0“competition between wheat and three annual weed species”
Claim · model-written summary
The effects of interspecific competition on P n were smaller than the effects of N supply.
- Taxon
- wheatTriticum aestivume7
- Treatment
- interspecific competitione7
- Outcome
- P ne7
- Direction
- smallere7
- Comparator
- N supplye7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e7“The effects of interspecific competition on P n were smaller than the effects of N supply and were not associated with corresponding effects on leaf N percentage and plant dry weight of both wheat and weed species and grain dry weight of wheat”
Claim · model-written summary
Interspecific competition effects on P n were not associated with corresponding effects on leaf N percentage, plant dry weight and grain dry weight of wheat.
- Taxon
- wheatTriticum aestivume7
- Treatment
- interspecific competitione7
- Outcome
- leaf N percentage and plant dry weight of both wheat and weed species and grain dry weight of wheate7
- Direction
- not associated with corresponding effectse7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e7“The effects of interspecific competition on P n were smaller than the effects of N supply and were not associated with corresponding effects on leaf N percentage and plant dry weight of both wheat and weed species and grain dry weight of wheat”
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