Mechanical Properties Affecting Lodging of Sorghum

10 grain sorghum cultivars were studied to find mechanical properties that would be indicative of lodging-resistant characteristics. Lodging-resistant (stiff) types were on average 7.6 cm shorter than weak types. At high moisture content, stems failed with clean breaks and little deformation; at low moisture content, deformation was greater. The leaf sheath provided additional support to that of the bare stem and exerted the greatest influence at the stem base. Responses to force were significantly different between weak and stiff genotypes, but variation among the stiff and weak genotypes complicated interpretation of these results. The modulus of elasticity of the material was not shown as being sensitive to lodging resistance. The plants acquired their maximum lodging resistance somewhere between the dough and physiological-maturity stages