Evaluation of yield and growth responses on paddy rice under the extremely high temperature using temperature gradient field chamber
2018
Oh, D., Chonnam National University, Gwangju, Republic of Korea | Ryu, J.H., Chonnam National University, Gwangju, Republic of Korea | Cho, Y., Chonnam National University, Gwangju, Republic of Korea | Kim, W., National Agriculture and Food Research Organization, Kannondai, Japan | Cho, J., Chonnam National University, Gwangju, Republic of Korea
The effect of elevated temperature on temperate paddy rice will be significant for dependable food supply in East Asia. Using temperature gradient field chamber (TGFC), which was designed to make the horizontal air temperature gradient by 0℃ to 3℃ higher than outside, we examined the measurement to understand the effects of extremely high temperature on paddy rice. In particular, the data of the year 2016, the worst heat wave in over 22 years, was analyzed in this study. The rice height in the relatively warmed condition was rapidly increased during early growth stage. However, the average grain weight and number of spikelet per panicle in the warmed chamber condition were gradually declined with increasing air temperature averaged for 40 days after first heading in each chamber. In particular, the grain yield was more dramatically decreased by the raising temperature because the percent ripened grain was quickly dropped as getting over the threshold temperature for pollination. Therefore, the surplus photosynthetic product by such lower grain filling rate may disturbed the decreases of the NDVI (Normalized Difference Vegetation Index) and SPAD chlorophyll values after first (normal) heading. In addition, the late-emerging head grain were appeared. However, this yield was too small to recover the normal yields decreased by extremely high temperature condition. Our result represented that the warmed condition in 2016 would be the critical limit for the stable yield of temperate paddy rice.
显示更多 [+] 显示较少 [-]