Abstract
Core Ideas The application of glyphosate during early reproductive growth resulted in significant declines in yield. Decreased yields with late‐season herbicides were associated with an increased number of aborted pods; however, this may not be the only factor contributing to the yield decline. Seed oil content followed the same general trend as grain yield, with decreased oil yields when glyphosate was applied during early reproductive growth. In canola ( Brassica napus L.), control of grassy weeds can typically be achieved in the fall or spring with timely herbicide applications. However, environmental conditions can delay these applications into canola reproductive growth stages, which have an unknown effect on canola productivity. Therefore, a study was conducted to determine the impact of late‐season herbicide applications on canola grain yields and seed quality. The impact of three herbicides (glyphosate [ N ‐(phosphonomethyl)glycine], clethodim [(E)‐2‐[1‐[[3‐chloro‐2‐propenyl)oxy]imino]propyl]5=[2‐(ethylthio)propyl]‐2‐hydroxy‐2‐cyclohexen‐1‐one], and quizalofop‐P‐ethyl [Ethyl(R)‐2‐[4‐(6‐chloroquinoxalin‐2‐yloxy)‐phenoxy]propionate]) and three applications timings (bolting, early flower, and mid‐flower) were investigated on winter canola from 2015 through 2018 in Perkins and Stillwater, OK. Grain yields and pod abortion were collected at maturity. Subsamples of harvested seed were collected from each plot and used for oil analysis. When averaged across years, the application of glyphosate at bolting and early flower resulted in yield decreases of 531 and 488 kg ha –1 compared with the nontreated control. Yield following the application of clethodim at early flower resulted in a 185 kg ha –1 (2017) and 280 (2018) kg ha –1 decrease in yields compared with the control. Although yield decreases were observed following a few treatments, a significant increase in pod abortion was noted following many herbicide treatments, indicating that pod abortion was not the only factor contributing to yield declines. Decreases in oil content were only found following glyphosate applications at bolting and early flower. These results indicate that late‐season herbicide applications, especially glyphosate, should be avoided in winter canola.
Abstract from the paper’s OpenAlex record; open copy licensed cc-by-nc-nd. 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 10
Claim · model-written summary
Glyphosate at bolting reduced winter canola grain yield by 531 kg ha –1 versus untreated control.
- Taxon
- winter canola
.jpg?width=60)
Brassica napus var. napust0 - Treatment
- glyphosate at boltinge0
- Outcome
- yielde0
- Direction
- decreasese0
- Value
- 531e0
- Comparator
- nontreated controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e0“the application of glyphosate at bolting and early flower resulted in yield decreases of 531 and 488 kg ha –1 compared with the nontreated control”
t0“Winter Canola”
Claim · model-written summary
Glyphosate at early flower reduced winter canola grain yield by 488 kg ha –1 versus untreated control.
- Taxon
- winter canolaBrassica napus var. napust0
- Treatment
- glyphosate at bolting and early flowere0
- Outcome
- yielde0
- Direction
- decreasese0
- Value
- 488 kg ha –1e0
- Comparator
- nontreated controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the application of glyphosate at bolting and early flower resulted in yield decreases of 531 and 488 kg ha –1 compared with the nontreated control”
t0“Winter Canola”
Claim · model-written summary
Clethodim at early flower reduced canola yield by 185 kg ha –1 in 2017.
- Taxon
- canolaBrassica napus var. napust0
- Treatment
- clethodim at early flowere0
- Outcome
- yieldse0
- Direction
- decreasee0
- Value
- 185 kg ha –1e0
- Qualifier
- 2017e0
- Comparator
- controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“clethodim at early flower resulted in a 185 kg ha –1 (2017) and 280 (2018) kg ha –1 decrease in yields compared with the control”
t0“Canola Yield”
Claim · model-written summary
Clethodim at early flower reduced canola yield by 280 kg ha –1 in 2018.
- Taxon
- canolaBrassica napus var. napust0
- Treatment
- clethodim at early flowere0
- Outcome
- yieldse0
- Direction
- decreasee0
- Value
- 280 (2018) kg ha –1e0
- Comparator
- controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“clethodim at early flower resulted in a 185 kg ha –1 (2017) and 280 (2018) kg ha –1 decrease in yields compared with the control”
t0“Canola Yield”
Claim · model-written summary
Many late-season herbicide treatments significantly increased pod abortion.
- Taxon
- canolaBrassica napus var. napust0
- Treatment
- herbicide treatmentse0
- Outcome
- pod abortione0
- Direction
- increasee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a significant increase in pod abortion was noted following many herbicide treatments”
t0“Canola Yield”
Claim · model-written summary
Yield decline with late-season herbicides was associated with increased pod abortion, although the authors considered other factors likely.
- Taxon
- canolaBrassica napus var. napust0
- Treatment
- late‐season herbicidese0
- Outcome
- yieldse0
- Direction
- Decreasede0
- Qualifier
- this may not be the only factor contributing to the yield declinee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Decreased yields with late‐season herbicides were associated with an increased number of aborted pods; however, this may not be the only factor contributing to the yield decline”
t0“Canola Yield”
Claim · model-written summary
Glyphosate at bolting decreased canola seed oil content.
- Taxon
- canolaBrassica napus var. napust0
- Treatment
- glyphosate applications at boltinge0
- Outcome
- oil contente0
- Direction
- Decreasese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Decreases in oil content were only found following glyphosate applications at bolting and early flower”
t0“Canola Yield”
Claim · model-written summary
Glyphosate at early flower decreased canola seed oil content.
- Taxon
- canolaBrassica napus var. napust0
- Treatment
- glyphosate applications at bolting and early flowere0
- Outcome
- oil contente0
- Direction
- Decreasese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Decreases in oil content were only found following glyphosate applications at bolting and early flower”
t0“Canola Yield”
Claim · model-written summary
Glyphosate during early reproductive growth decreased canola oil yield.
- Taxon
- canolaBrassica napus var. napust0
- Treatment
- glyphosate was applied during early reproductive growthe0
- Outcome
- oil yieldse0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“decreased oil yields when glyphosate was applied during early reproductive growth”
t0“Canola Yield”
Claim · model-written summary
The authors recommend avoiding late-season herbicide applications, especially glyphosate, in winter canola.
- Taxon
- winter canolaBrassica napus var. napuse0
- Outcome
- late‐season herbicide applications, especially glyphosate, should be avoidede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“late‐season herbicide applications, especially glyphosate, should be avoided in winter canola”
The same questions in other papers
glyphosate · quality: oil · Brassica napus (oilseed rape)Results differ
1 paper in the same direction as this paper · 1 in the opposite direction
- positive
- no effect
clethodim · yield · Brassica napus (oilseed rape)Results differ
1 paper in the same direction as this paper · 1 in the opposite direction
- positive
- no effect
glyphosate · yield · Brassica napus (oilseed rape)Results differ
2 papers in the same direction as this paper · 6 in the opposite direction
- positive
- positive
- negative
5 papers more in this group
See all 9 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.