NON-TECHNICAL SUMMARY: Wind induced crop failure (lodging) is a major agricultural problem, especially in easily digestible bioenergy crops. The problemof stalk lodging may be framed as a limitation in measurement capabilities: stalk strength must be measured accurately toenable breeders to develop stronger crop varieties. Previous measurement techniques are error-prone and unreliable. Recentresearch by Dr. Daniel Robertson suggests two approaches for accurately measuring stalk strength. These approaches arebased on structural engineering expertise and mechanical measurement principles and theory. Consequently, properdevelopment of these devices requires input from both plant scientist and biomechanical engineering experts. This projectintegrates biomechanical engineering expertise with crop science. The main outcome of the project will be development of twoportable devices for nondestructively assessing stalk strength in the field. Once validated, these devices will be applied inselective breeding studies to improve stalk strength.
OBJECTIVES: Goal: Provide plant breeders with new tools to enable development of lodging resistant corn and sorghum.Objective 1. Validate and enhance a previously designed portable electro mechanical device for measuringstalk strength and bending stiffness.• Thirty devices have been created and have been used at 18 locations by Monsanto Company, as well as in field trials of corn and sorghum at Clemson University, Texas A&M, Iowa State University, and University of Nebraska. The devices can predict stalk strength with four times the accuracy of other commonly used methods of assessing stalk strength. A patent application has been filed for the devices and industry partners are currently conducting extensive field test to evaluate licensing potential. As part of this award calibration techniques for the devices will be deveoped and the user interface will be enhaned.Research Objective 2. Create a portable device for measuring stalk area moment of inertia and rind penetration resistance.• Three preliminaryiterations of design, development and validation have been accomplished using a non-portable universal materials tester. A robust algorithm has been developed for measuring area moment of inertia and rind penetration resistance and key design features and components have been identified. It remains to combine this knowledge into a small handheld portable device that can be deployed by agronomist in the field. The future design and validation of this device will take place at the University of Idaho. Once the handheld device is developed it will be validated by comparing results to the above mentioned universal materials tester. The new portable device will also be deployed in the field and user feedback will be gathered.The utility of the device will also be tested and compared to a standard rind penetration testing apparatus.Objective 3.Incorporate multi-disciplinary research examples into undergraduate engineering courses.
APPROACH: Efforts• 1. Validate a portable device for measuring stalk strength and flexural rigidity.• 2. Design and validate a handheld device for measuring area moment of inertia and rind penetration resistance of cornstalk.• Use devices to obtain data on 50 hybrids of dent corn• Generate training manuals for devices and instruct collaborating plant breeders in device use and safety procedures.Evaluation Measures• Each of these prototypes will be evaluated for accuracy both in the field and in the laboratory.Reports will be given to industry collaborators at the completion of each phase of device development. Scientific manuscriptswill be developed and submitted for publication throughout the duration of the project. Other deliverables for the project includefabrication and deployment of final stage devices to multiple geographic locations for data collection. The final deliverable for theproject will be a written report to industry collaborators detailing utility and efficacy of designed devices. The utility and efficacyof final stage devices will be evaluated by using the devices in the field and comparing their results to those of rind penetrationtests. Device ergonomics, time to phenotype, user fatigue, and accuracy of stalk strength predictions will be assessed.