一、适期播种的意义及其确定的主要方法:冬小麦适期播种是夺取丰收的重要一环。播种过早,发生旺长、苗不壮,入冬后易受冻害;播种过晚,冬前苗弱、分蘖不足,发育不良、越冬期抗逆性差,造成减产。适期播种,利于个体发育,增加有效分蘖,达到苗全苗壮,安全越冬,是获得高产稳产的基础。在气候和地墒正常的情况下,冬小麦从播种到出苗,约需100℃的积温(积温 First, the significance of sowing and its main method of determining the appropriate: Winter wheat sowing is an important part of seizing good harvest. Sowing too early, the occurrence of prosperous, seedling is not strong, vulnerable to frost damage after winter; sown too late, weak before winter, tillering inadequate, dysplasia, overwintering resistance is poor, resulting in reduced production. Sowing the right, conducive to individual development, increase effective tillering, seedlings to achieve full seedling strong, safe and wintering, is to obtain high and stable yield basis. In the normal climate and moisture conditions, winter wheat from sowing to emergence, about 100 ℃ accumulated temperature (accumulated temperature