Maize Stalk Lodging: Quantitative and Qualitative Analysis of the Structural Failure Process

Stalk lodging is the event of failure just below the ear or node. The most common failure mode is Brazier (localized) buckling, which occurs consistently near the node. Although maize stalk lodging has been a subject of study for many years, relatively little is known about the process and progression of stalk failure. Of particular interest is the issue of failure initiation. An understanding of failure initiation could be beneficial talks that are less susceptible to failure. The purpose of this study was to characterize the tissue-level failure patterns of maize stalks. Various techniques were used to examine the failure region, including imaging (scanning electron microscope, X-ray computed tomography, photographs of the failure progression), experimentation (surface strain measurements, quantification of cross-sectional ovalization). We found that ovalization occurs prior to stalk failure and that ovalization is generally correlated with the onset of buckling. However, ovalization was predictive of failure. Tissue-level analysis revealed that buckling occurs at many different scales, including organ (specifically the stalk) level, tissue level, cellular level, and at the level of the cell wall. Based on our observations, we propose a new conceptual model for stalk failure that makes sense of the mixed data on this topic. This model states that the probability of tissue and buckling failure rise together in a highly correlated fashion and that when one failure mode occurs, it immediately initiates the corresponding mode. This information provides new insights into maize stalk failure and suggests that efforts to improve stalk strength will need to address both tissue strength and buckling resistance simultaneously.