早春麦田半数以上的麦苗心叶(春生第一叶)长出部分达到1—2厘米时,称为“返青”。从返青开始到起身之前,历时约一个月,属苗期阶段的最后一个时期,称返青期。这个时期的生长主要是生根、长叶和分蘖。这是促使晚弱苗升级、控制旺苗徒长、调节群体大小和决定成穗率高低的关键时期。所以返青期的管理方向是科学分类指导,加强镇压划锄,控旺苗稳长保蘖,促弱苗早发稳长,长根增蘖,巩固冬前分蘖,控制无效分 More than half of the early spring wheat field heart of young leaves (spring first leaf) to grow part of 1-2 cm, known as the “green”. From turning green until it got up, it lasted about one month, belonging to the last stage of the seedling stage and called the returning to youth. The growth of this period is mainly rooting, long leaves and tillering. This is to promote the late weak seedlings to upgrade, control the growth and prosperity, adjust the size of the group and determine the rate of high and low into a crucial period. Therefore, the management direction of returning to green is scientific guidance, to strengthen the suppression of hoeing, Wang governance seedlings stable tillering, weak seedling early onset of stability, long root tillering, consolidation of winter tillering, invalid control points