抄録
The breaking strength and hardness of culms in barley were measured to research the physical properties of culms. Bending moment (M), bending stress (σ), and moment of inertia (I) were calculated from the breaking strength, culm diameter, and thickness of culm tissues. Consequently, the bending moment value reached the maximum in 2 weeks after the heading stage, and afterward it gradually decreased. The bending moment and hardness in Haganemugi (stiff culm variety) were apparently higher than in Sekitorisai-No. 1 (brittle culm variety), and as the reason it was considered that more sufficient growth of culms was given in the former. The hardness was unhomogeneously in each part of internodes, and it showed the lowest value at the just upper part of a node.
