Abstract
Giant ragweed (Ambrosia trifida L.) is competitive with agronomic crops and can cause significant yield losses. Rapid adoption of glyphosate-resistant (GR) crops and a concomitant increase in the reliance on glyphosate for weed management has led to the evolution of GR giant ragweed in Ontario, Canada. Field studies were conducted to evaluate the level of resistance in giant ragweed biotypes from Ontario, and to evaluate the effectiveness of various postemer-gence (POST) herbicides in soybean (Glycine max L.). The effective dose (ED) to provide 50%, 80% and 95% giant ragweed control was up to 1658, 9991 and >43200 g?a.e.?ha–1 4 weeks after application (WAA), respectively. For effective control, growers would need to apply glyphosate 18 times greater than the recommended field application dose. Glyphosate applied at the recommended field dose of 900 g?a.e.?ha–1 provided up to 57% control and resulted in soybean yield equivalent to the weedy check. Cloransulam-methyl applied POST provided up to 99% control, reduced giant ragweed density 98%, reduced giant ragweed shoot dry weight 99% and resulted in soybean yield equivalent to the weedfree check. Chlorimuron-ethyl, fomesafen, imazethapyr and imazethapyr plus bentazon applied alone or with glyphosate did not provide adequate control of GR giant ragweed. Based on these results, some GR giant ragweed biotypes from Ontario have evolved a high level of resistance to glyphosate. Cloransulam-methyl applied POST was the only herbicide that provided adequate control and suggests that additional weed management tactics will need to be implemented in order to effectively manage GR giant ragweed.
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Claims 16
Claim · model-written summary
The effective dose for 50% giant ragweed control was up to 1658 g a.e. ha-1 at 4 weeks after application.
- Taxon
- Giant ragweed
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Ambrosia trifidae0 - Outcome
- effective dose (ED)e2
- Value
- 1658e2
- Qualifier
- 4 weeks after application (WAA)e2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e0“Giant ragweed (Ambrosia trifida L.) is competitive with agronomic crops”
e2“The effective dose (ED) to provide 50%, 80% and 95% giant ragweed control was up to 1658, 9991 and >43200 g?a.e.?ha–1 4 weeks after application (WAA), respectively”
Claim · model-written summary
The effective dose for 80% giant ragweed control was up to 9991 g a.e. ha-1 at 4 weeks after application.
- Taxon
- Giant ragweedAmbrosia trifidae0
- Outcome
- effective dose (ED)e2
- Value
- 9991e2
- Qualifier
- 4 weeks after application (WAA)e2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Giant ragweed (Ambrosia trifida L.) is competitive with agronomic crops”
e2“The effective dose (ED) to provide 50%, 80% and 95% giant ragweed control was up to 1658, 9991 and >43200 g?a.e.?ha–1 4 weeks after application (WAA), respectively”
Claim · model-written summary
The effective dose for 95% giant ragweed control was above 43200 g a.e. ha-1 at 4 weeks after application.
- Taxon
- Giant ragweedAmbrosia trifidae0
- Outcome
- effective dose (ED)e2
- Value
- >43200e2
- Qualifier
- 4 weeks after application (WAA)e2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Giant ragweed (Ambrosia trifida L.) is competitive with agronomic crops”
e2“The effective dose (ED) to provide 50%, 80% and 95% giant ragweed control was up to 1658, 9991 and >43200 g?a.e.?ha–1 4 weeks after application (WAA), respectively”
Claim · model-written summary
Glyphosate at the recommended field dose of 900 g a.e. ha-1 provided up to 57% giant ragweed control.
- Taxon
- Giant ragweedAmbrosia trifidae0
- Treatment
- Glyphosate applied at the recommended field dose of 900 g?a.e.?ha–1e3
- Outcome
- controle3
- Value
- 57%e3
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Giant ragweed (Ambrosia trifida L.) is competitive with agronomic crops”
e3“Glyphosate applied at the recommended field dose of 900 g?a.e.?ha–1 provided up to 57% control and resulted in soybean yield equivalent to the weedy check”
Claim · model-written summary
Glyphosate at the recommended field dose gave soybean yield equivalent to the weedy check, so the yield was not improved.
- Taxon
- soybean
Glycine maxe3 - Treatment
- Glyphosate applied at the recommended field dose of 900 g?a.e.?ha–1e3
- Interactor
- Giant ragweedAmbrosia trifidae0weed
- Outcome
- soybean yielde3
- Direction
- equivalente3
- Comparator
- weedy checke3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Giant ragweed (Ambrosia trifida L.) is competitive with agronomic crops”
e3“Glyphosate applied at the recommended field dose of 900 g?a.e.?ha–1 provided up to 57% control and resulted in soybean yield equivalent to the weedy check”
Claim · model-written summary
Cloransulam-methyl applied POST provided up to 99% giant ragweed control.
- Taxon
- Giant ragweedAmbrosia trifidae0
- Treatment
- Cloransulam-methyl applied POSTe4
- Outcome
- controle4
- Value
- 99%e4
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Giant ragweed (Ambrosia trifida L.) is competitive with agronomic crops”
e4“Cloransulam-methyl applied POST provided up to 99% control, reduced giant ragweed density 98%, reduced giant ragweed shoot dry weight 99% and resulted in soybean yield equivalent to the weedfree check”
Claim · model-written summary
Cloransulam-methyl applied POST reduced giant ragweed density by 98%.
- Taxon
- Giant ragweedAmbrosia trifidae0
- Treatment
- Cloransulam-methyl applied POSTe4
- Outcome
- giant ragweed densitye4
- Direction
- reducede4
- Value
- 98%e4
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Giant ragweed (Ambrosia trifida L.) is competitive with agronomic crops”
e4“Cloransulam-methyl applied POST provided up to 99% control, reduced giant ragweed density 98%, reduced giant ragweed shoot dry weight 99% and resulted in soybean yield equivalent to the weedfree check”
Claim · model-written summary
Cloransulam-methyl applied POST reduced giant ragweed shoot dry weight by 99%.
- Taxon
- Giant ragweedAmbrosia trifidae0
- Treatment
- Cloransulam-methyl applied POSTe4
- Outcome
- giant ragweed shoot dry weighte4
- Direction
- reducede4
- Value
- 99%e4
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Giant ragweed (Ambrosia trifida L.) is competitive with agronomic crops”
e4“Cloransulam-methyl applied POST provided up to 99% control, reduced giant ragweed density 98%, reduced giant ragweed shoot dry weight 99% and resulted in soybean yield equivalent to the weedfree check”
Claim · model-written summary
Cloransulam-methyl applied POST gave soybean yield equivalent to the weedfree check.
- Taxon
- soybeanGlycine maxe4
- Treatment
- Cloransulam-methyl applied POSTe4
- Interactor
- giant ragweedAmbrosia trifidae4weed
- Outcome
- soybean yielde4
- Direction
- equivalente4
- Comparator
- weedfree checke4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e4“Cloransulam-methyl applied POST provided up to 99% control, reduced giant ragweed density 98%, reduced giant ragweed shoot dry weight 99% and resulted in soybean yield equivalent to the weedfree check”
Claim · model-written summary
Chlorimuron-ethyl did not provide adequate giant ragweed control, alone or with glyphosate.
- Taxon
- Giant ragweedAmbrosia trifidae0
- Treatment
- Chlorimuron-ethyle5
- Outcome
- adequate controle5
- Direction
- did not providee5
- Qualifier
- applied alone or with glyphosatee5
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Giant ragweed (Ambrosia trifida L.) is competitive with agronomic crops”
e5“Chlorimuron-ethyl, fomesafen, imazethapyr and imazethapyr plus bentazon applied alone or with glyphosate did not provide adequate control of GR giant ragweed”
Claim · model-written summary
Fomesafen did not provide adequate giant ragweed control, alone or with glyphosate.
- Taxon
- Giant ragweedAmbrosia trifidae0
- Treatment
- fomesafene5
- Outcome
- adequate controle5
- Direction
- did not providee5
- Qualifier
- applied alone or with glyphosatee5
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Giant ragweed (Ambrosia trifida L.) is competitive with agronomic crops”
e5“Chlorimuron-ethyl, fomesafen, imazethapyr and imazethapyr plus bentazon applied alone or with glyphosate did not provide adequate control of GR giant ragweed”
Claim · model-written summary
Imazethapyr did not provide adequate giant ragweed control, alone or with glyphosate.
- Taxon
- Giant ragweedAmbrosia trifidae0
- Treatment
- imazethapyre5
- Outcome
- adequate controle5
- Direction
- did not providee5
- Qualifier
- applied alone or with glyphosatee5
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Giant ragweed (Ambrosia trifida L.) is competitive with agronomic crops”
e5“Chlorimuron-ethyl, fomesafen, imazethapyr and imazethapyr plus bentazon applied alone or with glyphosate did not provide adequate control of GR giant ragweed”
Claim · model-written summary
Imazethapyr plus bentazon did not provide adequate giant ragweed control, alone or with glyphosate.
- Taxon
- Giant ragweedAmbrosia trifidae0
- Treatment
- imazethapyr plus bentazone5
- Outcome
- adequate controle5
- Direction
- did not providee5
- Qualifier
- applied alone or with glyphosatee5
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Giant ragweed (Ambrosia trifida L.) is competitive with agronomic crops”
e5“Chlorimuron-ethyl, fomesafen, imazethapyr and imazethapyr plus bentazon applied alone or with glyphosate did not provide adequate control of GR giant ragweed”
Claim · model-written summary
Cloransulam-methyl applied POST was the only herbicide that gave adequate giant ragweed control.
- Taxon
- Giant ragweedAmbrosia trifidae0
- Treatment
- Cloransulam-methyl applied POSTe7
- Outcome
- adequate controle7
- Direction
- was the only herbicide that providede7
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Giant ragweed (Ambrosia trifida L.) is competitive with agronomic crops”
e7“Cloransulam-methyl applied POST was the only herbicide that provided adequate control and suggests that additional weed management tactics will need to be implemented in order to effectively manage GR giant ragweed”
Claim · model-written summary
Some giant ragweed biotypes from Ontario have evolved a high level of resistance to glyphosate.
- Taxon
- giant ragweedAmbrosia trifidae6
- Material
- GR giant ragweed biotypese6
- Outcome
- resistance to glyphosatee6
- Qualifier
- high levele6
- Setting
- Ontarioe6
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e6“some GR giant ragweed biotypes from Ontario have evolved a high level of resistance to glyphosate”
Claim · model-written summary
The authors suggest that additional weed management tactics are needed to manage giant ragweed effectively.
- Taxon
- giant ragweedAmbrosia trifidae7
- Outcome
- additional weed management tacticse7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e7“Cloransulam-methyl applied POST was the only herbicide that provided adequate control and suggests that additional weed management tactics will need to be implemented in order to effectively manage GR giant ragweed”
The same questions in other papers
bentazone · control · Ambrosia trifida (giant ragweed)Positive and negative results
1 in the opposite direction
- positive
fomesafen · control · Ambrosia trifida (giant ragweed)Positive and negative results
2 in the opposite direction
- positive
- positive
glyphosate · Ambrosia trifida · Glycine max (soybean)Positive and negative results
11 in the opposite direction
- positive
- positive
- positive
8 papers more in this group
See all 12 papers →glyphosate · control · Ambrosia trifida (giant ragweed)Results agree
1 paper in the same direction as this paper
- positive
cloransulam-methyl · Ambrosia trifida · Glycine max (soybean)Results agree
2 papers in the same direction as this paper
- positive
- positive
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.