Abstract
Palmer amaranth ( Amaranthus palmeri S. Wats.) has become difficult to control in row crops due to selection for biotypes that are no longer controlled by acetolactate synthase inhibiting herbicides and/or glyphosate. Early season interference in soybean [ Glycine max (L.) Merr.] for 40 days after emergence by three glyphosate-resistant (GR) and three glyphosate-susceptible (GS) Palmer amaranth biotypes from Georgia and North Carolina was compared in the greenhouse. A field experiment over 2 years compared season-long interference of these biotypes in soybean. The six Palmer amaranth biotypes reduced soybean height similarly in the greenhouse but did not affect soybean height in the field. Reduction in soybean fresh weight and dry weight in the greenhouse; and soybean yield in the field varied by Palmer amaranth biotypes. Soybean yield was reduced 21% by Palmer amaranth at the established field density of 0.37 plant m −2 . When Palmer amaranth biotypes were grouped by response to glyphosate, the GS group reduced fresh weight, dry weight, and yield of soybean more than the GR group. The results indicate a possible small competitive disadvantage associated with glyphosate resistance, but observed differences among biotypes might also be associated with characteristics within and among biotypes other than glyphosate resistance.
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Claims 7
Claim · model-written summary
Six Palmer amaranth biotypes similarly reduced soybean height in the greenhouse.
- Taxon
- soybean
Glycine maxe0 - Treatment
- six Palmer amaranth biotypese0
- Interactor
- Palmer amaranthe0weed
- Outcome
- soybean heighte0
- Direction
- reducede0
- Setting
- greenhousee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The six Palmer amaranth biotypes reduced soybean height similarly in the greenhouse”
Claim · model-written summary
The six Palmer amaranth biotypes did not affect soybean height in the field.
- Taxon
- soybeanGlycine maxe0
- Treatment
- six Palmer amaranth biotypese0
- Interactor
- Palmer amaranthe0weed
- Outcome
- soybean heighte0
- Direction
- did not affecte0
- Setting
- fielde0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The six Palmer amaranth biotypes reduced soybean height similarly in the greenhouse but did not affect soybean height in the field”
Claim · model-written summary
Greenhouse soybean fresh and dry weight reductions varied by Palmer amaranth biotype.
- Taxon
- soybeanGlycine maxe0
- Interactor
- Palmer amaranthe0weed
- Outcome
- soybean fresh weight and dry weighte0
- Direction
- Reductione0
- Setting
- greenhousee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Reduction in soybean fresh weight and dry weight in the greenhouse; and soybean yield in the field varied by Palmer amaranth biotypes”
Claim · model-written summary
Field soybean yield reduction varied by Palmer amaranth biotype.
- Taxon
- soybeanGlycine maxe0
- Interactor
- Palmer amaranthe0weed
- Outcome
- soybean yielde0
- Setting
- fielde0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“soybean yield in the field varied by Palmer amaranth biotypes”
e1“Reduction in soybean fresh weight and dry weight in the greenhouse”
Claim · model-written summary
Palmer amaranth at 0.37 plant m −2 reduced soybean yield by 21%.
- Taxon
- SoybeanGlycine maxe0
- Treatment
- Palmer amaranth at the established field density of 0.37 plant m −2e0
- Interactor
- Palmer amaranthe0weed
- Outcome
- Soybean yielde0
- Direction
- reducede0
- Value
- 21%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Soybean yield was reduced 21% by Palmer amaranth at the established field density of 0.37 plant m −2”
Claim · model-written summary
Glyphosate-susceptible Palmer amaranth reduced soybean fresh weight, dry weight and yield more than glyphosate-resistant biotypes.
- Taxon
- soybeanGlycine maxe0
- Treatment
- GS groupe0
- Interactor
- Palmer amaranthe1weed
- Outcome
- fresh weight, dry weight, and yield of soybeane0
- Direction
- reducede0
- Comparator
- GR groupe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the GS group reduced fresh weight, dry weight, and yield of soybean more than the GR group”
e1“Palmer amaranth biotypes were grouped by response to glyphosate”
Claim · model-written summary
The authors infer a possible small competitive disadvantage associated with glyphosate resistance in Palmer amaranth, while noting other biotype traits could explain the differences.
- Taxon
- soybeanGlycine maxe1
- Interactor
- Palmer amaranthe2weed
- Outcome
- competitive disadvantagee0
- Qualifier
- characteristics within and among biotypes other than glyphosate resistancee0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“possible small competitive disadvantage associated with glyphosate resistance, but observed differences among biotypes might also be associated with characteristics within and among biotypes other than glyphosate resistance”
e1“yield of soybean more than the GR group”
e2“When Palmer amaranth biotypes were grouped by response to glyphosate”
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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.