Jan Shepel
Associate Editor
MADISON
Late blight, a fungal disease that can affect tomatoes, potatoes and sometimes eggplants is causing concern among vegetable and potato growers, as it is being found and confirmed by state experts in a variety of growing situations.
Rod Nilsestuen, secretary of the Department of Agriculture, Trade and Consumer Protection (DATCP), said late blight is hitting a wide variety of farms. “It has hit small farms and large farms, Community Supported Agriculture farms and organic operations, you name it,” he said.
His discussion of late blight came in his secretary’s report to members of the DATCP citizen policy board on Wednesday (Sept. 9.), in Madison.
Late blight is infamous for causing the great potato famine in Ireland, causing widespread starvation and mass migration. But so far the disease has been found in potatoes in only four Wisconsin counties: Dane, Columbia, Portage and Marathon.
Many potato growers, he said, have taken proactive measures against the disease since late blight was discovered in Wisconsin a few years ago. That includes additional fungicide applications.
Nilsestuen said the disease is “no small thing” and the crew from his Agricultural Resource Management (ARM) Division has been hard at work combating late blight and working with growers.
Amanda Gevens, a plant pathologist with the University of Wisconsin, told ag board members that late blight in tomatoes has now been confirmed in 19 counties in the state. A specialist in potatoes and other vegetables, Gevens said the worst damage caused by the outbreak this year has been on tomatoes.
“It has taken organic and small farming operations by surprise, and it has caused the worst devastation there,” she said.
Gevens said UW experts, along with the ARM Division have been working on education and prevention advice for growers.
The disease has still been found in potatoes in only four counties. Late blight had struck potato growers in the state in the late ‘90s and early years of this decade, she said, so growers had handled it before, using additional fungicide applications.
The disease this round is having minimal impact on potato growers, as most of the potato vines have died or been killed, and the weather has been dry. Having moist conditions and vines still growing in the field are conditions that could lead to spread of the disease.
The next concern for potato growers will be to get their tubers into storage and make sure they stay free of fungus, she said. Then they will move on to making sure that next year’s seed crop is free of late blight.
“So far we’ve seen no indication that any seed fields in Wisconsin have been hit with late blight,” Gevens said.
