Abstract
Production of flooded direct-seeded rice ( Oryza sativa L.) in semi-arid tropical regions of northern Australia would be enhanced by increasing the efficiency of fertiliser nitrogen (N) use. Short-statured and early-maturing genotypes have replaced the taller and later genotypes in northern Australia, and they may respond differently to N. This paper reports the results of 4 experiments comparing the response of 3 rice genotypes differing in maturity and stature to 5 rates of applied nitrogen (0, 70, 140, 210, and 280 kg/ha) over 4 seasons (2 wet and 2 dry seasons) in the Burdekin River Irrigation Area, northern Australia. Grain yield varied among seasons and was negatively correlated with average daily mean temperature during the 30-day period before anthesis. The response of yield to N fertilisation was generally higher in the dry season. Panicle number was correlated with grain yield in both seasons, yet responded to N fertilisation only in the dry season. In 3 of 4 experiments, grain yield responded to the application of up to 70 kg N/ha, yielding about 750 g/m2. In only 1 dry season experiment did grain yield respond to the application of 140 kg N/ha, yielding about 930 g/m2. In this experiment, the response of grain yield to N rate also varied among genotypes such that yield in the early-maturing genotypes (Newbonnet and Lemont) was more responsive to N rates above 70 kg/ha than in the late-maturing genotype (Starbonnet). Of the 3 genotypes examined, highest yields were attained in Newbonnet (early-maturing, medium-statured) by combining high total dry matter production with high harvest index, indicating that this plant type may have an advantage in northern Australia. Yields in Lemont (early-maturing, short-statured) and Starbonnet (late-maturing, tall-statured) were limited by dry matter production and harvest index, respectively. There is some evidence that increased dry matter production in Newbonnet compared with Lemont was related to increased stem length. The evidence linking high harvest index with increased earliness in Newbonnet compared with Starbonnet is less compelling.
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Claims 13
Claim · model-written summary
Grain yield varied by season.
- Taxon
- rice
Oryza sativat0 - Outcome
- Grain yielde0
- Direction
- variede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Grain yield varied among seasons”
t0“rice”
Claim · model-written summary
Grain yield was negatively correlated with preanthesis mean temperature.
- Taxon
- riceOryza sativat0
- Treatment
- average daily mean temperaturee0
- Outcome
- Grain yielde0
- Direction
- negatively correlatede0
- Qualifier
- during the 30-day period before anthesise0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Grain yield varied among seasons and was negatively correlated with average daily mean temperature during the 30-day period before anthesis”
t0“rice”
Claim · model-written summary
Yield response to nitrogen was generally higher in the dry season.
- Taxon
- riceOryza sativat0
- Treatment
- N fertilisatione0
- Outcome
- response of yielde0
- Direction
- highere0
- Setting
- dry seasone0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The response of yield to N fertilisation was generally higher in the dry season”
t0“rice”
Claim · model-written summary
Panicle number correlated with grain yield in both seasons.
- Taxon
- riceOryza sativat0
- Organ / stage
- Paniclee0
- Outcome
- Panicle numbere0
- Qualifier
- grain yield in both seasonse0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Panicle number was correlated with grain yield in both seasons”
t0“rice”
Claim · model-written summary
Panicle number responded to nitrogen only in the dry season.
- Taxon
- riceOryza sativat0
- Treatment
- N fertilisatione0
- Outcome
- Panicle numbere0
- Setting
- dry seasone0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Panicle number was correlated with grain yield in both seasons, yet responded to N fertilisation only in the dry season”
t0“rice”
Claim · model-written summary
In three experiments, grain yield responded up to 70 kg N/ha, reaching about 750 g/m2.
- Taxon
- riceOryza sativat0
- Treatment
- up to 70 kg N/hae0
- Outcome
- grain yielde0
- Value
- 750 g/m2e0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In 3 of 4 experiments, grain yield responded to the application of up to 70 kg N/ha, yielding about 750 g/m2”
t0“rice”
Claim · model-written summary
In one dry season experiment grain yield responded up to 140 kg N/ha, reaching about 930 g/m2.
- Taxon
- riceOryza sativat0
- Treatment
- 140 kg N/hae0
- Outcome
- grain yielde0
- Value
- 930 g/m2e0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In only 1 dry season experiment did grain yield respond to the application of 140 kg N/ha, yielding about 930 g/m2”
t0“rice”
Claim · model-written summary
Newbonnet and Lemont yield responded more to nitrogen above 70 kg/ha than Starbonnet.
- Taxon
- riceOryza sativat0
- Material
- Newbonnet and Lemonte0
- Treatment
- N rates above 70 kg/hae0
- Outcome
- yielde0
- Direction
- more responsivee0
- Comparator
- Starbonnete0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“yield in the early-maturing genotypes (Newbonnet and Lemont) was more responsive to N rates above 70 kg/ha than in the late-maturing genotype (Starbonnet)”
t0“rice”
Claim · model-written summary
Newbonnet attained the highest yield among the three genotypes.
- Taxon
- riceOryza sativat0
- Material
- Newbonnete0
- Outcome
- yieldse0
- Direction
- higheste0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“highest yields were attained in Newbonnet”
t0“rice”
Claim · model-written summary
Lemont yield was limited by dry matter production.
- Taxon
- riceOryza sativat0
- Material
- Lemonte0
- Organ / stage
- early-maturinge0
- Outcome
- Yieldse0
- Direction
- limitede0
- Qualifier
- dry matter productione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Yields in Lemont (early-maturing, short-statured) and Starbonnet (late-maturing, tall-statured) were limited by dry matter production and harvest index, respectively”
t0“rice”
Claim · model-written summary
Starbonnet yield was limited by harvest index.
- Taxon
- riceOryza sativat0
- Material
- Starbonnete0
- Outcome
- Yieldse0
- Direction
- limitede0
- Qualifier
- harvest indexe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Yields in Lemont (early-maturing, short-statured) and Starbonnet (late-maturing, tall-statured) were limited by dry matter production and harvest index, respectively”
t0“rice”
Claim · model-written summary
Newbonnet dry matter production was greater than Lemont and may relate to stem length.
- Taxon
- riceOryza sativat0
- Material
- Newbonnete0
- Organ / stage
- stem lengthe0
- Outcome
- dry matter productione0
- Direction
- increasede0
- Comparator
- Lemonte0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“increased dry matter production in Newbonnet compared with Lemont was related to increased stem length”
t0“rice”
Claim · model-written summary
Evidence connecting Newbonnet high harvest index with earlier maturity than Starbonnet was less compelling.
- Taxon
- riceOryza sativat0
- Material
- Newbonnete0
- Outcome
- harvest indexe0
- Direction
- highe0
- Qualifier
- less compellinge0
- Comparator
- Starbonnete0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The evidence linking high harvest index with increased earliness in Newbonnet compared with Starbonnet is less compelling”
t0“rice”
The same questions in other papers
nitrogen · yield · Oryza sativa (rice)Positive and negative results
1,802 papers in the same direction as this paper · 193 in the opposite direction · 49 reporting no difference from an alternative
- no effect
- positive
- negative
2,041 papers more in this group
See all 2,045 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.