The studies on synchrony of differentiation, silking and kernel bearing between apical and sub-apical ear in forage maize were conducted in the cold upland of north-west Hebei province, where the maize prolificacy is enhanced.

• 在有利于玉米双穗发生的冀西北高寒地区，通过对典型多育组合农大103和典型单育品种克单6双穗分化进程的观察发现，二者第1、2果穗分化的同步性明显不同。 同时发现在分化、抽丝和成穗的发育进程中，它们各自双穗发育的同步性是前后一致的。