Evaluation of Brace Root Parameters and Its Effect on the Stiffness of Maize

Abstract

Plant mechanical failure (lodging) causes significant yield loss for crops such as maize. Understanding this failure has relied on static measurements of plant biomechanics. In this study, digital image correlation techniques are used to capture dynamic motion to understand the plant mechanical behavior of maize stalks in the presence and absence of brace roots, which are stem-borne aerial roots known to stabilize the maize stalks. The data show that brace roots function to secure the maize stalk, limiting both deflection and uplift. A finite element (FE) model is developed using ABAQUS software to validate the non-contact, video-based measured deflections captured by the dynamic motion and confirm the linear elastic behavior of the stem, following fundamental principles of engineering mechanics. Good agreement is found between the field data captured using video-based measurements and the physics-based FE model when a rotational connector element is connected at the base to quantify the 1) relative contribution and moment resistance provided by the root system, 2) displacement at any location along the stalk, and 3) flexural rigidity of the brace-stem system, where the rigidity can be associated with various phenotypes to design plant systems that are more resilient to lateral loading.