- The Washington Times - Friday, February 4, 2000

Kudzu, an ivylike plant whose swift and aggressive growth has spun tall tales of peril in the Deep South (some Southerners insist it can reach into passing cars to snatch small children), may have met its match.

Federal plant scientists say they have identified a common fungus that kills the vine within hours.

Unfortunately, the fungus, known as Myrothecium verrucaria, also kills cotton, soybeans and a fairly wide variety of other plants that make up the South's most valuable cash crops.

But plant pathologist C. Douglas Boyette says it can be applied to kudzu in lethal doses without endangering other plants.

However, like Southerners who have learned the hard way to respect kudzu's prowess, he is skeptical of actually defeating kudzu. "I don't know about winning the war with kudzu, but we're going to do battle with it," Mr. Boyette says in a telephone interview from his U.S. Agricultural Research Service laboratory in Stoneville, Miss.

In greenhouse and field studies, the scientists found that the fungus killed 100 percent of kudzu plants. The fungus destroys leaves and stems and also appears to invade the potatolike roots, which serve as reservoirs of starch from which new kudzu vines grow even after stems and leaves are mown or killed with herbicides.

Kudzu, native to Japan, was introduced into the United States in the late 19th century. It was originally promoted for erosion control and as an inexpensive forage for livestock. It has crept over an estimated 7 million acres, from Florida to Texas, and has become as common as the Confederate battle flag bumper sticker in Alabama, Arkansas, Georgia and Mississippi. Large trees, junkyards, even small houses have been swallowed up by the dark-green vines, leaving grotesque and ghostly sculptures along Southern roadsides. In recent years, it has begun to creep up the Atlantic coast, and is occasionally seen as far north as New York.

The fungus M. verrucaria grows practically everywhere, Mr. Boyette says even on kudzu vines. However, in its natural state it exists in small colonies. The trick to killing kudzu with it is to produce trillions of microscopic fungus spores and mix them in a liquid solution that can be sprayed on the vines. The solution contains more than 20 million spores in a volume of spray equal to that of a sugar cube.

"We get upwards of 100 percent control," Mr. Boyette says. "Within 24 to 48 hours, the plant is dead."

To determine whether the fungus spray spreads to non-target species, Mr. Boyette sprayed kudzu with the solution in tests adjacent to soybean fields and found no damage to the beans. When washed off the kudzu leaves, as might happen if a heavy rain follows an application, the solution is diluted to the point of being harmless, he says.

Even so, environmental and toxicological studies now under way must be finished before the fungus mix is generally available to kudzu foes, he says.

That may take as long as two years, Mr. Boyette says. Meanwhile, a Department of Agriculture spokesman says the government likely will seek a patent on use of the fungus against kudzu.

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