July 22, 2008
AMES, Iowa — Researchers at Iowa State University have been flying balloons this summer in the name of biosecurity science.
A team of plant pathologists and engineering researchers led by Forrest Nutter, plant pathology professor, are using weather balloons to carry a first-of-its-kind device developed to measure the spore clouds escaping from a diseased field of wheat. The researchers infected the field near campus with wheat rust, a fungal disease, to see if they could measure the density of spores above the crop. The spores are the microscopic infectious structures the fungus uses to spread.
The work is an offshoot of Nutter's work using satellite images to find diseased fields of soybeans in Brazil and South Africa. The research developed a method to detect soybean rust using the difference in the light reflected from the diseased plants compared with healthy soybeans and the characteristic way the disease moves through a field.
This is the final year of a U.S. Department of Agriculture grant funded through the National Research Initiative's Plant Biosecurity Program. Nutter recently won a $1.13 million grant from the Department of Homeland Security to fund research on the early detection of plant diseases in other countries using satellite technology.
Successfully gathering spores with balloons gives plant pathologists another way to target the identification of plant diseases, either natural in origin or deliberately infected.
"If a field viewed from satellites has suspicious areas, we could provide the GPS coordinates to go look at them. This makes our warning system more accurate," Nutter said.
The spore collector carried by the balloon includes six samplers that can be turned on remotely, allowing researchers to measure spore densities at different altitudes and calculate the size and density of the spore cloud. The sampler is returned to the lab to identify and count the spores.
Analyzing the spores genetically would also give investigators information on their origin, Nutter said. If the biotype of the disease is new to the region, then scientists might investigate if it was introduced deliberately. After locating a suspicious field, investigators could look for tell-tale substances that would indicate an act of bioterrorism, he said.