Abstract
Increased grain yield in response to high rates of application of nitrogen (N) fertiliser is often limited by increased spikelet sterility, particularly under low temperature conditions in the New South Wales (NSW) rice industry. In 3 field experiments, different N rates were applied for different sowing dates to investigate the interaction between N rate and temperature during microspore development on spikelet sterility and grain yield. In one experiment the effect of water depth on spikelet sterility was also investigated. Engorged pollen production, spikelet sterility, and yield and its components were recorded. Application of N affected a few different processes that lead into spikelet sterility. Application of N at both pre-flood (PF) and panicle initiation (PI) significantly reduced the number of engorged pollen grains per anther, which was negatively correlated with spikelet sterility. Application of N and low temperature during microspore development with the absence of deep water also decreased pollen engorgement efficiency (the percentage of pollen grains that were engorged). Application of N further increased spikelet density, which, in turn, increased both spikelet sterility and grain yield. The combined effect of spikelet density and low temperature during microspore development explained the 44% of variation in the number of engorged pollen grains per anther. Grain yield was decreased by low temperature during microspore development in the shallow water when N was applied. Spikelet sterility as a result of late sowing was strongly correlated with minimum temperature during flowering. It is concluded that N application reduced pollen number per anther as a result of increased spikelet density, and this made the spikelets more susceptible to low temperature, causing increased spikelet sterility.
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Claims 11
Claim · model-written summary
Nitrogen at pre-flood reduced engorged pollen grains per anther.
- Taxon
- rice
Oryza sativat0 - Treatment
- N at both pre-flood (PF) and panicle initiation (PI)e0
- Outcome
- number of engorged pollen grains per anthere0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Application of N at both pre-flood (PF) and panicle initiation (PI) significantly reduced the number of engorged pollen grains per anther”
t0“rice”
Claim · model-written summary
Engorged pollen grains per anther were negatively correlated with spikelet sterility.
- Taxon
- riceOryza sativat0
- Organ / stage
- engorged pollen grains per anthere0
- Outcome
- spikelet sterilitye0
- Direction
- negatively correlatede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the number of engorged pollen grains per anther, which was negatively correlated with spikelet sterility”
t0“rice”
Claim · model-written summary
Nitrogen and low temperature without deep water decreased pollen engorgement efficiency.
- Taxon
- riceOryza sativat0
- Treatment
- Application of N and low temperature during microspore development with the absence of deep watere0
- Outcome
- pollen engorgement efficiencye0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Application of N and low temperature during microspore development with the absence of deep water also decreased pollen engorgement efficiency”
t0“rice”
Claim · model-written summary
Nitrogen increased spikelet density.
- Taxon
- riceOryza sativat0
- Treatment
- Application of Ne0
- Outcome
- spikelet densitye0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Application of N further increased spikelet density”
t0“rice”
Claim · model-written summary
Increased spikelet density increased spikelet sterility.
- Taxon
- riceOryza sativat0
- Organ / stage
- spikelet densitye0
- Outcome
- spikelet sterilitye0
- Direction
- increasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“increased spikelet density, which, in turn, increased both spikelet sterility and grain yield”
t0“rice”
Claim · model-written summary
Increased spikelet density increased grain yield.
- Taxon
- riceOryza sativat0
- Organ / stage
- spikelet densitye0
- Outcome
- grain yielde0
- Direction
- increasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“increased spikelet density, which, in turn, increased both spikelet sterility and grain yield”
t0“rice”
Claim · model-written summary
Spikelet density and low temperature explained 44% of variation in engorged pollen grains per anther.
- Taxon
- riceOryza sativat0
- Treatment
- low temperature during microspore developmente0
- Outcome
- variation in the number of engorged pollen grains per anthere0
- Value
- 44%e0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The combined effect of spikelet density and low temperature during microspore development explained the 44% of variation in the number of engorged pollen grains per anther”
t0“rice”
Claim · model-written summary
Low temperature decreased yield in shallow water when nitrogen was applied.
- Taxon
- riceOryza sativat0
- Treatment
- low temperature during microspore developmente0
- Outcome
- Grain yielde0
- Direction
- decreasede0
- Qualifier
- shallow water when N was appliede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Grain yield was decreased by low temperature during microspore development in the shallow water when N was applied”
t0“rice”
Claim · model-written summary
Sterility after late sowing correlated strongly with minimum flowering temperature.
- Taxon
- riceOryza sativat0
- Treatment
- late sowinge0
- Outcome
- Spikelet sterilitye0
- Qualifier
- minimum temperature during floweringe0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Spikelet sterility as a result of late sowing was strongly correlated with minimum temperature during flowering”
t0“rice”
Claim · model-written summary
Authors conclude nitrogen reduced pollen number through increased spikelet density.
- Taxon
- riceOryza sativat0
- Treatment
- N applicatione0
- Outcome
- pollen number per anthere0
- Direction
- reducede0
- Qualifier
- increased spikelet densitye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“N application reduced pollen number per anther as a result of increased spikelet density”
t0“rice”
Claim · model-written summary
Authors conclude reduced pollen made spikelets more susceptible to low temperature and increased sterility.
- Taxon
- riceOryza sativat0
- Outcome
- spikelet sterilitye0
- Direction
- increasede0
- Qualifier
- more susceptible to low temperaturee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“this made the spikelets more susceptible to low temperature, causing increased spikelet sterility”
t0“rice”
The same questions in other papers
cold · yield · Oryza sativa (rice)Results differ
42 papers in the same direction as this paper · 20 in the opposite direction
- no effect
- positive
- positive
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See all 63 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.