Researchers analyzed the growth of summer maize in Zhengzhou City from 1994 to 2006. They found that the leaves of the plant grow quickly before the jointing stage, making up most of the plant's total dry matter. The leaf sheath also grows rapidly during the jointing stage, while the stem reaches its peak dry matter during the heading stage. After heading, the ear of the plant dramatically increases in dry matter, becoming the largest portion of the plant's total dry matter.