Abstract
The development of culms in Sekitorisai-No. 1 brittle culm variety) and Haganemugi (stiff culm variety) was examined from the standpoint of chemical composition. Total nitrogen, protein-nitrogen, cellulose, total sugars, silica, calcium, magnesium, and potassium were quantitatively determined, the following results were obtained : the increase in total nitrogen and protein-nitrogen content was remarkable before the culm elongation stage, while the increase in cellulose was after the heading stage. On the other hand, a large amount of silica was recognized in culms of Haganemugi, and in leaf sheath of both varieties. It was considered that the amount of calcium and magnesium in culms was not closely related to the stiffness of culms. It is necessary for the stiffness of culms that amount of protein and cellulose in culms are sufficient enough for culm development and silica for silicified cell formation.
