Helicopters once buzzed across R.D Offutt's massive potato farms here, spraying fungicide about every five days.
It's how the potato industry did business, but not anymore.
Helicopters still spray and pesticides haven't disappeared, but Offutt's using less of them. It now employs automated weather stations and a sophisticated computer program to predict disease risk. The company tried the new system on 13 percent of the crop last year, targeting sensitive areas near homes where pesticide drift might be a problem. It cut pesticide applications by 30 percent.
This year the computer program is monitoring a third of Offutt's 10,000 acres in north central Minnesota.
The Minnesota fields offer a clear look at how Fargo-based Offutt, the nation's largest potato grower, is rethinking the way it uses pesticides. It's a response to consumer and environmental concerns, and to local residents who've complained for years about the spray drifting off fields. It may also make good business sense.
There's no question the old approach to pesticide spraying is no longer acceptable, company agronomist Nick David. "Farming is not gut feeling anymore. It's not, 'Well, I think this is going to happen', or 'this happened last year,'" he said. "Farming is very much real time, field by field."
If you've eaten french fries or potato chips, there's a good chance they came from potatoes grown on one of several R.D. Offutt farms. The fields here are monitored daily for moisture, plant growth and signs of disease. Potatoes are susceptible to a variety of insects and disease.
As he walked through some of those fields recently, David dug up a plant to check for signs of blight, one of the most damaging potato ailments. He sliced through the pencil sized root, exposing the plant's arteries that move nutrients and carbohydrates back into the potatoes.
He didn't find any blight, which is caused by fungal spores in the soil. The fungus will clog the potato arteries creating brown streaks in the root and the potato. It blocks the flow of water and nutrients. Worst case, the plant dies. Even a mild case will result in a less desirable potato, he said. "It won't make a nice french fry or nice potato chip."
David pointed to some "very white, beautiful looking potatoes" protected from blight by a fungicide sprayed a few days ago, leaving a white residue on the leaves.
The fungicide protects potatoes, but studies have shown the chemicals are toxic to aquatic species like frogs and the tiny invertebrates at the bottom of the food chain.
The spraying has raised the ire of local residents for years. This summer the Minnesota Department of Agriculture responded to those complaints with new pesticide best management practices aimed at reducing pesticide drift from potato fields, though David said Offutt already does more than the department recommendations.
Reducing pesticide use isn't just about the environment. It helps the company's bottom line too. "Last year we were able to take three or four applications out. This year we may be able to take three, four maybe five out," said David "The following year, if the weather is different and the disease pressure is higher, we may have to do more."
The farm is using more disease resistant potato varieties and altering its crop rotation to lower its pesticide use. Instead of growing potatoes on a field every three years, Offutt is moving to every fourth year.
Adding one year between crops can reduce the amount of disease causing fungus in the soil by 50 percent, David said.
Growing potatoes less often on each field, however, means more fields are needed, so Offutt is turning some former forest lands into irrigated potato fields. That's drawn criticism from environmentalists and state officials.
And even as some neighbors applaud the cut in pesticide use, they want to see more.
Local resident Carol Ashley has long been an outspoken critic of Offutt farms. She's a founding member of the group Toxic Taters. Standing next to an air monitoring device in the backyard of a friend's home in Park Rapids, Ashley explained how pesticide drift from potato fields affected her health, forcing her to sell her rural home and move 20 miles away.
She's convinced fungicides used on potatoes are affecting the environment.
"My yard was just covered with all kinds of frogs, and after they sprayed they were gone, fast, they just disappeared, all of them," she said. "There's no proof there, scientific proof. But you can't help but wonder when you're paying attention to things like that, what's going on?"
Despite years of outspoken criticism, Ashley is pleased by Offutt's effort to reduce pesticide use.
"I'm grateful that they're trying," she said. "They're paying attention finally, after what, 15 years we've been complaining about this? So even though we're grateful they're making this effort, and I think it's a step in the right direction, we don't think it's enough and we're hoping they can do more and we want to be sure people aren't being harmed."
Ashley wants to see Offutt farms move toward organic potato production, but she knows that can't happen quickly.
"Potato production can't be profitable without pesticides," David said, but the company is experimenting with bio-pesticides, natural defenses against disease. And there's no doubt anymore, he added, that potato farming needs to balance economics with environmental awareness and social acceptance if it wants to be sustainable.