Global Security Newswire

WASHINGTON — A group of U.S. plant disease experts hopes to combine its work with the science of a criminal investigation to protect U.S. crops against bioterrorism (see GSN, Nov. 17, 2003).

The goal of members of the American Phytopathological Society is to be able to determine the origins of dangerous plant microbes, allowing investigators to track them in case of an attack and possibly even deter an incident.

“It involves new levels of application of our science,” said Jacqueline Fletcher, a plant pathology professor at Oklahoma State University. “We do have a lot that we can bring to bear now, but we need to do more work,” she added.

There are no present indications that terrorists are planning attacks on U.S. crops, Fletcher said. However, the U.S. Agriculture Department believes “it’s not a matter of if, it’s a matter of when” such an attack will occur, said Gerald Holmes, an assistant plant pathology professor at North Carolina State University. 

Microbes that attack plants are accessible, relatively safe for people to handle and easy to disperse, Fletcher said. The ethical quandary is reduced, as those who might balk at harming humans are unlikely to feel the same sympathy for plant life.

Terrorists, however, might not look first to crops in their efforts to attack the United States, said Gail Wisler, chairwoman of the University of Florida’s Plant Pathology Department. “A bunch of burning cattle or a person with smallpox is certainly more attention-getting than diseased plants,” Wisler said.

Nevertheless, the potential for such an effort should not be discounted, Wisler said, and the economic impacts could be huge.

The Agriculture Department lists nine high-priority pathogens that could be used to attack crops of everything from wheat to corn to citrus fruit, Fletcher said. Naturally occurring pathogens already cause 65 percent of crop losses for U.S. producers, costing them $137 billion each year, she said.

An attack could range from using a crop-dusting plane or other aerial means, to spray an area with a pathogen, to simply introducing a diseased plant into a field, Holmes said.

A dispersed plant pathogen could damage and kills crops at one farm or, over time, an area of hundreds of thousands of acres. Smaller crops mean producers and sellers lose money while consumers pay more, and it would take only one confirmed report of a plant disease for that crop to be quarantined against international distribution, Wisler said. Along with the losses would come the cost of managing the disease.

Any country that produces agriculture — which is to say, almost all of them — would have people trained to work with plant diseases, Fletcher said. Most are seeking to defeat disease, but “the potential is certainly there” for them to work in the opposite direction, she said.

The United States and the Soviet Union both stockpiled crop killers like rice blast and wheat rust during the Cold War. U.S. scientists went the extra mile by developing a “feather bomb,” a missile containing bunched turkey feathers carrying wheat rust spores that could detonate overhead and infect crops as the feathers touched down.

Rihab Taha, the former Iraqi biological weapons scientist known as “Dr. Germ,” studied plant diseases in the United Kingdom and received her doctorate in tobacco pathogens.

“I’ll guarantee you if you say, ‘Terrorists will never do that,’ they’ll do it tomorrow,” said William Cobb, a private plant pathology consultant in Kennewick, Wash., who has served on an APS committee on microbial forensics. “I always look at it as what’s the worst-case scenario and am I prepared for it? I think this falls into that area,” he said.

Sciences Against TerrorismThe normal work of a plant pathologist in the United States is to study the 50,000 diseases that afflict U.S. plants in hopes of reducing their effects. 

Forensic science is the application of science to the law, according to the British Forensic Science Society. For police, that means the collection of physical traces — from blood to hair fibers — to support a criminal investigation and eventual trial.

For Fletcher, combining the two means being able to determine features of a pathogen that could lead investigators to its creator and to prosecution.

Plant pathologists are already doing some work in this area. Cobb has conducted crop-loss investigations for 16 years; roughly 10 percent of his investigations involve litigation. The work he does in preparing for a court case, including extensive laboratory work and specimen sampling, would carry over into this new field.

Fletcher wants to take her science further, to the point where investigators would be able to better discriminate between different strains of the same pathogen and even map the DNA of a large number of those strains. That would require in-depth investigations of high-threat strains, but could ultimately allow scientists to determine if a pathogen is a naturally occurring strain or one intentionally modified for an attack.

There are hundreds and possibly thousands of facilities that work with plant pathogens, Cobb said. However, the numbers working with specific types is much smaller, meaning identification could fairly quickly lead to the source.

“Somebody couldn’t just get up in the morning and say, ‘I’m going to put together a powerful microbe for attacking plants,’” Cobb said.

Society members have been discussing the antiterror marriage of forensic and plant sciences for about a year, Fletcher said. They hope to organize a working group of interested scientists and raise awareness of the effort at the organization’s annual meeting beginning July 31 in Anaheim, Calif.

The next step would be to develop research policies and procedures, and to seek funding for working on the priority pathogens, Fletcher said.

Their work would add to antiterrorism efforts by the U.S. Agriculture Department and the National Plant Diagnostic Network, which this spring trained 2,500 county agents and crop consultants to become “first detectors” for potential attacks.

Microbial forensic research would take years, though useful information would be developed along the way, Fletcher said. The potential result would be a deterrent against biological attacks against crops in the United States and its allies.

Terrorists who know their pathogens can be tracked back to them could think twice about unleashing an attack on plants, Fletcher said.

“If it does happen, you have a means to trace it, to identify the perpetrator and to bring them to justice,” she said.