Abstract
Response of grain yield and milled-rice protein content to nitrogen topdress (N) timing at panicle initiation stage (PIS) is critical for quantifying real-time N requirement for target grain yield and milled-rice protein content. Two split-split-plot experiments with three replications, one in 2004 and the other in 2005, were conducted in Experimental Farm, Seoul National University, Suwon, Korea. The experiments included three N rates at tillering stage (TS), three N timing treatments at panicle initiation stage (PIS) and two rice cultivars. The N rates at TS, N timing at PIS, and rice cultivars were randomly assigned to main plot, sub plot, and sub-sub plot, respectively. Results showed that the delayed N application at PIS reduced grain yield in 2004 and increased milled-rice protein content in both years significantly at 0.05 probability level. The calculated optimum N timing at PIS from pooled data by N rates and rice cultivars in two years was at 28 days before heading (DBH). However, real-time of N timing at PIS was dependent on plant growth and N status around PIS that in turn was dependent on applied N rates at TS. The optimum N timing at PIS was at 30 DBH for no N treatments at TS while at 27 DBH for 3.6 and 7.2 ㎏ N/10a treatments and at 27 and 29 DBH for Hwaseongbyeo and Daeanbyeo, respectively. In general, earlier applied N at PIS resulted in lower milled-rice protein content but the highest grain yield was expected to be obtained when N topdress at PIS was applied at the time when shoot N concentration started to drop below about 23 ㎎/g due to dilution effect after transplanting. In conclusion, the results of our experiments imply that the currently recommended N topdress time (24DBH) at PIS in Korea should be reconsidered for the higher grain yield and the better quality of rice.
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Claims 10
Claim · model-written summary
Delayed nitrogen topdress at panicle initiation reduced rice grain yield in 2004 (significant at 0.05).
- Taxon
- rice
Oryza sativat0 - Treatment
- delayed N application at PISe0
- Outcome
- grain yielde0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“stage of rice”
e0“delayed N application at PIS reduced grain yield in 2004 and increased milled-rice protein content in both years significantly at 0.05 probability level”
Claim · model-written summary
Delayed nitrogen topdress at panicle initiation increased milled-rice protein content in both years (significant at 0.05).
- Taxon
- riceOryza sativat0
- Treatment
- delayed N application at PISe0
- Outcome
- milled-rice protein contente0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“stage of rice”
e0“delayed N application at PIS reduced grain yield in 2004 and increased milled-rice protein content in both years significantly at 0.05 probability level”
Claim · model-written summary
The optimum nitrogen topdress timing at panicle initiation from pooled data was 28 days before heading.
- Taxon
- riceOryza sativat0
- Outcome
- optimum N timing at PISe0
- Value
- 28 days before headinge0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“stage of rice”
e0“The calculated optimum N timing at PIS from pooled data by N rates and rice cultivars in two years was at 28 days before heading (DBH)”
Claim · model-written summary
The optimum topdress timing at panicle initiation was 30 days before heading when no nitrogen was applied at tillering.
- Taxon
- riceOryza sativat0
- Treatment
- no N treatments at TSe0
- Outcome
- optimum N timing at PISe0
- Value
- 30 DBHe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“stage of rice”
e0“The optimum N timing at PIS was at 30 DBH for no N treatments at TS while at 27 DBH for 3.6 and 7.2 ㎏ N/10a treatments and at 27 and 29 DBH for Hwaseongbyeo and Daeanbyeo, respectively”
Claim · model-written summary
The optimum topdress timing at panicle initiation was 27 days before heading for 3.6 and 7.2 kg N/10a at tillering.
- Taxon
- riceOryza sativat0
- Treatment
- 3.6 and 7.2 ㎏ N/10a treatmentse0
- Outcome
- optimum N timing at PISe0
- Value
- 27 DBHe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“stage of rice”
e0“The optimum N timing at PIS was at 30 DBH for no N treatments at TS while at 27 DBH for 3.6 and 7.2 ㎏ N/10a treatments and at 27 and 29 DBH for Hwaseongbyeo and Daeanbyeo, respectively”
Claim · model-written summary
The optimum topdress timing at panicle initiation for cultivar Hwaseongbyeo was 27 days before heading.
- Taxon
- riceOryza sativat0
- Material
- Hwaseongbyeoe0
- Outcome
- optimum N timing at PISe0
- Value
- 27e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“stage of rice”
e0“The optimum N timing at PIS was at 30 DBH for no N treatments at TS while at 27 DBH for 3.6 and 7.2 ㎏ N/10a treatments and at 27 and 29 DBH for Hwaseongbyeo and Daeanbyeo, respectively”
Claim · model-written summary
The optimum topdress timing at panicle initiation for cultivar Daeanbyeo was 29 days before heading.
- Taxon
- riceOryza sativat0
- Material
- Daeanbyeoe0
- Outcome
- optimum N timing at PISe0
- Value
- 29e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“stage of rice”
e0“The optimum N timing at PIS was at 30 DBH for no N treatments at TS while at 27 DBH for 3.6 and 7.2 ㎏ N/10a treatments and at 27 and 29 DBH for Hwaseongbyeo and Daeanbyeo, respectively”
Claim · model-written summary
Earlier nitrogen topdress at panicle initiation generally resulted in lower milled-rice protein content.
- Taxon
- riceOryza sativat0
- Treatment
- earlier applied N at PISe0
- Outcome
- milled-rice protein contente0
- Direction
- lowere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“stage of rice”
e0“earlier applied N at PIS resulted in lower milled-rice protein content”
Claim · model-written summary
The highest grain yield was expected when topdress at panicle initiation was applied as shoot N concentration started to drop below about 23 mg/g.
- Taxon
- riceOryza sativat0
- Treatment
- N topdress at PISe0
- Outcome
- grain yielde0
- Direction
- higheste0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“stage of rice”
e0“the highest grain yield was expected to be obtained when N topdress at PIS was applied at the time when shoot N concentration started to drop below about 23 ㎎/g”
Claim · model-written summary
The authors conclude that the currently recommended topdress time (24 days before heading) at panicle initiation in Korea should be reconsidered for higher grain yield and better rice quality.
- Taxon
- riceOryza sativae0
- Outcome
- currently recommended N topdress time (24DBH) at PISe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the currently recommended N topdress time (24DBH) at PIS in Korea should be reconsidered for the higher grain yield and the better quality of rice”
The same questions in other papers
nitrogen · yield · Oryza sativa (rice)Positive and negative results
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