1998～ 1999年太和县小麦苗期干旱高温 ,使年前有效分蘖减少 ,穗数降低 ,翌年早春低温又冻死低位分蘖。但由于中后期雨水充足 ,温度适宜 ,小麦开花期提前 ,光合率提高 ,使得千粒重、穗粒数增加 ,产量与前 3a平均产量持平。在千粒重 40g以下的地块 ,不实小穗数和结实小穗数的比值与经济系数负相关 During the period from 1998 to 1999, wheat seedlings in Taihe County suffered from drought and high temperature, which reduced the effective tillers and the number of spikelets in the year before. However, due to adequate rainfall in the mid-late, appropriate temperature, early flowering wheat, photosynthetic rate increased, making the 1000-grain weight, grain number increased, the average yield and the previous 3a flat. In the land below 40g weight, the ratio of false spikelets to strong spikelets was negatively correlated with economic coefficient