种植密度对京冬8号和济麦22单株生产力和产量的影响

为确定冀东地区小麦种植密度对单株生产力和产量的影响，选用京冬8号和济麦22为供试材料，设计4个种植密度水平（基本苗数量分别为300万，450万，600万，750万株／hm2），在大田条件下研究了种植密度对小麦单株生产力和产量的影响。结果表明：在本试验条件下，随密度的增加小麦单株穗数、单株穗粒数、单株干物质积累和经济系数均呈降低趋势，导致小麦单株产量随密度增大而呈下降趋势。京冬8号群体产量随着密度的增加而逐渐增加，在基本苗数量750万株／hm2下产量最高。济麦22随着密度的增加群体产量呈单峰曲线变化，在基本苗数量600万株／hm2下产量最高。综上可见，随种植密度的增大，小麦单株生产力呈下降趋势，而群体产量呈先增大后下降的趋势。

Effects of Seedling Rate on Plant Productivity and Grain Yield of Jingdong 8 and Jimai 22

In order to provide a theoretical basis of wheat high-yield in eastern area of Heibei province, the study selected two wheat cultivars ： Jingdong 8 and Jimai 22, and set four seedling rates （3.0, 4.5, 6.0 and 7.5 million seedlings per hm2 ） to investigate the effects of sowing density on plant yield potential. The results showed that spike number and dry matter accumulation per plant, grain number, and economic coefficient de- clined with the increase of seedling rate. In the conditions of this study, grain yield per plant decreased, while yield per m2 exist differences between the two cultivars. To Jimai 22, yield per m2 showed an unimodal curve with the seedling rate increase and reached the highest yield at 6.0 million seedlings per hm~. However, yield per ms of Jingdong 8 enhanced with the increase of seedling rate. In conclusion, with the increasing of seed- ling rate, single wheat plant productivity decreased, while grain yield of wheat stand increased firstly and then decreased.