Mechanical properties of maize fibre bundles and their contribution to lodging resistance

Tensile properties of fibre bundles were estimated according to their location in the stem. The average tensile modulus and tensile strength in the core group of the fibre bundles (4.44 ± 0.28 GPa and 32.35 ± 2.07 MPa, respectively) were significant lower than that in the skin group (10.80 ± 0.62 GPa and 92.65 ± 6.23 MPa, respectively). The large variation of tensile properties can be attributed to the large difference in the ratio of the areas of the vascular bundle sheath and the fibre cell wall thickness. Gradient distribution of bundle stiffness is found along the radial and axial direction of stem. Such gradient distribution increases the stiffness of basal stem; thus it is a key factor of lodging resistance for maize plants.