Abstract
Abstract Winter canola ( Brassica napus L.) production has increased in the United States over the past several decades; however, there is little research in the southeastern United States on its agronomic production and growth characteristics under different nitrogen (N) fertilizer rates. The objectives of this study were to determine the effects of N rates on winter mortality, yield, oil and protein content, and seedpod shatter resistance across cultivars. Canola was grown in a randomized split complete block design with four replicates under five different N rates (0, 56, 112, 168, and 224 kg N ha −1 ) with four different cultivars (Hekip, Inspiration, and Edimax CL or Phoenix CL). Seed yield was very low for the 2017–2018 season, likely due to extreme cold conditions in winter and/or frost at flowering. There was high winter mortality during this period, but Edimax CL had significantly lower mortality (79.7%) than Inspiration (85.7%) and Hekip (83.9%). In the following year, more mild temperatures led to low mortality and greater yields, where rates of 112, 168, and 224 kg N ha −1 had the greatest yields (1,612–1,857 kg ha −1 ) with no significant differences according to cultivar. In 2018, shatter resistance was greatest for the rates of 112, 168, and 224 kg N ha −1 and was positively related to N rate. Across both years, Inspiration had greater shatter resistance. In 2019, the lowest N rate (0 kg N ha −1 ) and Phoenix CL had significantly greater oil contents (48.4 and 47.3%, respectively), whereas the highest N rate (224 kg N ha −1 ) with no particular cultivar had a significantly greater protein content (21.0%).
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Claims 14
Claim · model-written summary
Seed yield was very low in 2017–2018, possibly due to winter cold or flowering frost.
- Taxon
- canola
.jpg?width=60)
Brassica napus var. napust0 - Outcome
- Seed yielde0
- Direction
- very lowe0
- Qualifier
- likely due to extreme cold conditions in winter and/or frost at floweringe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e0“Seed yield was very low for the 2017–2018 season, likely due to extreme cold conditions in winter and/or frost at flowering”
t0“winter canola cultivar on seed yield”
Claim · model-written summary
Winter mortality was high in 2017–2018.
- Taxon
- canolaBrassica napus var. napust0
- Outcome
- winter mortalitye0
- Direction
- highe0
- Qualifier
- 2017–2018 seasone1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“There was high winter mortality during this period”
t0“winter canola cultivar on seed yield”
e1“Seed yield was very low for the 2017–2018 season”
Claim · model-written summary
Edimax CL mortality of 79.7% was significantly lower than Inspiration mortality of 85.7%.
- Taxon
- canolaBrassica napus var. napust0
- Material
- Edimax CLe0
- Outcome
- mortalitye0
- Direction
- lowere0
- Value
- 79.7%e0
- Qualifier
- 85.7%e0
- Comparator
- Inspiratione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Edimax CL had significantly lower mortality (79.7%) than Inspiration (85.7%)”
t0“winter canola cultivar on seed yield”
Claim · model-written summary
Edimax CL mortality of 79.7% was significantly lower than Hekip mortality of 83.9%.
- Taxon
- canolaBrassica napus var. napust0
- Material
- Edimax CLe0
- Outcome
- mortalitye0
- Direction
- lowere0
- Value
- 79.7%e0
- Qualifier
- 83.9%e0
- Comparator
- Hekipe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Edimax CL had significantly lower mortality (79.7%) than Inspiration (85.7%) and Hekip (83.9%)”
t0“winter canola cultivar on seed yield”
Claim · model-written summary
Milder following year had lower mortality.
- Taxon
- canolaBrassica napus var. napust0
- Outcome
- mortalitye0
- Direction
- lowe0
- Setting
- more mild temperaturese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“more mild temperatures led to low mortality and greater yields”
t0“winter canola cultivar on seed yield”
Claim · model-written summary
Milder following year had greater yields.
- Taxon
- canolaBrassica napus var. napust0
- Outcome
- yieldse0
- Direction
- greatere0
- Setting
- more mild temperaturese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“more mild temperatures led to low mortality and greater yields”
t0“winter canola cultivar on seed yield”
Claim · model-written summary
Nitrogen rates of 112, 168 and 224 kg N ha −1 produced greatest yields of 1,612–1,857 kg ha −1.
- Taxon
- canolaBrassica napus var. napust0
- Treatment
- 112, 168, and 224 kg N ha −1e0
- Outcome
- yieldse0
- Direction
- greateste0
- Value
- 1,612–1,857 kg ha −1e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“rates of 112, 168, and 224 kg N ha −1 had the greatest yields (1,612–1,857 kg ha −1 )”
t0“winter canola cultivar on seed yield”
Claim · model-written summary
Yield did not significantly differ by cultivar in the following year.
- Taxon
- canolaBrassica napus var. napust0
- Outcome
- yieldse1
- Direction
- no significant differencese0
- Comparator
- cultivare0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“with no significant differences according to cultivar”
t0“winter canola cultivar on seed yield”
e1“rates of 112, 168, and 224 kg N ha −1 had the greatest yields (1,612–1,857 kg ha −1 )”
Claim · model-written summary
Shatter resistance was greatest at 112, 168 and 224 kg N ha −1.
- Taxon
- canolaBrassica napus var. napust0
- Treatment
- 112, 168, and 224 kg N ha −1e0
- Outcome
- shatter resistancee0
- Direction
- greateste0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“shatter resistance was greatest for the rates of 112, 168, and 224 kg N ha −1”
t0“winter canola cultivar on seed yield”
Claim · model-written summary
Shatter resistance rose with nitrogen rate.
- Taxon
- canolaBrassica napus var. napust0
- Treatment
- N ratee0
- Outcome
- shatter resistancee0
- Direction
- positively relatede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“shatter resistance was greatest for the rates of 112, 168, and 224 kg N ha −1 and was positively related to N rate”
t0“winter canola cultivar on seed yield”
Claim · model-written summary
Inspiration had greater shatter resistance across years.
- Taxon
- canolaBrassica napus var. napust0
- Material
- Inspiratione0
- Outcome
- shatter resistancee0
- Direction
- greatere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Across both years, Inspiration had greater shatter resistance”
t0“winter canola cultivar on seed yield”
Claim · model-written summary
Zero nitrogen rate gave significantly greater oil content of 48.4%.
- Taxon
- canolaBrassica napus var. napust0
- Treatment
- 0 kg N ha −1e0
- Outcome
- oil contentse0
- Direction
- greatere0
- Value
- 48.4e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the lowest N rate (0 kg N ha −1 ) and Phoenix CL had significantly greater oil contents (48.4 and 47.3%, respectively)”
t0“winter canola cultivar on seed yield”
Claim · model-written summary
Phoenix CL had significantly greater oil content of 47.3%.
- Taxon
- canolaBrassica napus var. napust0
- Material
- Phoenix CLe0
- Outcome
- oil contentse0
- Direction
- greatere0
- Value
- 47.3%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Phoenix CL had significantly greater oil contents (48.4 and 47.3%, respectively)”
t0“winter canola cultivar on seed yield”
Claim · model-written summary
Highest nitrogen rate gave significantly greater protein content of 21.0%.
- Taxon
- canolaBrassica napus var. napust0
- Treatment
- 224 kg N ha −1e0
- Outcome
- protein contente0
- Direction
- greatere0
- Value
- 21.0%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the highest N rate (224 kg N ha −1 ) with no particular cultivar had a significantly greater protein content (21.0%)”
t0“winter canola cultivar on seed yield”
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