早春,随着气温逐渐回升,小麦由越冬休眠状态慢慢开始恢复生长,当心叶变绿,新生叶片伸长1一2厘米时,麦苗就进入返青期。在华北北部地区麦苗一般是2月底或3月上旬开始返青。 返青期麦苗要滋生新的分蘖,生长新的叶片和次生根,这个时期的气象条件和管理措施对小麦分蘖数的多少、中部茎生叶片的大小和 Early spring, with the gradual rise in temperature, the wheat began to recover from the winter dormancy recovery slowly, be careful green leaves, new leaf elongation 1 to 2 cm, the wheat seedling into the greening period. In northern North China wheat seedlings are generally back to the end of February or early March. Greening wheat seedlings to breed new tillers, the growth of new leaves and secondary roots, the meteorological conditions of this period and management measures on the number of tillers of wheat, the size of the central stem leaves and