对不同密度条件下3个不同株型春玉米的光合特性及产量进行了研究,结果表明,单位面积有效穗数随密度增加而增加,但不同品种耐密性不同,当密度达到 The photosynthetic characteristics and yield of three different spring maize varieties under different densities were studied. The results showed that the effective spikes per unit area increased with the increase of densities, but the densities of different varieties were different. When the density reached