Dr David G. Schmale III, Ph.D., Fulbright AUKUS Scholar, Professor and Director, Translational Plant Sciences Center, Virginia Tech University

Date: Thursday, 24 September 10-11 am,  SARDI Auditorium

Title: Atmospheric Incursions of Plant Pathogens: From Leaf Surfaces to Continental Transport

Abstract: The atmospheric transport of plant pathogens unfolds across a continuum of scales, linking microscale release processes at leaf surfaces to long-distance movement across regions and continents. Together, these processes underpin atmospheric incursions, where pathogens cross borders unannounced and often undetected. At the smallest scale, dispersal begins with liberation from surfaces and escape through the laminar boundary layer. High-speed imaging reveals that raindrop impacts generate vortex-like flows that entrain leaf rust spores into the air, while jumping droplet condensation and cascading “billiard ball” interactions amplify spore release across leaf surfaces. At the farm scale, transport is governed by turbulent flow within the surface boundary layer, shaping dispersal across agricultural landscapes. Release–recapture studies show how fungal spores move from field-scale sources under natural conditions, while work on genetically engineered switchgrass demonstrates how pollen disperses beyond field boundaries, raising challenges for disease management and gene flow. At regional and continental scales, pathogens become entrained in the planetary boundary layer and free atmosphere, where structured airflows organize movement over hundreds to thousands of kilometers. These highways in the sky connect distant regions through coherent transport pathways, including atmospheric bridges linking Australia and New Zealand. Advances in sensing and sampling are enabling new insights into pathogen movement across scales. Integrating these observations with atmospheric transport models provides a pathway toward predictive frameworks capable of detecting, forecasting, and responding to biological threats before they arrive.

Bio: Dr. David Schmale is a Professor and Director of the Translational Plant Sciences Center at Virginia Tech. He received his B.S. from the University of California, Davis, and his Ph.D. from Cornell University. Dr. Schmale joined the former Department of Plant Pathology, Physiology, and Weed Science as an Assistant Professor in 2006, was promoted to Associate Professor in 2011, and to Full Professor in 2016. He was named one of Popular Science’s Brilliant Ten in 2013, and his work was featured in Scientific American in 2017. That article was later selected for the “Top 21 Wild Ideas in Science that Just Might Save the Planet and Us.” Dr. Schmale is the recipient of the 2026-2027 Fulbright U.S. Scholar Australia-United Kingdom-United States (AUKUS) Award. This is his second Fulbright, following a previous Fulbright in New Zealand in 2020. Working with five host institutions across Australia and the United Kingdom, he is collaborating with researchers to improve the prediction, detection, and response to atmospheric incursions of invasive crop threats using advances in aerobiology, geospatial sensing, genomics, and atmospheric modeling. Dr. Schmale has secured over 100 grants from agencies including NSF, USDA, NASA, and DARPA totaling more than $24 million, with approximately $10 million supporting his research program. His scholarly output includes over 120 peer-reviewed manuscripts, one Annual Review article, two book chapters, and three papers in The Proceedings of the National Academy of Sciences (PNAS). He has delivered invited lectures and keynote addresses in 13 countries outside the United States, including Australia, Austria, Brazil, the Czech Republic, England, France, Germany, Ireland, Italy, the Netherlands (Saba Island), New Zealand, Scotland, and Spain.

Lab Website: https://www.schmalelab.spes.vt.edu/

Email: dschmale@vt.edu

LinkedIn: https://www.linkedin.com/in/dschmale/

Instagram: @SchmaleLab

https://adelaide.zoom.us/j/88324941961?pwd=iBEvCU8wU2bKbEa3JaDzLIDGOZtEkj.1

Webinar ID: 883 2494 1961, Passcode:429141

Followed by morning tea