Food & Nutrition Security – The Biosecurity, Health, Trade Nexus
13-14 December 2021, Canberra
Professor Pablo Zarco-Tejada
Remote Sensing & Precision Agriculture, School of Agriculture and Food & Faculty of Engineering and Information Technology, The University of Melbourne
Pablo J. Zarco-Tejada is Professor and Associate Dean at the University of Melbourne. He holds degrees across disciplines obtained worldwide, such as Agricultural Engineering (Spain), Remote Sensing (UK), PhD in Earth and Space Science (Canada), held a Faculty position at the University of California, Davis, USA, becoming later the Director of the Institute for Sustainable Agriculture, National Research Council (CSIC, Spain), and Senior Scientist at the Joint Research Centre (JRC) of the European Commission. Currently, he is Professor in Precision Agriculture and Remote Sensing leading HyperSens – Hyperspectral Remote Sensing & Precision Agriculture Laboratory. He is author of more than 150 publications and has been recipient of the Highly Cited Researcher awards (2019, 2020 & 2021). He has led research projects worldwide, including capacity building activities for CGIAR in Mexico, Zimbawe, and India in the context of remote sensing and unmanned vehicles for plant phenotyping, precision irrigation and biosecurity.
Advanced monitoring techniques
ABSTRACT
Progress in the last 20 years in airborne-, space- and drone-based imaging spectroscopy has advanced tremendously. These innovations have allowed improved large-scale monitoring of crop physiological processes with unprecedented detail. Successes have been obtained in the context of biotic and abiotic stress detection, particularly with new developments in sensor miniaturization and physically- and artificial intelligence-driven modelling techniques. In 20 years, the spectral detail employed to detect stress has been exceptionally enhanced: cameras and technological imaging devices have moved from gathering data at the “hundreds of nanometers” spectral scale down to the “sub-nanometer” resolution, even reaching the Armstrong physical unit. Due to these rapid technological developments, the main focus has shifted recently, moving from a technology push in the last decade to the current algorithm-push to understand better the physiologcal interactions of crops undergoing biotic- and abiotic-induced stress. Xylella fastidiosa is currently the major transboundary plant pest, the number one threat for Australia, and the world’s most damaging pathogen in terms of socio-economic impact. As with several other pathogens, its detection under natural crop conditions, i.e. where the abiotic-induced variability due to water and nutrients co-exist with the pathogen-induced stress, requires advanced remote sensing monitoring technology and algorithms to disentangle the biotic vs. abiotic physiological interactions. These advanced methods use high-resolution hyperspectral and thermal imaging cameras onboard drones and piloted aircraft, demonstrating that uncoupling the biotic‑abiotic spectral dynamics reduces the uncertainty in the disease detection reaching accuracies over 90%. Although most currently operated drones are not carrying imaging spectrometers, efforts should be made to enable advanced remote sensing technology and algorithms with low‑cost and easy to operate platforms for widespread hyperspectral technologies worldwide. These hyperspectral methods coupled with proper algorithms will advance the early detection of devastating pathogens to reduce billions of losses worldwide.