CHURCHILL, Mont. — By the time Dan Dyk’s seed potatoes are stacked in the metal domes ubiquitous in the rolling hills of western Gallatin County, Mont., they’ve been sent through a rumbling amusement park of machinery.
Trucks dump the tubers onto a conveyor belt that runs them through more conveyor belts and metal rollers on a series of machines with obscure names common to the potato man—Even Flow, clodhopper, sizer. Dirt is sorted out, workers pluck big clods and crooked or damaged potatoes, and the surviving tubers ride to one of two places. Heavy potatoes—12 ounces or more—can’t be sold as seed, so they go to another truck and end up in the grocery stores. The lighter ones go the other way, to a machine called the piler, which drops them neatly in the cellar.
Dyk grew up in this valley. He knows the harvest’s industrial choreography as well as anybody, what goes where and why and how to make sure that the only thing entering the cellar are clean, good-looking seed potatoes.
This year, though, a devastating fungal disease forced him and many others in the valley to add an extra step: two sets of spray nozzles on the piler coating each tuber with a chemical meant to kill any remaining spores of that disease. It’s one with a history, the one that left the Irish hungry, one that Dyk wasn’t sure what to do about: late blight.
“This is the first time ever in the history of growing potatoes in this valley that we’ve ever had late blight show up,” he said.
They never thought it would. Late blight was something that happened to other growers in other places. But in August of this year, potato inspectors confirmed cases of it on several fields. Word spread fast, and soon airplanes dropped extra loads of fungicide; many planned to add that splash of chemical to each tuber’s trip to the cellar.
All of that work costs money, but it appears it prevented a drastic outbreak. It just raised the price of admission for a farmer to get his spuds into the cellar. And, when a disease like late blight shows up, folks like Dyk are pretty sure it’s worth it.
Nina Zidack, the director of the seed certification program for the Montana Potato Improvement Association, leads a team through three inspections of each seed potato field in the state each summer. The third inspection in the Gallatin Valley happened in August, and that’s when they found it.
“A farmer had noticed it first and pointed it out when we got there,” Zidack said.
Weird black spots had appeared on the leaves of a plant. The inspectors scraped some of the material onto a slide and put it under a microscope—that particular growers happened to have one in his shop—and, sure enough, it was late blight.
Late blight was first discovered in the United States in 1842. The most famous outbreak happened in Ireland in 1845 and caused the Irish potato famine.
Outbreaks have happened since, and some parts of the United States see it every single year. In Zidack’s time, it’s only been found in Montana four times, but never in Gallatin County.
It thrives in wet conditions, something this state isn’t known for. If left unfettered, it can wipe out entire potato or tomato fields in a matter of days, turning the vegetables black and rendering them useless.
Zidack is the person potato growers turn to for advice on how to deal with this sort of thing. She was born and raised on a grain and cattle operation in Montana and studied horticulture at Montana State University. She holds a Ph.D. in plant pathology from Auburn University and likes studying diseases. She gets to do a little bit of that these days.
“As far as I’m concerned, for me and my skill set, it’s the perfect job,” she said.
She runs the potato lab on MSU’s campus, where she and her staff study the starchy vegetables and act as regulators for the industry. The job is totally funded by fees paid by potato growers, and it certainly pays off when something like late blight shows up.
The disease can start in a number of different ways: wind-blown spores, splashing rain or someone walking through a wet field. Putting infected tubers in the ground is another way. That’s how it started in Idaho this year.
Jeff Miller, a potato researcher in southern Idaho, said it first showed up north of Pocatello. There was some late blight in 2014, and cull potatoes—the crooked or damaged ones workers pull off the line at harvest—buried in fields carried it over into this year.
A mild winter kept the disease from freezing and dying. In the summertime, out it came. It was first documented there July 10 and has since been found all over Idaho.
“This is one of the worst years we’ve had since the 1990s as far as the number of locations,” Miller said.
That outbreak is what Zidack points to as the likely source of it in the Gallatin Valley. Spores can be dislodged from a plant, move into a raincloud, take a long ride and get deposited on plants through a heavy storm. A set of heavy thunderstorms blew in from the south about two weeks before inspectors found it, and it’s possible the infection on Idaho’s fields got into the clouds and dropped out in Montana.
“That’s what we surmise,” she said. “We can’t prove that.”
All evidence she has points to that as the source. Once it arrived, it was time to start fighting it. It wasn’t long before everybody knew.
“Other places get late blight and boy, they just hush it up. They just don’t talk about it,” said Glenn Droge, a potato grower just down the road from Dyk, between Amsterdam and Manhattan. “Here, everybody wants to know.”
Inspectors kept walking through fields and kept finding it. For Droge, who grew about 380 acres of potatoes this year, it was a few spots on a few leaves here and there. It sounds mild, and with the work he did it became a non-issue, but hearing the prognosis was a shock.
“It was like a punch in the gut when you heard,” he said, standing behind a large shop at his place. In the driveway, a large white sign read “Droge Farms.”
Droge was born and raised on the farm, which has been in the family since the early 1900s. Four years at Dordt College in Iowa are all the time he spent away. He turned down a sales job with John Deere to become partners in the farm with his dad.
Now it’s him, his brother and his three sons. They grow malt barley and peas in addition to potatoes, which allows them to rotate their crops. Potatoes can only be planted in the same field once every five years.
Droge sells seed potatoes to farmers all over the country. At first, he worried late blight would make some of them look elsewhere for their seed this year. “We’ve all grown up thinking late blight is just a total disaster if it ever comes,” he said.
The next couple of days were a frenzy of emails and phone calls and research. They needed to know the best way to get rid of the disease. More fungicide appeared to be part of the answer. Stopping the disease before it got into the tubers was a priority, so most in the valley, if not all, started soon.
“I don’t know of a grower who didn’t in the next two days spray something on their fields,” Droge said.
Not every single potato escaped, though. Back at her lab in Bozeman, Zidack pulled one out and grabbed a knife to slice it open. Under the skin, brown splotches covered the yellow inside. Others had turned black.
She said there were only a few spots where the disease made it that far, but most farmers appear to have succeeded in stopping it early.
Routine fungicide regimens likely helped. Because potatoes are so susceptible to disease, farmers already spray them with several chemicals to prevent disease—like late blight’s pneumonic cousin, early blight. Some of those chemicals likely hindered late blight’s progress. Hot and dry weather through the rest of the month of August also hobbled the outbreak.
Still, many in the area are taking as many precautions as they can. Like Dyk, Droge had his potatoes sprayed with phosphorus as they went into the cellar.
“You’re so confident there’s nothing on these tubers, but it’s just kind of an insurance policy,” he said.
The insurance policies can get expensive fast. Droge guessed he’d spent between $25,000 and $30,000 on the extra loads of fungicide and the phosphorous spray. Lucky for them, they only had to fight the disease for a few weeks. If it had arrived earlier, like it did in Idaho, costs would have soared.
And, it turns out Droge’s buyers are pretty loyal. He started calling them as soon as he found out the disease had arrived and found most of them didn’t mind.
“So far everybody I’ve talked to has said, ‘Just don’t worry about it. We have to deal with it every year,’” he said.
Knowing that softened the blow to the gut he felt when he heard late blight was on his place. The problem seems to have been handled, just another chapter in the exciting life of a potato grower.
“Sometimes it’s not a good exciting,” he said.
Droge’s son Tim leaned against the shop and agreed with his father.
“It’s an emotional roller coaster,” Tim said.
The inspectors first pointed the late blight out to Dyk during the third summer inspection of his 250 acres, not long after they’d found it elsewhere. Two different spots—he called them blight holes—in two different fields, each about 6 or 7 feet wide.
“It was in a circle and every plant in that circle had lesions on them,” he said.
Black with a light green halo around them, the lesions were unlike anything Dyk had ever seen in person.
Dyk’s dad started growing potatoes in 1941. He grew commercial potatoes—the grocery store variety—until the 1960s, when they switched over to seed potatoes along with the rest of the valley.
“That’s when they decided that Montana, with our mountains and our isolation, would be great for growing certified seed,” Dyk said. “We raise disease-free seed.”
Dyk took over the potato operation from his dad in 1985 after getting a crop science degree from Montana State. Now he and his cousin, Doug, are partners in the business. They grow some grain, too.
After finding the blight holes, he ordered more fungicide and flagged them so they’d know where it was when harvest time came. They dug out the potatoes around those spots and loaded them into trucks, but left the blight holes there. He figures he spent about $30,000 on stopping the spread, and he’s confident he’ll be OK.
The phosphorous spray is the final step before potatoes settle into the cellar for the wait for spring shipping time. Each one gets two hits, one on each side. The full coat should be enough to stop the worst from happening.
“If you have late blight showing up in these potatoes, you’ve got nothing to sell,” he said, watching the piler do its work in the cellar. His buyers, too, are all over the country. Some have bought from the Dyks for decades.
He walked back out into the sunshine, moving fast and bouncing a little, naturally in rhythm with the rumbling machines. His eyes scanned the lot. Five cellars, and he has enough clean potatoes to fill them using the same mechanized amusement park that droned on in the background.
Behind him, after a couple of chemical splashes just to be sure, each spud’s ride ended and the pile grew.
Source: Bozeman Daily Chronicle