Field-Based High-Throughput Phenotyping Using Radiometric Observations.

Field-based high-throughput phenotyping using radiometric observations  Andrew N. French, Pedro Andrade-Sanchez, Michael Gore, Mike Salvucci, Kelly Thorp, and Jeffrey W. White

A major challenge for agriculture in the next 50 years is the need to double food production to meet demands placed by a projected global population of 9 billion people. The challenge is acute because of increasing demands for limited natural resources, unprecedented population growth, and especially because of greater prevalence of drought and heat stress. Meeting this challenge will require new approaches to rapidly develop high-yielding, stress-tolerant varieties. Successes with field-based radiometry to characterize plant physiological responses to differential water and nitrogen treatments suggest that these same techniques can be adapted to high-throughput phenotyping (HTP). Research now underway in Maricopa, Arizona seeks effective ways to use multispectral radiometric data spanning visible, near infrared, and thermal infrared wavelengths, along with plant canopy geometric data, to detect and evaluate plant physiological responses to heat and water stress. Examples of collected data include green-red-near infrared vegetation indices, near infrared water content indices, and thermal infrared derived plant surface temperatures. Measurements of net photosynthesis, stomatal conductance, chlorophyll fluorescence and yield will be used to corroborate the remote sensing data. For the proposed HTP system, radiometric data will be collected at fine spatial scales (better than 0.5 m) and frequent temporal scales (hourly to daily) using passive and active sensor technologies. Findings from a 2010 study to genetically dissect cotton physiological responses to heat and drought stress using a tractor-mounted system will be discussed.