译 名：
Analysis or Meteorology for Seed Production and Multiplication of "Two-Line" Hybrid Rice in Changsha Region
作 者：
Long Guobing (Changsha Agrometeorological Station )
关键词：
critical light duration, critical temperature, hours of light duration, light intensity, safe full heading stage.
摘 要：
It is appropriate in Changsha to grow sterile lines of photoperiod.thermal type whose fertility changes when the critical light duration is longer than 13hr and 20 minutes and the critical temperature is as high as the daily mean temperature in successive 4 days is higher than 24 , or the daily mean temperature in successive2 days is higher than 23 , or the daily lowest temperature in successive 4 days is higher than 22 , or the daily lowest temperature in successive 3 days is higher than 21 . If seed production is conducted. it is better then the sensitive stage is in middle August and the heading stage is in late August or early September. If multiplication is done. it is better when the sensitive stage is in late August or early September and the heading stage is in early or middle September.
