A grape-grower in Wapato consistently produced stunted crops. Sometimes, there were no crops at all.

Washington State University researchers dug into the soil to find out what was harming Andrew Schultz' grapevines.

Researchers ran several tests, finally discovering the soil was contaminated with Tobacco Ringspot Virus.

“That was a huge surprise,” Naidu Rayapati, an associate professor at WSU said in a statement. “It was a revelation that we have a new problem here.”

The virus was originally discovered 90 years ago in Virginia. It's a problem that affects several crops, like grapes, apples, cherries and common weeds.

It's transmitted by tiny soil worms called nematodes.

After 10 years, the land becomes useless, Rayapati said. Usually, viruses can be gotten rid of by removing the crops. But not TRSV.

The small worms are difficult to kill without chemicals. But even then, they can spring back within a season or two, the researchers said.

“TRSV has a broad host range, and can jump easily from one plant species to another. That’s why we’re trying to alert growers,” Rayapati said. “If you’re planning to switch crops, it’s a good idea to get your soil tested to see if you’re at risk of these nematode vectors.”

The wine industry accounts for $8.4 billion in the state. Across Washington, there are more than 60,000 acres of grapes.

Soil and plant testing is available through Rayapati's group or commercially, WSU said. Learn more about WSU's work in wine.