我国长江中下游双季稻区,由于茬口限制,双季晚稻早播迟插秧龄长,育龄期间又值夏季高温,秧苗生长迅速,移栽时苗体过大,秧苗素质不佳,栽后易败苗,不利早发争蘖,延缓季节,影响产量。农学家常用控水节肥等措施抑制秧苗徒长;作物生理学家则试图以化学调控技术缓解上述矛盾,十多年来曾试用了NAA、MH、CEPA、Kenbyo Due to the stubble limitation, the double cropping late rice early sowing late planting age, fertility during summer high temperature, rapid growth of seedlings, transplanting seedling body is too large, poor quality of seedlings, planted after the easy Defeat seedlings, adverse early tillering, delay the season, affecting the yield. Agronomists often use water and fertilizer to restrain the growth of seedlings. Crop physiologists try to mitigate these contradictions by using chemical regulation techniques. Over the past decade NAA, MH, CEPA and Kenbyo