Hobby-size Planes May Be Future of
Early Warning System
The sight of a small yellow plane buzzing above Virginia Tech’s Kentland Farm is not a typical image of plant pathology research. But David Schmale, assistant professor of plant pathology, physiology, and weed science, has made it one as he investigates microbial life in the lower atmosphere.
“We know that microbes mediate important biochemical processes in the soil, the ocean, and a variety of extreme environments,” Schmale says. “It is not so farfetched that a similar drama unfolds in the atmosphere, which we know is teeming with microbial life.”
Schmale has given scientists an unprecedented glimpse into the life of microorganisms above the earth’s surface by using autonomous, or self-controlled, unmanned aerial vehicles (UAVs) to detect, monitor, and forecast the movement of biological agents in the atmosphere. Schmale is the first to develop and implement an autonomous UAV platform for precise aerobiological sampling above agricultural fields.
“Many plant pathogens are transported over long distances in the atmosphere, threatening agriculture in the United States from both inside and outside the borders of the country,” Schmale says. “An increased understanding of the dynamics of plant pathogens in the atmosphere is essential for establishing effective quarantine measures, preventing the spread of plant disease, and mitigating potentially damaging events targeted at our nation’s agriculture and food supply.”
Schmale hopes his UAVs will allow scientists to follow themovement of high-risk pathogens that might have a profoundimpact on agriculture, such as late blight of potato and tomato, soybean rust, and tobacco blue mold. Schmale has already used the UAVs above agricultural fields at Kentland Farm to collect samples of the fungal genus Fusarium, which contains some of the world’s most devastating plant and animal pathogens. He placed antibiotics in the collection plates of his UAVs, ensuring that only Fusarium grew from the samples. Over the course of 75 UAV-sampling flights, Schmale collected more than 500 viable colonies of Fusarium, representing at least a dozen species.
“For 11 of these species, this is the first report of their ability to be transported great distances above the surface of the earth,” says Schmale, who is an affiliate faculty member at the Virginia Center of Autonomous Systems (VaCAS), a Virginia Tech research center that facilitates collaboration on autonomous systems.
Schmale has expanded his research to explore the new and emerging field of aerogenomics – the study of entire microbial
assemblages in the atmosphere. Allan Dickerman, assistant professor at the Virginia Bioinformatics Institute (VBI), is bringing his knowledge of genomics and bioinformatics to the project. In particular, he is using VBI’s Roche GS-FLX highthroughput sequencing system to provide “very deep sampling of the biotic diversity in the atmosphere.” This will allow researchers to survey the diversity of airborne microbes.
Through this research, Schmale discovered a suite of unculturable microorganisms in the atmosphere that may be completely new to science. He hypothesized that atmospheric microbes may “have unique ways of communicating with each other in the atmosphere.” He is currently collecting more data to test this hypothesis and investigating other applications of autonomous systems in the fieldof aerobiology.