Abstract
Oil concentration and seed yield of canola ( Brassica napus ) are usually low and variable when grown in the lower rainfall areas of Western Australia. This paper identifies determinants of oil concentration and seed yield in these areas. Through a series of cultivar × sowing date experiments at 5 lower rainfall locations and one high rainfall location as comparison, we evaluated the impact of sowing date, cultivar, and location on these 2 key agronomic traits. We also examined relationships between oil concentration, seed yield, and post-anthesis duration, post-anthesis temperature, and post-anthesis rainfall with a view to investigate the adaptive requirements of canola for the lower rainfall areas. Cultivars differed in their capacities to produce oil and seed yield. The ranking of cultivars for oil concentration, and seed yield to a lesser extent, remained constant across sowing dates and locations. Both seed yield and oil concentration decreased with delayed sowing. On average, oil concentration was reduced by 1.1 percentage points and seed yield by 309 kg/ha for every 2 weeks delay in sowing. The magnitude of reduction in oil concentration from delayed sowing was far greater in a low rainfall site at Mullewa than in the high rainfall site at Mt Barker. Later sowings shortened post-anthesis duration. With a given sowing date, early flowering cultivars resulted in longer post-anthesis duration. Oil concentration increased by 1.2 percentage points for a 10-day increase in post-anthesis duration. Both oil concentration and seed yield increased with higher post-anthesis rainfall and lower post-anthesis temperature. The rates of increase were 0.7 percentage points for oil and 116 kg/ha for seed yield for every 10-mm increase in post-anthesis rainfall. The rates of reduction were 0.68 percentage points for oil and 289 kg/ha for seed yield for every 1°C increase in post-anthesis temperature. These relationships suggest that a combination of an early date of sowing with an early flowering cultivar would be essential for the production of high yield and high oil canola in the lower rainfall areas. Indian mustard ( B. juncea ) showed tolerance to high temperature and water deficit, but the low yield potential makes it uneconomical with early sowing. Further improvement in seed yield could be dependent on increased tolerance of canola to high temperature and water deficit during seed growth and development.
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Claims 17
Claim · model-written summary
Cultivars differed in oil production and seed yield.
- Taxon
- canola
.jpg?width=60)
Brassica napus var. napuse1 - Material
- Cultivarse0
- Outcome
- oil and seed yielde0
- Direction
- differede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e0“Cultivars differed in their capacities to produce oil and seed yield”
e1“canola ( Brassica napus )”
Claim · model-written summary
Cultivar oil-concentration rankings stayed constant across sowing dates and locations.
- Taxon
- canolaBrassica napus var. napuse1
- Material
- cultivarse0
- Outcome
- oil concentratione0
- Direction
- remained constante0
- Setting
- locationse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The ranking of cultivars for oil concentration, and seed yield to a lesser extent, remained constant across sowing dates and locations”
e1“canola ( Brassica napus )”
Claim · model-written summary
Cultivar seed-yield rankings were less stable across sowing dates and locations.
- Taxon
- canolaBrassica napus var. napuse1
- Material
- cultivarse0
- Outcome
- seed yielde0
- Direction
- remained constante0
- Qualifier
- to a lesser extente0
- Setting
- locationse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The ranking of cultivars for oil concentration, and seed yield to a lesser extent, remained constant across sowing dates and locations”
e1“canola ( Brassica napus )”
Claim · model-written summary
Every two-week sowing delay reduced oil concentration by 1.1 percentage points.
- Taxon
- canolaBrassica napus var. napuse1
- Treatment
- every 2 weeks delay in sowinge0
- Outcome
- oil concentratione0
- Direction
- reducede0
- Value
- 1.1 percentage pointse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“oil concentration was reduced by 1.1 percentage points and seed yield by 309 kg/ha for every 2 weeks delay in sowing”
e1“canola ( Brassica napus )”
Claim · model-written summary
Every two-week sowing delay reduced seed yield by 309 kg/ha.
- Taxon
- canolaBrassica napus var. napuse1
- Treatment
- every 2 weeks delay in sowinge0
- Outcome
- seed yielde0
- Direction
- reducede0
- Value
- 309 kg/hae0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“oil concentration was reduced by 1.1 percentage points and seed yield by 309 kg/ha for every 2 weeks delay in sowing”
e1“canola ( Brassica napus )”
Claim · model-written summary
Delayed sowing reduced oil concentration more at Mullewa than at Mt Barker.
- Taxon
- canolaBrassica napus var. napuse1
- Treatment
- delayed sowinge0
- Outcome
- oil concentratione0
- Direction
- far greatere0
- Comparator
- Mt Barkere0
- Setting
- Mullewae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The magnitude of reduction in oil concentration from delayed sowing was far greater in a low rainfall site at Mullewa than in the high rainfall site at Mt Barker”
e1“canola ( Brassica napus )”
Claim · model-written summary
Later sowing shortened post-anthesis duration.
- Taxon
- canolaBrassica napus var. napuse1
- Treatment
- Later sowingse0
- Outcome
- post-anthesis duratione0
- Direction
- shortenede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Later sowings shortened post-anthesis duration”
e1“canola ( Brassica napus )”
Claim · model-written summary
With the same sowing date, early-flowering cultivars had longer post-anthesis duration.
- Taxon
- canolaBrassica napus var. napuse1
- Material
- early flowering cultivarse0
- Outcome
- post-anthesis duratione0
- Direction
- longere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“With a given sowing date, early flowering cultivars resulted in longer post-anthesis duration”
e1“canola ( Brassica napus )”
Claim · model-written summary
A 10-day longer post-anthesis period accompanied 1.2 percentage points higher oil concentration.
- Taxon
- canolaBrassica napus var. napuse1
- Organ / stage
- post-anthesise0
- Outcome
- Oil concentratione0
- Direction
- increasede0
- Value
- 1.2 percentage pointse0
- Qualifier
- 10-day increase in post-anthesis duratione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Oil concentration increased by 1.2 percentage points for a 10-day increase in post-anthesis duration”
e1“canola ( Brassica napus )”
Claim · model-written summary
Each additional 10 mm of post-anthesis rain accompanied 0.7 percentage points higher oil concentration.
- Taxon
- canolaBrassica napus var. napuse1
- Outcome
- oile0
- Direction
- increasee0
- Value
- 0.7 percentage pointse0
- Qualifier
- every 10-mm increase in post-anthesis rainfalle0
- Setting
- post-anthesis rainfalle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The rates of increase were 0.7 percentage points for oil and 116 kg/ha for seed yield for every 10-mm increase in post-anthesis rainfall”
e1“canola ( Brassica napus )”
Claim · model-written summary
Each additional 10 mm of post-anthesis rain accompanied 116 kg/ha greater seed yield.
- Taxon
- canolaBrassica napus var. napuse1
- Outcome
- seed yielde0
- Direction
- increasee0
- Value
- 116 kg/hae0
- Setting
- post-anthesis rainfalle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The rates of increase were 0.7 percentage points for oil and 116 kg/ha for seed yield for every 10-mm increase in post-anthesis rainfall”
e1“canola ( Brassica napus )”
Claim · model-written summary
Each 1°C increase in post-anthesis temperature accompanied 0.68 percentage points lower oil concentration.
- Taxon
- canolaBrassica napus var. napuse1
- Outcome
- oile0
- Direction
- reductione0
- Value
- 0.68 percentage pointse0
- Setting
- post-anthesis temperaturee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The rates of reduction were 0.68 percentage points for oil and 289 kg/ha for seed yield for every 1°C increase in post-anthesis temperature”
e1“canola ( Brassica napus )”
Claim · model-written summary
Each 1°C increase in post-anthesis temperature accompanied 289 kg/ha lower seed yield.
- Taxon
- canolaBrassica napus var. napuse1
- Outcome
- seed yielde0
- Direction
- reductione0
- Value
- 289 kg/hae0
- Setting
- post-anthesis temperaturee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The rates of reduction were 0.68 percentage points for oil and 289 kg/ha for seed yield for every 1°C increase in post-anthesis temperature”
e1“canola ( Brassica napus )”
Claim · model-written summary
The authors recommend early sowing with an early-flowering cultivar for high-yield, high-oil canola.
- Taxon
- canolaBrassica napus var. napuse0
- Outcome
- a combination of an early date of sowing with an early flowering cultivare0
- Setting
- lower rainfall arease0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a combination of an early date of sowing with an early flowering cultivar would be essential for the production of high yield and high oil canola in the lower rainfall areas”
Claim · model-written summary
Indian mustard tolerated high temperature and water deficit.
- Taxon
- Indian mustard
Brassica junceae0 - Outcome
- tolerance to high temperature and water deficite0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Indian mustard ( B. juncea ) showed tolerance to high temperature and water deficit”
Claim · model-written summary
Indian mustard’s low yield potential made early sowing uneconomical.
- Taxon
- Indian mustardBrassica junceae1
- Outcome
- low yield potentiale0
- Qualifier
- uneconomical with early sowinge0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the low yield potential makes it uneconomical with early sowing”
e1“Indian mustard ( B. juncea )”
Claim · model-written summary
The authors suggest yield improvement may depend on greater canola tolerance to heat and water deficit during seed growth.
- Taxon
- canolaBrassica napus var. napuse0
- Organ / stage
- seed growth and developmente0
- Outcome
- increased tolerance of canola to high temperature and water deficite0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Further improvement in seed yield could be dependent on increased tolerance of canola to high temperature and water deficit during seed growth and development”
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See all 71 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.