Responses of Growth and Development,Physiology and Yield of Maize to Increasing CO₂ Concentration

Dynamic changes and responses of growth and development,physiology and yield result for pot maize were studied by controlling CO₂ concentraion with different levels of 700,600,500 and 350 ppm. The experiments show that increasing CO₂ concentration can promote growth and development of maize,shorten phenophase,enhance photosynthetic rate,decrease evaporation rate,step up biomass accumulation of roots, stems and leaves, and increase biolgical and economic yields. Effects of CO₂ concentration on maize vary in different growth phases. And the effects in the male flower phase are the most. CO₂ concentration effects on characters of plant-growth and yield is also different. Effects of CO₂ concentration on ear flower is greater than on stems and leaves, which is greater than on roots. The harvest index increases with raising CO₂ concentration. In addition,the experiments also show that high CO₂ concentration can enhance the capability of resisting stresses in high temperature and weak light.