Since the introduction of japonica type rice in the 1920s, Taiwan has become the lowest latitude region that japonica type rice cultivars are dominantly cultivated. There are two rice cropping seasons annually in Taiwan, and temperature of these two seasons is higher than those of temperate countries such as Japan. With the concern of global warming trend, changes in temperature and grain quality in the major rice production zones of Taiwan were analyzed in this study. Results from database analysis indicated that temperature of the major rice production zones has increased in recent years (2000-2008), relative to the time period from 1990 to 1999. The increases of temperature were especially evident during grain filling stage in both crops. As for grain quality, generally the rate of immature chalky grains was higher in the 1st crop than that in the 2nd crop and might be attributed to the higher temperature during the grain filling of the 1st crop. Results further showed that cultivation timing has been shifted in recent years. Transplanting date has been moved forward in the 1st crop while was delayed in the 2nd crop in the major production zones, implying that farmers might have acknowledged the climate change and did it to adapt to global warming. The potential effects of the current warming trend on rice yield and quality traits are also discussed in the context.
High