**3.1.1 Measurements of panicle temperature and weather**

We measured panicle and leaf temperatures every hour between 0600 and 1200 on the flower opening days (Table 5), using infrared thermography (Neo Thermo TVS-700, Nippon Avionics co. LTD., Tokyo, Japan) with a fixed emissivity factor of l. Weather factors (solar radiation, air temperature, relative humidity, and wind speed) were measured every 5 min using a wireless weather station (Wireless Vantage Pro, Davis Instruments, Hayward, CA, USA) located at Shimane University. Measurement details and calculating weather factors are the same in Experiment 1.
