2.2 Historical climate data collection and analysis
The 10-year air-temperature data (2011~2020) in Leizhou
was collected from the Tianqi Database
(http://lishi.tianqi.com/leizhou/index.html,
in Chinese). The air-temperature data included the daily minimum and
maximum temperatures (Table S2). The average of the minimum and maximum
temperatures was defined as the daily average air-temperature. Also, the
10-year daylength data (2006~2015) was collected from
the BMCX website
(https://richurimo.51240.com/leigaozhen__richurimo/,
in Chinese). The daylength data included the daily time of sunrise and
sunset (Table S3). The differences between the time of sunrise and
sunset were defined as the daylengths.
In addition, the WR growth period was artificially divided into four
stages, corresponding to different rice growth phases: seedling (S),
tillering (T), flowering (F), and ripening (R). The average values of
each year in the ten years were used to estimate differences in
air-temperatures and daylengths between the early and late
rice-cultivation seasons at different stages.