Field Based Phenotyping for Stalk Lodging Resistance: Experimental Error Analysis

Abstract Background: Meeting the global demand for grain is becoming increasingly difficult due to numerous factors including climate variability, urbanization, increasingly frequent extreme weather events and drought. Stalk lodging destroys between 5%-25% of grain crops annually. Developing crop varieties with improved lodging resistance will reduce the frequency and impact of stalk lodging and consequently reduce the yield gap. Field-phenotyping equipment is critical to develop lodging resistant crop varieties, but the effectiveness of current equipment is hindered by measurement error. Relatively little research has been done to identify and rectify sources of measurement error in biomechanical phenotyping platforms. This study specifically investigated sources of error in bending stiffness and bending strength measurements which are often acquired using field-phenotyping devices. Three specific sources of error in bending stiffness and bending strength measurements were evaluated: horizontal device placement, vertical device placement and incorrect recordings of load cell height. Results: Incorrect load cell heights introduced errors as large as 130% in bending stiffness and 50% in bending strength. Results indicated that errors on the order of 15%-25% in bending stiffness and 1–10% in bending strength are common in field-based measurements. Improving operating procedures and protocols can mitigate this error. Such improvements include emphasizing attention to detail while conducting tests and improving the design of phenotyping equipment. Conclusion: Reducing measurement error in field-phenotyping equipment is crucial for advancing the development of improved, lodging-resistant crop varieties. The study found that incorrect load cell height entry and incorrect device placement both significantly contributed to measurement error in bending stiffness and bending strength measurements. These findings have important implications for reducing the yield gap in staple crops and meeting the global demand for grain.