黄淮麦区半冬性小麦冬前壮苗叶龄指标的确定

Foliar Age Determination of Sound Seedling for Semi-winter Wheat in Huang-huai Plain

选用3个有代表性的不同类型半冬性小麦品种，在河南省21个试验点（北纬32°～36°）种植，研究了冬前积温（播期）对小麦产量的影响及冬前壮苗叶龄指标的确定。结果表明：①冬前积温与产量存在二次回归关系，半冬性小麦品种的冬前积温在720℃时产量最高，表明此冬前积温下的播期是生产上的适宜播期。②半冬性小麦冬前长1片叶子所需要的积温随冬前积温增加（播期提早）而增加，河南冬前积温在450～860℃范围，长1片叶子所需要的积温在62～83℃范围内变化。③根据适宜冬前积温与出1片叶子所需积温推算，河南省冬前壮苗应处于七叶一心期，这种冬前壮苗既能充分利用冬前积温获得高产，又能保证半冬性小麦安全越冬。

Three semi-winter wheat cultivars were cultivated at twenty-one locations （from 32°N to 36°N） in Henan province to evaluate the effect of accumulated temperature before wintering on yield and to determine the foliar age of sound seedling for semi-winter wheat. The results indicated that：（1）There was quadratic regression between the accumulated temperature before wintering and yield of semi-winter wheat, and the appropriate accumulated temperature was 720℃, which provided reference for determining the suitable sowing date of wheat in Henan Province. （2）The total accumulated temperature before wintering varied from 450 to 860℃. The accumulated temperature needed per leaf was 62-83℃ ,higher for earlier sowing. （3）The foliar age of sound seedling was 7.3 based on the appropriate accumulated temperature before wintering and the accumulated temperature needed per leaf,which could gain high yield by fully using the accumulated temperature before wintering and assured safety overwintering for semiwinter wheat.