Effects of Plant Density on Photosynthetic Character and Yield Trait in Summer Corn

Under different density conditions, different plant shape summer corn cultivars were studied aiming to choose preponderant cultivars which had high yield potential. The results showed that comparing low-density conditions corn leaf area index(LAI) was higher than high-density. The rate of photosynthesis was higher than low density conditions and the rate of photosynthesis of CF008 was the highest in all cultivars. Grain yield of CF008 was the highest and the difference was no significant between high-density and low-density, while yield of Zhengdan958 was higher under low-density conditions, which showed that CF008 could density-resistant higher than Zhengdan958. Similarly, the harvest index of CF008 was the highest and the difference was no significant in different density conditions. In a word, compact type cultivars were better than those of half compact type cultivars and CF008 was slightly better than ZhengDan 958.