无产阶级文化大革命以来,上海郊区一年三熟制的面积不断扩大,后季稻的产量有了较大幅度的增长。但由于一年三熟的作物生长季节长,熟熟高产需要有个较长的大田生长期。而每年气象条件有变化,季节早晚也不一,致使有些年份双季稻的大田生长期较短,季节 Since the Great Proletarian Cultural Revolution, the area of ​​three-year-olds in the suburbs of Shanghai has been constantly expanding and the output of the latter-season rice has been greatly increased. However, due to the season of crop growth in three crops a year, mature and high-yielding needs a longer field growth period. The annual weather conditions have changed, the season sooner or later, resulting in some years of double cropping paddy field growth period is shorter, the season