| Project/Area Number |
11460006
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
作物学
|
|---|
| Research Institution | Hokkaido University |
|---|
Principal Investigator |
HASEGAWA Toshihiro Hokkaido Univ., Grad. School of Agric., Assoc. Prof., 大学院・農学研究科, 助教授 (10228455)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
TAKAMURE Itsuro Hokkaido Univ., Grad. School of Agric., Assist. Prof., 大学院・農学研究科, 助手 (90179557)
WANG Xiufeng Hokkaido Univ., Grad. School of Agric., Lec., 大学院・農学研究科, 講師 (30301873)
OSAKI Mitsuru Hokkaido Univ., Grad. School of Agric., Prof., 大学院・農学研究科, 教授 (60168903)
|
|---|
| Project Period (FY) |
1999 – 2001
|
| Project Status |
Completed (Fiscal Year 2001)
|
| Budget Amount *help |
¥14,600,000 (Direct Cost: ¥14,600,000)
Fiscal Year 2001: ¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 2000: ¥5,000,000 (Direct Cost: ¥5,000,000)
Fiscal Year 1999: ¥7,700,000 (Direct Cost: ¥7,700,000)
|
|---|
| Keywords | Biomass / Canopy radiation interception / Cool water temperature / Developmental stage / Oryza sativa L. / Simulation / Spikelet fertility / Yield / 水田水温 / 稔実歩合 / 水稲 / 子実収量 / 水温 / 日射利用効率 / 葉面積増加速度 / 蒸散速度 / 葉面積展開 / 根部冷却 / 相対含水率 / 根・葉面積比 |
|---|
| Research Abstract |
Water temperature (Tw) can limit rice yield via various growth processes. A simple simulation model was developed to evaluate the effects of Tw on rice growth and yield based on the field trials conducted under different Tw conditions (17-26℃). The model covers the effects of Tw on the developmental rate, leaf appearance, tillering and culm elongation. Leaf area estimates were derived from a product of leaf number on the main culm and tiller number. Radiation use efficiency was expressed as a function of developmental stage. Harvest index was determined as a function of spikelet fertility, which was estimated with the cooling degree-days based on either Tw or air temperature depending on the vertical position of the developing panicles. We tested the model at four locations (Pippu, Iwamizawa, Sapporo and Oono) in Hokkaido for 1990-1999. The estimated yields were generally in good agreement with the measured yields that ranged from 19 to 677 gm^<-2> with the root mean square deviation (RMSD) of 79gm^<-2> (n=33). The Tw estimation model based on the heat balance (Kuawgata et al. 2001) estimated those at the four locations with a RMSD of about 1℃ with no indicative trend in the residuals. Tw averaged for the past 10 years was estimated to be higher than Ta by 3.8℃ in Sapporo, the Tw difference being equivalent to about 300 gm^<-2> of grain yields indicating the marked "water blanket" effect on rice productivity in Hokkaido. The regional yield variation was largely attributed to solar radiation, but wind speed that affects Tw also had a significant effect. A simulation indicated that a rise in air temperature by 3℃ could result in a 1.3℃ increase in Tw and a 6 % increase in grain yield in Sapporo, if other climatic conditions were unchanged.
|
