Development of a Parameterized Model of Transverse Maize (Zea maysL.) Stalk Morphology

• Main Author: Larson, Ryan A.
• Format: Others
• Published: BYU ScholarsArchive 2020
• Subjects: biomechanics; finite-element modeling; maize; parameterized models; plants; Engineering
• Online Access: https://scholarsarchive.byu.edu/etd/8981; https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=9990&context=etd

Stalk lodging, or failure of the stalk structure, presents a serious problem in the production of maize (Zea mays L.). Lodged stalks negatively impact crop yields by inhibiting further grain growth and often prevent the harvest of the grain. Addressing this problem requires the development of new maize hybrids that exhibit enhanced lodging resistance, which in turn requires an understanding of the parameters that influence lodging resistance. Current methods make use of specimen-specific geometry and material properties, but these methods have limited ability to examine geometric effects and can require excessive time. A parameterized model of the maize stalk has the potential to overcome these limitations. The purpose of this study was to develop a model of the maize stalk cross-section that could accurately predict transverse stiffness. Principal component analysis was utilized to discover underlying geometric patterns that could be used as parameters in a cross-sectional model. Using the resulting principal components, a series of approximated cross-sections was created that represented various levels of fidelity to real cross-section geometry. The real and approximated cross-sections were modeled in transverse compression with a prescribed deformation load, and the predictive accuracy of each approximated model was calculated. A sensitivity study was also performed to quantify the strength of individual parameter effects. The simplest model, an elliptical cross-section, accurately predicted transverse stiffness while minimizing the number of model parameters. This model may later be used as a basis for a three-dimensional parameterized model of the maize stem.