Relationship between Stalk Shear Strength and Morphological Traits of Stalk Crops

Studying stalk shear strength is to provide design parameters for harvesting machinery cutter, and exploring the relationship between shear strength and morphological traits can be utilized to adjust the shear strength in selecting crop variety process. Five main stalk crops planted in northern China including wheat, corn, broomcorn, soybean, and millet, were chosen to be the samples of the experiments. About seven morphological traits (such as plant height, ear length, ear weight, moisture content and so on) were measured in the crop mature period. The maximum shear force during shearing process, through static test equipment, at the second internode of the basal stalk, was recorded. And shear strength of each crop was calculated to find the differences of shear strength among different crops. The optimal regression models of shear force and morphological traits were obtained by multiple linear regression method with Statistics Analysis System (SAS). The equation based on the regression models was constructed. It indicated that the plant height, ear weight and cross-sectional area of stalk had closer relations with shear strength. These results can be assisted to predict the shear strength.