© Wisconsin Department of Agriculture, Trade and Consumer Protection
This blighted tomato plant is from a home garden in Dane County. Late blight has also been found at a Rock County vegetable farm.
Wisconsin potato growers are on alert for a highly contagious fungus that has been found on tomato plants throughout the state. Officials worry that the fungus - which caused the Irish potato famine in the mid-19th century - could make the leap to potatoes and threaten the local crop.
As of Friday, Wisconsin had at least eight confirmed cases of the late blight fungus on tomatoes in Dane, Rock, Portage and Langlade counties - including at least one commercial vegetable farm, said Amanda Gevens, a plant pathologist with the University of Wisconsin-Madison and University of Wisconsin Extension. An additional 20 to 30 suspected cases are being investigated in several counties, she said.
The fungus first appeared earlier this summer in the Northeast, possibly carried by infected seedlings at garden centers. It has spread to other parts of the country since, rapidly killing tomato plants in its path. Spores are carried by wind, rain, people, machinery and wildlife.
In other states, the fungus quickly made the leap to potatoes, which is why Gevens met with Wisconsin potato growers this week to explain the signs and to prepare growers for a potentially devastating crossover. Wisconsin - the nation's third largest potato producer behind Idaho and Washington - last year harvested 2.3 billion pounds of potatoes.
"It has now landed in the center of commercial potato production in Wisconsin, so the risk is great," Gevens said.
