USDA NIFA Postdoctoral Fellow University of Delaware Morgantown, West Virginia
Body of Abstract: Plant mechanical failure, known as lodging, has detrimental impacts on the quality and quantity of maize yields. Failure can occur at stalks (stalk lodging or greensnap) or at roots (root lodging). The ability to assess plants for root lodging susceptibility has been limited due to a lack of reliable metrics associated with root failure. Prior work has shown that the root system is best modeled as a spring. We hypothesized that the stiffness of this spring (i.e., root torsional stiffness) is related to root lodging susceptibility. Here we report a tool, SMURF (Sorghum & Maize Under Rotational Force), which non-destructively quantifies root torsional stiffness in the field. To test our hypothesis, the root torsional stiffnesses of maize hybrids with variable susceptibilities to root lodging, were measured over multiple years and across multiple planting densities. The results show that 1) hybrids with a higher root torsional stiffness had greater root lodging susceptibility and 2) root torsional stiffness was reduced with increasing planting density, which is known to increase root lodging susceptibility. Therefore, while root torsional stiffness is related to root lodging susceptibility, this metric should be interpreted in the context of the planting density and resulting plant architecture. Collectively, these results demonstrate the utility of the SMURF device for providing a quantitative, non-destructive assessment of root anchorage.