Wisconsin researchers are taking a multi-prong approach to help growers manage late blight, the fungal disease that caused the Irish potato famine.

Two strains of late blight attack potatoes in Wisconsin, according to a news release. And so far, they haven't combined to reproduce a new super strain.

The latest strain, called US-23, can destroy an untreated field within a week.

It also can hit tomato fields, since potatoes and tomatoes belong to the same plant family.

University of Wisconsin-Madison researchers are seeking the weak link in Phytophthora infestans, the organism that causes late blight.

They also are advising growers about best management practices, characterizing new late blight strains and looking at the genetics of the disease.

Amanda Gevens, an assistant professor, coordinates Blitecast, a prediction model that warns farmers when conditions are ripe for blight.

Jiming Jiang, a professor of horticulture, helped identify a resistance gene called "RB" in 2003.

Because it comes from a distant potato relative, it can't be incorporated through traditional breeding methods.

It would have to come through genetic engineering.

But one resistance gene won't be the silver bullet.

The disease already has overcome other resistance genes, and there's no doubt it would probably overcome this one, too.

Strains in Central America and Mexico already have overcome RB.

Dennis Halterman, a U.S. Department of Agriculture geneticist in Madison, is looking at a molecule called IPI-O in Phytophthora that can turn off RB.

"We believe Phytophthora needs IPI-O to cause disease," he said in the release"If we can target that molecule, we think that would lead to broad spectrum resistance."