Abstract
Russian knapweed is an invasive creeping perennial herb which affects crops by competition and allelopathy. Herbicides available for use in onion are not able to control Russian knapweed in a crop context. Conversely, recommended products for Russian knapweed are not selective for the crop. The aims of this work were to study Russian knapweed biomass production and propagation for a range of increasing densities in an experimental onion culture and to characterize the productive response of onion plants under these conditions. A partial additive experiment was carried out to study Russian knapweed interference (variable density, 0-64 ramet m-2) on onion transplants (constant density, 40 pl m-2) under greenhouse conditions in Viedma, Argentina (40? 03' S; 62? 48' O). Although no differences among treatments were found for weed final aboveground biomass, low density treatments (0, 2 ramet m-2) were lower than 64 ramet m-2 for belowground biomass. Final weed density was proportional to initial conditions. For onion, total (-54%) and commercial bulb yield (- 56 %) were reduced by weed competition with > 32 ramet m-2. While size 3 bulbs (50-70 mm eq. diam.) were less represented at weed densities higher than 16 ramets m-2, size 4 ones (70-90 mm eq. diam.) were not present in this condition. For A. repens, traits such as the rate of vegetative propagation, high competitive ability, mainly belowground, and high propagule pressure support its high invasive potential.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 8
Claim · model-written summary
Final Russian knapweed aboveground biomass did not differ among treatments.
- Taxon
- onion
Allium cepat0 - Treatment
- treatmentse0
- Interactor
- Russian knapweed
Leuzea repenst1weed - Outcome
- weed final aboveground biomasse0
- Direction
- no differencese0
- Comparator
- among treatmentse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“onion”
t1“Russian knapweed”
e0“no differences among treatments were found for weed final aboveground biomass”
Claim · model-written summary
Belowground knapweed biomass at low densities was lower than at 64 ramets per square metre.
- Taxon
- onionAllium cepat0
- Treatment
- low density treatments (0, 2 ramet m-2)e0
- Interactor
- Russian knapweedLeuzea repenst1weed
- Outcome
- belowground biomasse0
- Direction
- lowere0
- Comparator
- 64 ramet m-2e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t1“Russian knapweed”
t0“onion”
e0“low density treatments (0, 2 ramet m-2) were lower than 64 ramet m-2 for belowground biomass”
Claim · model-written summary
Final weed density was proportional to initial density.
- Taxon
- onionAllium cepat0
- Treatment
- initial conditionse0
- Interactor
- Russian knapweedLeuzea repenst1weedt0
- Outcome
- Final weed densitye0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t1“Russian knapweed”
t0“onion”
e0“Final weed density was proportional to initial conditions”
Claim · model-written summary
Onion total bulb yield fell 54% with weed density above 32 ramets per square metre.
- Taxon
- onionAllium cepat0
- Treatment
- weed competition with > 32 ramet m-2e0
- Interactor
- Russian knapweedLeuzea repenst1weedt0
- Outcome
- totale0
- Direction
- reducede0
- Value
- -54%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“onion”
t1“Russian knapweed”
e0“total (-54%) and commercial bulb yield (- 56 %) were reduced by weed competition with > 32 ramet m-2”
Claim · model-written summary
Onion commercial bulb yield fell 56% with weed density above 32 ramets per square metre.
- Taxon
- onionAllium cepat0
- Treatment
- weed competition with > 32 ramet m-2e0
- Interactor
- Russian knapweedLeuzea repenst1weedt0
- Outcome
- commercial bulb yielde0
- Direction
- reducede0
- Value
- - 56 %e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“onion”
t1“Russian knapweed”
e0“total (-54%) and commercial bulb yield (- 56 %) were reduced by weed competition with > 32 ramet m-2”
Claim · model-written summary
Size 3 bulbs were less represented above 16 ramets per square metre.
- Taxon
- onionAllium cepat0
- Treatment
- weed densities higher than 16 ramets m-2e0
- Interactor
- Russian knapweedLeuzea repenst1weedt0
- Outcome
- size 3 bulbse0
- Direction
- less representede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“onion”
t1“Russian knapweed”
e0“size 3 bulbs (50-70 mm eq. diam.) were less represented at weed densities higher than 16 ramets m-2”
Claim · model-written summary
Size 4 bulbs were absent above 16 ramets per square metre.
- Taxon
- onionAllium cepat0
- Treatment
- this conditione0
- Interactor
- Russian knapweedLeuzea repenst1weedt0
- Outcome
- size 4 onese0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“onion”
t1“Russian knapweed”
e0“size 4 ones (70-90 mm eq. diam.) were not present in this condition”
Claim · model-written summary
The authors attribute invasive potential of A. repens to vegetative propagation, belowground competition and propagule pressure.
- Taxon
- onionAllium cepat0
- Interactor
- A. repense0weed
- Outcome
- high invasive potentiale0
- Qualifier
- rate of vegetative propagation, high competitive ability, mainly belowground, and high propagule pressuree0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“onion”
e0“For A. repens, traits such as the rate of vegetative propagation, high competitive ability, mainly belowground, and high propagule pressure support its high invasive potential”