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Digital age brings diagnostics to field

A COUNTY Extension agent in Robertson County, Tenn., needed an answer quickly. Were the leaf spots in a farmer's wheat crop from a fungus or herbicide drift?

University of Tennessee Extension plant pathologist Melvin Newman took one look at the leaf and immediately knew it was herbicide drift. The farmer would not need to treat the field with a fungicide.

What's interesting about this diagnosis is that Newman never had to leave his office in Jackson, Tenn., over 120 miles away, to determine what caused the problem.

The diagnosis was made with the help of digital images sent over the Internet and took about 30 minutes from the time the call was made from the county agent's office.

This project is called Distance Digital Diagnostics. Newman estimates between two-thirds and three-fourths of Tennessee counties already have some of the components needed to participate in the fast-growing project. Some offices may have just a digital camera, others a digital camera and a microscope. Between 10 and 15 county offices have an entire mini-diagnostic center - computer with Internet access, digital camera and one to two microscopes. A complete diagnostic center costs around $10,000.

The project seems especially suited for Tennessee, over 500 miles in length from Bristol to Memphis, with 95 counties in between, but only one plant pathologist in field crops, Newman. The scientist can't pack up and hit the road to personally check out every request.

Newman stresses that each of the state's 95 county Extension offices will always be the first line of diagnostic assistance for farmers and ranchers. "Our county agent is still the No. 1 one person in the county for diagnosing problems," he said.

But sometimes a farmer, rancher or gardener brings in a specimen that stumps even the most knowledgeable county agent, and a specialist like Newman is needed to take a closer look.

That's when distance diagnostics can save time for everyone, according to Newman. The county agent shoots several digital images of the specimen or goes to the field to get additional shots. Back at the office, he accesses the state's diagnostic website, fills out a form and sends it and up to five digital images to the website.

The website is monitored by diagnosticians at the state's primary diagnostic laboratory at Ellington Center, in Nashville, run by Tom Stebbins. During the peak-growing season, 20-30 electronic requests may come in per day with questions on anything from ticks to tobacco.

On occasions when the lab can't make a diagnosis, the request will be forwarded to a specialist like Newman. "I may take a look at it and it may be Septoria leaf spot on soybeans," Newman said. "Likewise, there may be something on tobacco that some specialist in Knoxville is more knowledgeable about. We can pop it over there, just like that."

Newman notes that some county agents have become quite adept at shooting microscopic digital images of actual spores and fungi attacking a plant. Distance digital diagnostics does require initial training of county agents on how to collect specimens and mount slides.

The new technology definitely beats sending specimens by mail, another option when county agents are stumped by a problem. The specimens would usually arrive three to four days later, often in a state of advanced deterioration. Many times, Newman couldn't make a diagnosis under those circumstances and he would have to schedule a road trip to view the site in person.

Distance diagnostics doesn't mean Newman will eliminate travel, however. "Eighty percent of the time, we can solve the problem with distance diagnostics. There'll be some situations where I'll have to go out to the field and take a look. That's one thing that we have to be careful of, to hand out a diagnosis without being sure. We won't do that. We'll pack up and go to the site."

Newman noted that county agents and even farmers can bypass the website and e-mail an image directly to Newman. The farmer doesn't necessarily have to have a digital camera, either. Many film processors today can digitize photographic images onto a computer disk.

On the other hand, the diagnostic website is a closed, secure system, noted Newman. "If you have something you want me to diagnose, only the person making the diagnosis will see it. If we want guests to view it, they can. But it's totally confidential."

The digital world has other advantages, according to Newman. Today, a large part of his office space at the West Tennessee Experiment Station in Jackson is devoted to filing cabinets full of color slides of crop diseases. Over time, the slides will be replaced by digital images stored in a computer. He can use them for slide shows using his laptop computer, educational publications and for Web libraries and never have to worry about misplacing an original slide.

Newman notes the Nashville lab is also building a digital library of images, which would be available to anyone who has access to the website, including county agents.

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