High temperatures during the grain-filling period do not reduce the potential grain dry matter increase of rice

Toru Kobata, Naoya Uemuki

Research output: Contribution to journalArticle

61 Citations (Scopus)

Abstract

High temperatures during the grain-filling period (GFP) of rice (Oryza saliva L.) increase the grain dry matter increase rate (GIR), but this increase in GIR is insufficient to completely compensate for the concomitant reduced GFP, and as a result, grain yield decreases. The shortfall in GIR as temperatures increase has been believed to signify a reduction of the potential GIR as a sink capacity. However, we suspect that lack of assimilate supply to the grain, rather than the decreased potential GIR, lowers the GIR and causes reduced grain weight. Our objective was to determine if the grain weight could reach full potential under higher temperature conditions if assimilate supply during the GFP was sufficient to sustain the increased GIR. Rice was grown at three locations in western Japan over 3 yr. At one location, plots were covered with plastic film during the GFP to increase temperature. Spikelet filling percentages (F%) at maturity varied between 70 and 90% when mean temperatures ranged between 23 and 29°C during the GFP. When plots were thinned to half density during GFP, all F% were approximated by a single logistic equation based on accumulated temperature, with a ceiling of 90%. Hence, thinning can overcome the lower F%. These results suggest that potential GIR in rice is not reduced by high temperatures during the GFP. Yield reductions commonly associated with such conditions are likely due to the failure of assimilate supply to the grain to meet the requirements of the accelerated GIR.

Original languageEnglish
Pages (from-to)406-414
Number of pages9
JournalAgronomy Journal
Volume96
Issue number2
Publication statusPublished - May 1 2004
Externally publishedYes

Fingerprint

filling period
rice
temperature
plastic film
Oryza
saliva
heat sums
thinning (plants)
inflorescences
grain yield

ASJC Scopus subject areas

  • Agronomy and Crop Science

Cite this

High temperatures during the grain-filling period do not reduce the potential grain dry matter increase of rice. / Kobata, Toru; Uemuki, Naoya.

In: Agronomy Journal, Vol. 96, No. 2, 01.05.2004, p. 406-414.

Research output: Contribution to journalArticle

@article{b9f38cb4c5094a41aa2d4b3c5d820339,
title = "High temperatures during the grain-filling period do not reduce the potential grain dry matter increase of rice",
abstract = "High temperatures during the grain-filling period (GFP) of rice (Oryza saliva L.) increase the grain dry matter increase rate (GIR), but this increase in GIR is insufficient to completely compensate for the concomitant reduced GFP, and as a result, grain yield decreases. The shortfall in GIR as temperatures increase has been believed to signify a reduction of the potential GIR as a sink capacity. However, we suspect that lack of assimilate supply to the grain, rather than the decreased potential GIR, lowers the GIR and causes reduced grain weight. Our objective was to determine if the grain weight could reach full potential under higher temperature conditions if assimilate supply during the GFP was sufficient to sustain the increased GIR. Rice was grown at three locations in western Japan over 3 yr. At one location, plots were covered with plastic film during the GFP to increase temperature. Spikelet filling percentages (F{\%}) at maturity varied between 70 and 90{\%} when mean temperatures ranged between 23 and 29°C during the GFP. When plots were thinned to half density during GFP, all F{\%} were approximated by a single logistic equation based on accumulated temperature, with a ceiling of 90{\%}. Hence, thinning can overcome the lower F{\%}. These results suggest that potential GIR in rice is not reduced by high temperatures during the GFP. Yield reductions commonly associated with such conditions are likely due to the failure of assimilate supply to the grain to meet the requirements of the accelerated GIR.",
author = "Toru Kobata and Naoya Uemuki",
year = "2004",
month = "5",
day = "1",
language = "English",
volume = "96",
pages = "406--414",
journal = "Agronomy Journal",
issn = "0002-1962",
publisher = "American Society of Agronomy",
number = "2",

}

TY - JOUR

T1 - High temperatures during the grain-filling period do not reduce the potential grain dry matter increase of rice

AU - Kobata, Toru

AU - Uemuki, Naoya

PY - 2004/5/1

Y1 - 2004/5/1

N2 - High temperatures during the grain-filling period (GFP) of rice (Oryza saliva L.) increase the grain dry matter increase rate (GIR), but this increase in GIR is insufficient to completely compensate for the concomitant reduced GFP, and as a result, grain yield decreases. The shortfall in GIR as temperatures increase has been believed to signify a reduction of the potential GIR as a sink capacity. However, we suspect that lack of assimilate supply to the grain, rather than the decreased potential GIR, lowers the GIR and causes reduced grain weight. Our objective was to determine if the grain weight could reach full potential under higher temperature conditions if assimilate supply during the GFP was sufficient to sustain the increased GIR. Rice was grown at three locations in western Japan over 3 yr. At one location, plots were covered with plastic film during the GFP to increase temperature. Spikelet filling percentages (F%) at maturity varied between 70 and 90% when mean temperatures ranged between 23 and 29°C during the GFP. When plots were thinned to half density during GFP, all F% were approximated by a single logistic equation based on accumulated temperature, with a ceiling of 90%. Hence, thinning can overcome the lower F%. These results suggest that potential GIR in rice is not reduced by high temperatures during the GFP. Yield reductions commonly associated with such conditions are likely due to the failure of assimilate supply to the grain to meet the requirements of the accelerated GIR.

AB - High temperatures during the grain-filling period (GFP) of rice (Oryza saliva L.) increase the grain dry matter increase rate (GIR), but this increase in GIR is insufficient to completely compensate for the concomitant reduced GFP, and as a result, grain yield decreases. The shortfall in GIR as temperatures increase has been believed to signify a reduction of the potential GIR as a sink capacity. However, we suspect that lack of assimilate supply to the grain, rather than the decreased potential GIR, lowers the GIR and causes reduced grain weight. Our objective was to determine if the grain weight could reach full potential under higher temperature conditions if assimilate supply during the GFP was sufficient to sustain the increased GIR. Rice was grown at three locations in western Japan over 3 yr. At one location, plots were covered with plastic film during the GFP to increase temperature. Spikelet filling percentages (F%) at maturity varied between 70 and 90% when mean temperatures ranged between 23 and 29°C during the GFP. When plots were thinned to half density during GFP, all F% were approximated by a single logistic equation based on accumulated temperature, with a ceiling of 90%. Hence, thinning can overcome the lower F%. These results suggest that potential GIR in rice is not reduced by high temperatures during the GFP. Yield reductions commonly associated with such conditions are likely due to the failure of assimilate supply to the grain to meet the requirements of the accelerated GIR.

UR - http://www.scopus.com/inward/record.url?scp=1642271212&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=1642271212&partnerID=8YFLogxK

M3 - Article

VL - 96

SP - 406

EP - 414

JO - Agronomy Journal

JF - Agronomy Journal

SN - 0002-1962

IS - 2

ER -