In recent years under the trends of rapid climate change, the earth’s average surface temperature is increasing, causing disruption in rainfall patterns and increased occurrence of extreme weather events. This has greatly threatened agricultural production and biodiversity. In view of the global warming may have effects on Taiwan’s rice production, COA has mobilized its affiliated institutes to undertake related research to come up with strategies and technologies to cope with the challenge.

    In response, TARI has assessed the sensitivity of prevailing rice cultivars to various temperatures, and found that higher temperatures during growth period would affect the production of paddy rice. The sensitivity varies among different paddy rice varieties. The tested paddy rice varieties will have the maximum yields, when the average temperature during the whole growing period is in the range of 22-24^oC. Increase in the average temperature of the whole growth period will result in decrease in yield. The rate of decrease in yield varies with the level of temperature increase. In general, when the temperature goes up by 1^oC, the yield would decrease by 2-8%; up by 2^oC, and the yield would decrease by 8-16%. At the more sensitive grain filling stage, the optimum temperatures are between 24.5 and 25.5^oC; increase in average temperatures would result in decrease in yields. In general, when the temperature goes up by 1^oC, the yield would reduce by 4-15%; up by 2^oC, and the yield would decrease by 9-36%. As to the effect of temperatures on rice quality, increase in average temperature at grain filling stage would reduce amylase content, and may also increase the proportion of crude protein, causing a reduction in the translucency of rice grain, and decrease in the percentage of head rice grains, thus diminish the quality and economic value of rice.

    The obtained results will serve as useful reference in choosing appropriate production sites and adjusting the planting dates for different superior rice varieties to cope with the global warming, and to ensure production of high-yielding and good quality rice crop for food security.