David G Schmale

David G Schmale
Virginia Polytechnic Institute and State University | VT · Department of Plant Pathology, Physiology, and Weed Science

Ph.D.

About

155
Publications
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Introduction
David Schmale is a professor in the College of Agriculture and Life Sciences at Virginia Tech. He received his B.S. from the University of California, Davis, and his Ph.D. from Cornell University. His laboratory uses unmanned systems to sample microorganisms in the lower atmosphere and in water. Many microbes relevant to crops, domestic animals, and humans are transported over long distances in the atmosphere. The ability to track the movement of these microbes in the atmosphere and in water is essential for establishing effective quarantine measures and forecasting disease spread. Popular Science magazine named David one of 2013's Brilliant Ten. A feature highlighting his work was published in Scientific American in 2017.

Publications

Publications (155)
Article
Full-text available
Freshwater harmful algal blooms (HABs), caused mostly by toxic cyanobacteria, produce a range of cyanotoxins that threaten the health of humans and domestic animals. Climate conditions and anthropogenic influences such as agricultural run-off can alter the onset and intensity of HABs. Little is known about the distribution and spread of freshwater...
Article
Wheat and other staple crops are devastated by fungal diseases. Many fungal plant pathogens are spread via active or passive discharge of microscopic spores. Here, we described the unique transport of spores of the fungal pathogen Epicoccum tritici , causal agent of black sooty mould, on wheat awns. The unique multi-scale architecture of wheat awns...
Article
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Little is known about the transport and fate of aerosolized particles associated with harmful algal blooms (HABs). An Airborne DROne Particle-monitoring System (AirDROPS) was developed and used to monitor, collect,...
Poster
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New on-demand wind profiling methods are needed to track, predict, and mitigate the atmospheric transport of aerosolized agents threatening communities that live near contaminated bodies of water (e.g., lakes suffering from harmful algal blooms, oceans plagued with red tides, and rivers laced with poisonous industrial runoff). Reliable measurements...
Article
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New tools and technology are needed to track hazardous agents such as oil and red tides in our oceans. Rhodamine dye (a surrogate hazardous agent) was released into the Atlantic ocean in August 2018, and experiments were conducted to track the movement of the dye near the water surface within three hours following the release. A DrOne Water Samplin...
Article
New information is needed regarding the types and concentrations of mycotoxins in swine feed. We hypothesized that (1) the mycotoxins deoxynivalenol (DON), 3-acetyldeoxynivalenol (3-AcDON), 15-acetyldeoxynivalenol (15-AcDON), nivalenol (NIV), and zearalenone (ZEN) vary among swine ingredient and feed types, and (2) the inclusion of specific ingredi...
Article
Full-text available
Fusarium graminearum is ranked among the five most destructive fungal pathogens that affect agroecosystems. It causes floral diseases in small grain cereals including wheat, barley and oats, as well as maize and rice. We conducted a systematic review of peer-reviewed studies reporting species within the Fusarium graminearum species complex (FGSC) a...
Article
Significance Some fungal diseases spread within and among crops via the aerial dispersal of microscopic spores. Existing studies have characterized the liberation and dispersal of spores via wind and/or rain splash. Here, we show that dew droplets spontaneously jumping from superhydrophobic wheat leaves can disperse adhered spores, even in the comp...
Article
Full-text available
Heterogeneous ice nucleation plays an important role in many environmental processes such as ice cloud formation, freezing of water bodies or biological freeze protection in the cryosphere. New information is needed about the seasonal availability, nature, and activity of ice nucleation particles (INPs) in alpine environments. These INPs trigger th...
Article
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The contamination of brewers’ spent grains (BSG) with mycotoxins may pose a significant threat to the health of domestic animals that consume BSG as feed. New information is needed regarding the presence of mycotoxins throughout commercial beer and BSG production. Samples (n = 106) were collected during production of a single batch of commercial be...
Preprint
Full-text available
Fusarium graminearum is ranked among the five most destructive fungal pathogens that affect agroecosystems. It causes floral diseases in small grain cereals including wheat, barley and oats, as well as summer crops such as maize and rice. We conducted a systematic review of peer-reviewed studies reporting species within the Fusarium graminearum spe...
Article
Fusarium meridionale and F. graminearum both cause Gibberella ear (GER) and stalk rot (GSR) of maize in Brazil, but the former is much more common. Recent work with two isolates of each from maize suggested this dominance could be due to greater aggressiveness and competitiveness of F. meridionale on maize. We evaluated pathogenicity and toxigenici...
Article
Full-text available
In alpine environments, many plants, bacteria, and fungi contain ice nuclei (IN) that control freezing events, providing survival benefits. Once airborne, IN could trigger ice nucleation in cloud droplets, influencing the radiation budget and the hydrological cycle. To estimate the atmospheric relevance of alpine IN, investigations near emission so...
Article
Full-text available
Plant disease outbreaks are increasing and threaten food security for the vulnerable in many areas of the world. Now a global human pandemic is threatening the health of millions on our planet. A stable, nutritious food supply will be needed to lift people out of poverty and improve health outcomes. Plant diseases, both endemic and recently emergin...
Article
Full-text available
Ocean hazardous spills and search and rescue incidents are becoming more prevalent as maritime activities increase across all sectors of society. However, emergency response time remains a factor due to the lack of information available to accurately forecast the location of small objects. Existing drifting characterization techniques are limited t...
Article
‘SB255’ (Reg. no. CV‐373, PI 693987) is a six‐rowed hulled barley (Hordeum vulgare L.) cultivar with winter growth habit. The cultivar was released by the Virginia Agricultural Experiment Station in May 2019. SB255 is widely adapted, high yielding, high grain volume weight, and medium tall. It has good winterhardiness and good straw strength. The s...
Article
Increases in the salt concentration of freshwater result in detrimental impacts on water quality and ecosystem biodiversity. Biodiversity effects include freshwater microbiota, as increasing salinity can induce shifts in the structure of native freshwater bacterial communities, which could disturb their role in mediating basal ecosystem services. M...
Article
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Maple trees (genus Acer) accomplish the task of distributing objects to a wide area by producing seeds, known as samaras, which are carried by the wind as they autorotate and slowly descend to the ground. With the goal of supporting engineering applications, such as gathering environmental data over a broad area, we developed 3D-printed artificial...
Preprint
Gibberella ear (GER) and stalk rot (GSR) of maize in Brazil are caused mainly by Fusarium meridionale, while F. graminearum is the more common cause of Fusarium Head Blight (FHB) on wheat. Our previous study of two maize isolates of each species suggested that this pattern of dominance may be due to greater aggressiveness and competitiveness of F....
Article
In Brazil, Gibberella ear rot (GER) of maize is caused mainly by Fusarium meridionale (Fmer), while F. graminearum (Fgra) is a minor contributor. To test the hypothesis that Fmer is more aggressive than Fgra on maize, six experiments were conducted in the south (summer), and one in the central-south (winter), totaling seven conditions (year ✕ locat...
Preprint
Full-text available
Ocean hazardous spills and search and rescue incidents are more prevalent as maritime activities increase across all sectors of society. However, emergency response time remains a factor due to a lack of information to accurately forecast the location of small objects. Existing drifting characterization techniques are limited to objects whose drift...
Article
Full-text available
Unmanned aircraft systems (UASs) offer innovative capabilities for providing new perspectives on the atmosphere, and therefore atmospheric scientists are rapidly expanding their use, particularly for studying the planetary boundary layer. In support of this expansion, from 14 to 20 July 2018 the International Society for Atmospheric Research using...
Article
Full-text available
Scientific communication is facilitated by a data-driven, scientifically sound taxonomy that considers the end-user's needs and established successful practice. Previously (Geiser et al. 2013; Phytopathology 103:400-408. 2013), the Fusarium community voiced near unanimous support for a concept of Fusarium that represented a clade comprising all agr...
Article
Full-text available
Silver birch (Betula pendula) is known to contain ice-nucleating macromolecules (INMs) to survive in harsh environments. However, little is known about the release and transport of INMs from birch trees into the atmosphere. In this study, we conducted in situ and in vivo investigations on INMs from nine birches growing in an alpine valley (Ötztal,...
Preprint
In Brazil, Gibberella ear rot (GER) of maize is caused mainly by Fusarium meridionale (Fmer), while F. graminearum (Fgra) is a minor contributor. To test the hypothesis that Fmer is more aggressive than Fgra on maize, three experiments were conducted in the south (subtropical summer), and one in the central-south (tropical winter) of Brazil, totali...
Preprint
Full-text available
Maple trees (genus Acer) accomplish the task of distributing objects to a wide area by producing seeds which are carried by the wind as they slowly descend to the ground, known as samaras. With the goal of supporting engineering applications, such as gathering environmental data over a broad area, we developed 3D-printed artificial samaras. Here, w...
Article
Zearalenone (ZEN) is a potent estrogenic toxin in swine, contributing to economic losses in herds via reproductive consequences such as pelvic organ prolapse (POP). To better understand the relationship between ZEN-consumption and reproductive symptoms, an animal feeding study with pubertal gilts was designed. The gilts were exposed to three differ...
Article
Full-text available
The mycotoxin zearalenone (ZEN) is a common contaminant of swine feed which has been related to a wide range of reproductive anomalies in swine, such as pelvic organ prolapse, anestrous, and pseudopregnancy. New information is needed to understand how ZEN and related metabolites accumulate in swine reproductive tissues. We conducted a feeding study...
Article
‘Hilliard’ (Reg. no. CV‐1163, PI 676271), a soft red winter (SRW) wheat (Triticum aestivum L.) developed and tested as VA11W‐108 by the Virginia Agricultural Experiment Station, was released in March 2015. Hilliard was derived from the cross ‘25R47’/‘Jamestown’. Hilliard is widely adapted, from Texas to Ontario, Canada, and provides producers with...
Article
Use of genetic resistance is one of the most important strategies to manage the devastating disease Fusarium Head Blight (FHB) in wheat. Numerous QTL having varying effects on reducing FHB and mycotoxin deoxynivalenol (DON) accumulation have been reported from Asian, European or distant sources such as wild relatives of wheat. However, coming from...
Preprint
Full-text available
Silver birch (Betula pendula) are known to contain ice-nucleating macromolecules (INMs) to survive in harsh environments. However, little is known about the release and transport of INMs from birch trees into the atmosphere. In this study, we conducted in-situ and in-vivo investigations on INM from nine birches growing in an alpine valley (Ötztal,...
Article
Full-text available
Wheat is threatened by diseases such as leaf rust. One significant mechanism of disease spread is the liberation and dispersal of rust spores due to rainsplash. However, it is unclear to what extent the spore-laden splashed droplets can transmit the disease to neighbouring leaves. Here, we show that splashed droplets either bounce or stick, dependi...
Preprint
Full-text available
Unmanned aircraft systems (UAS) offer innovative capabilities for providing new perspectives on the atmosphere, and therefore atmospheric scientists are rapidly expanding their use, particularly for studying the planetary boundary layer. In support of this expansion, from 14–20 July 2018 the International Society for Atmospheric Research using Remo...
Article
Significant losses in wheat result from Fusarium head blight (FHB) and its associated mycotoxin deoxynivalenol (DON). The predominant FHB pathogen in North America is Fusarium graminearum. F. boothii was recently confirmed for the first time in the United States as a causal agent of FHB in Nebraska wheat fields. This greenhouse study compared the a...
Article
Full-text available
New strategies are needed to mitigate the mycotoxin deoxynivalenol (DON) in feed and food products. Microbial DNA fragments were generated from a library of DON-tolerant microorganisms. These fragments were screened in DON-sensitive yeast strains for their ability to modify or transport DON. Fragments were cloned into a PCR8/TOPO vector, and recomb...
Article
Full-text available
The processes removing aerosols from the atmosphere during rainfall are generically referred to as scavenging. Scavenging influences aerosol distributions in the atmosphere, with consequent effects on cloud properties, radiative forcing, and human health. In this study, we investigated the below-cloud scavenging process, specifically focusing on th...
Article
Fusarium head blight (FHB) and the associated mycotoxin deoxynivalenol (DON) negatively impact the wheat industry worldwide. In North America, FHB is mainly caused by Fusarium graminearum sensu stricto. The purpose of this study was to evaluate, under storage conditions, the expression of the DON biosynthetic gene trichodiene synthase (Tri5) of F....
Article
Full-text available
Some biological particles and macromolecules are particularly efficient ice nuclei (IN), triggering ice formation at temperatures close to 0 ∘C. The impact of biological particles on cloud glaciation and the formation of precipitation is still poorly understood and constitutes a large gap in the scientific understanding of the interactions and coev...
Article
Fusarium head blight, caused mainly by Fusarium graminearum Schwabe, results in major losses in wheat. In two separate field experiments, spikes of winter wheat cultivars ‘Overland’ (moderately resistant) and ‘Overley’ (susceptible) were sprayed at anthesis with the triazole fungicide Prosaro (prothioconazole + tebuconazole) or the strobilurin fung...
Article
Because unmanned aircraft systems (UAS) offer new perspectives on the atmosphere, their use in atmospheric science is expanding rapidly. In support of this growth, the International Society for Atmospheric Research Using Remotely-Piloted Aircraft (ISARRA) has been developed and has convened annual meetings and “flight weeks.” The 2018 flight week,...
Article
Microbes in the atmosphere have broad ecological impacts, including the potential to trigger precipitation through species and strains that act as ice nucleation particles. To characterize spatiotemporal trends of microbial assemblages in precipitation we sequenced 16S (bacterial) and 18S (fungal) rRNA gene amplicon libraries collected from 72 prec...
Article
Full-text available
Sorghum has gained popularity with consumers as a grain source with its gluten-free and high protein dietary characteristics. Acreage has increased recently, in part due to the demand for an alternative feed source for poultry and swine. New information is needed about the level of mycotoxin contamination in sorghum accessions, and accurate and aff...
Article
Full-text available
Some biological particles and macromolecules are particularly efficient ice nuclei (IN), triggering ice formation at temperatures close to 0 °C. The impact of biological particles on cloud glaciation and the formation of precipitation is still poorly understood and constitutes a large gap in the scientific understanding of the interactions and co-e...
Article
Full-text available
As Arctic temperatures rise at twice the global rate, sea ice is diminishing more quickly than models can predict. Processes that dictate Arctic cloud formation and impacts on the atmospheric energy budget are poorly understood, yet crucial for evaluating the rapidly changing Arctic. In parallel, warmer temperatures afford conditions favorable for...
Article
We show that condensation growing on wheat leaves infected with the leaf rust fungus, Puccinia triticina, is capable of spontaneously launching urediniospores off the plant. This surprising liberation mechanism is enabled by the superhydrophobicity of wheat leaves, which promotes a jumping-droplet mode of condensation powered by the surface energy...
Article
Full-text available
Harmful Algal Blooms (HABs) have been observed in all 50 states in the U.S., ranging from large freshwater lakes, such as the Great Lakes, to smaller inland lakes, rivers, and reservoirs, as well as marine coastal areas and estuaries. In 2014, a HAB on Lake Erie containing microcystin (a liver toxin) contaminated the municipal water supply in Toled...
Article
Full-text available
Small unmanned aircraft systems (sUAS) are rapidly transforming atmospheric research. With the advancement of the development and application of these systems, improving knowledge of best practices for accurate measurement is critical for achieving scientific goals. We present results from an intercomparison of atmospheric measurement data from the...
Article
Full-text available
Decaying vegetation was determined to be a potentially important source of atmospheric ice nucleation particles (INPs) in the early 1970s. The bacterium Pseudomonas syringae was the first microorganism with ice nucleation activity (INA) isolated from decaying leaf litter in 1974. However, the ice nucleation characteristics of P. syringae are not co...
Article
Precipitation samples collected at or near the surface of the earth are composite samples of many different raindrops. Little is known about the abiotic and biotic components found within individual raindrops. To help fill this knowledge gap, we designed a system for collecting individual raindrops called the Liquid Nitrogen Apparatus for Isolating...
Article
Full-text available
Raindrop impact on infected plants can disperse micron-sized propagules of plant pathogens (e.g., spores of fungi). Little is known about the mechanism of how plant pathogens are liberated and transported due to raindrop impact. We used high-speed photography to observe thousands of dry-dispersed spores of the rust fungus Puccinia triticina being l...
Article
Full-text available
New tools and technology are needed to study microorganisms in freshwater environments. Little is known about spatial distribution and ice nucleation activity (INA) of microorganisms in freshwater lakes. We developed a system to collect water samples from the surface of lakes using a 3D-printed sampling device tethered to a drone (DOWSE, DrOne Wate...
Conference Paper
Full-text available
III, D. 2018. Tri5 gene expression analysis and postharvest accumulation of deoxynivalenol during storage of hard red winter wheat. Phytopathology 108:S2.22-23.
Article
Full-text available
Decaying vegetation was determined to be a potentially important source of atmospheric ice nucleation particles (INPs) in the early 1970s. The bacterium Pseudomonas syringae was the first microorganism with ice nucleation activity (INA) isolated from decaying leaf litter in 1974. However, the ice nucleation characteristics of P. syringae are not co...
Article
Full-text available
Concentrations of airborne chemical and biological agents from a hazardous release are not spread uniformly. Instead, there are regions of higher concentration, in part due to local atmospheric flow conditions which can attract agents. We equipped a ground station and two rotary-wing unmanned aircraft systems (UASs) with ultrasonic anemometers. Fli...
Article
Full-text available
The Sahara in North Africa and the Gobi and Taklamakan deserts in Asia are the primary sources of mobilized dust in the atmosphere, with regional or global airborne transport estimated at 2 to 5 billion tonnes per year. Annual Asian dust plumes take about 7 to 10 d to cross the Pacific Ocean, and often reach the northwest USA between late February...