Effects of Elevated Air Temperature on Yield and Yield Components of Rice

서지정보

· 발행기관 : 한국농림기상학회
· 수록지 정보 : 한국농림기상학회지 / 17권 / 2호 / 156 ~ 164페이지
· 저자명 : 이규종, 뉴안덕, 최덕환, 반호영, 이변우

초록

High temperature stress would affect rice production in the future as heat wave is expected to occur frequently under climate change conditions. The objective of this study was to obtain rudimentary information to assess the impact of heat stress on rice yield and its yield component in Korea. Two rice cultivars “Hwaseongbyeo” (Japonica) and “Dasanbyeo” (Tongil-type) were grown at different nitrogen fertilization levels in two seasons. These cultivars were grown in 1/5000a Wagner pot placed within four plastic houses where temperature was controlled at ambient, ambient+1.5oC, ambient+3oC and ambient+5oC throughout the rice growing season in Suwon (37o16'N, 128o59'E), Korea. The degree of temperature change affected grain yield whereas the level of nitrogen had little impact on grain yield. The number of panicle per pot and spikelet per panicle were not significantly different among temperature treatments in both cultivars tested. In contrast, 1000-grain weight and ripened grain ratio were decreased significantly under the treatments raising the air temperature to the level of 5.0oC and 1.5oC above the ambient air temperature in Dasanbyeo and Hwaseongbyeo, respectively. Reduction of 1000?grain weight and ripened grain ratio under the temperature treatments of 3.0oC and 5.0oC above the ambient air temperature resulted in significantly less grain yield for Dasanbyeo and Hwaseongbyeo, respectively. The greater sensitivity of grain yield to temperature increase in Dasanbyeo was attributable to the sharp decrease of 1000-grain weight and ripened grain ratio with the temperature rise above 23oC during ripening period. On the other hand, Hwaseongbyeo had little variation of them in the temperature range of 23-27oC. These results suggested that grain yield would decrease under future climate conditions due to grain weight decreased by shorter grain filling period as well as the ripened grain ratio reduced by spikelet sterility and early abortion of rice kernel development. Thus, it would be essential to use cultivars tolerant to heat stress for climate change adaptation, which merits further studies for developing varieties that have traits to avoid spikelet sterility and early abortion of rice kernel, e.g., early morning flowering, under heat wave.

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