Study on differences of net photosynthetic rate of leaf in different corn types.

Differences of net photosynthetic rate of leaf at different positions in maize of loosely type(Nongda364) and compact type(Zhengdan958) were studied in field experiment.The results were as follows:① In comparison of net photosynthetic rate of corn,it could reduce error by choosing the average net photosynthetic rate of different leaf positions.② The maximum net photosynthetic rate of different plant types of corn showed ear leafthe 10th leafthe 6th leafthe 22th leafthe 3rd leaf,providing better condition of light will be helpful to increase the yeild of maize.③ There was not significant difference in the maximum net photosynthetic rate at the same leaf among different corn types,the difference of net photosynthetic rate of the same leaf position among different corn types,found chiefly in later development period of leaves,and there was significant difference in leaves above the 10th leaf position.④ Net photosynthetic rate of leaves above the 10th leaf position in Zhengdan958 were lower than Nongda364 and declined by a large margin in later development period,improving the ability of solar energy utilization would be beneficial development of Zhengdan958.