ENIGMA - Tim McMillan strides across his tobacco field in enigma in south Georgia, stopping to point at a sickly plant marred by brownish splotches. The leaves are curled and their network of veins -- the ductwork that carries life-sustaining nutrients -- are brown, instead of green. <br>
<br>
McMillan and other Southern flue-cured tobacco growers have been hit by the worse outbreak of tomato spotted wilt virus in years. The disease is likely to reduce growers' yields and the quality of their tobacco in a year when prices and demand are already low. Scientists don't know why the disease is worse some years and not others, and there is no cure. <br>
<br>
Tomato spotted wilt virus is spread by tiny insects known as thrips. They become infected by feeding on infected plants -- even weeds around fields. Then they pass it on to tobacco plants when they scrape the leaves to feed on the juices. <br>
<br>
Although infected plants can't be cured, some chemicals show promise in preventing infected plants from developing the full-blown disease. <br>
<br>
The virus also attacks other important Southern crops, such as cotton, peanuts and tomatoes. <br>
<br>
Spotted wilt damage in Georgia tobacco alone could easily run into the millions of dollars this summer.
