The water stood on Corey Hillebo’s field for five days. By the time it drained he had two decisions to make and no reliable way to make either one.
Twelve inches of rain had come through. The bottom leaves of his corn were striping yellow, which might mean the crop had run short of nitrogen, or might mean the roots had sat in standing water too long to take up what was already there. Those two possibilities call for opposite responses, and nothing visible from the cab distinguishes them. He was weighing a fungicide pass the same week.
He called his agronomist and got the answer any operator would expect from someone who sells inputs for a living.
“Of course they want to sell it to me,” Hillebo said, “but I don’t know.”
Hillebo is a fifth-generation farmer from Polk City, Iowa, and co-host of the Farm4Profit Podcast. He was describing his own week out loud, on a recording made at TechHub Live in Des Moines with Tanner Winterhof and two founders whose companies exist to answer exactly that kind of question.
The Conflict of Interest Tanner Winterhof’s Show Put on the Table
Tanner Winterhof, co-founder and CEO of Farm4Profit Media, worked 15 years in agricultural lending before he moved into media. The uncomfortable question surfaced early in the episode he hosts. How does a grower validate the information when the person telling him his spore counts are high is the same person selling the fungicide?
Kristine White, co-founder and CEO of Spornado, said that question generates some of the most positive feedback her company gets. Her product sends a physical sample to an independent laboratory, and the grower can ask to see the lab’s report. The recommendation arrives from somewhere other than the sales pitch.
That separation is the actual product. Everything else is plumbing.
Catching a Corn Disease Two Weeks Before Anyone Can See It
Spornado’s hardware is deliberately unimpressive: a solar-powered air sampler on a wind vane, driven into the ground on a post. Inside sits a cassette that traps airborne fungal spores around the clock.
The grower or agronomist swaps that cassette weekly and puts it in an overnight courier to a partner lab, where it undergoes DNA analysis targeting up to four diseases at once. Results come back within 24 hours through a portal that can push text alerts.
White’s company grew out of indoor air-quality work. She and her colleagues had been sampling spores inside buildings for years when an input company called asking for something a farmer could put outside. Nothing existed. The sampler they built came from that phone call, and White kept the intellectual property because the company that asked for it didn’t want to pay for all of it.
The turnaround runs about 12 days end to end. What the grower buys with those 12 days, White says, is a warning that arrives more than two weeks before anything shows on the crop. Fungicide performs better as a prevention than as a rescue, so the lead time is the whole point. She put the cost at roughly $2,000 for a season of corn covering four diseases across 10 weeks, with one sampler per 100 to 200 acres in row crops.
Southern rust reached historic levels across Iowa in 2025 and contributed to reduced yields, according to Iowa State University plant pathologist Alison Robertson. It showed up in mid-July rather than late July, and it landed in a stretch when precipitation ran two to three times higher than the year before. Leaf wetness averaged 12.5 to 14 hours a day. Robertson’s guidance on timing is blunt. Applications at silking usually reduce the disease best.
White remembers the phone call. A client saw 20,000 southern rust spores in a region that had never had the disease and asked whether the test was broken. The lab re-ran everything, confirmed it, and called back to say the number was real. By mid-August the fields had caught up with the data.
The more interesting capability is still in research. Because the cassette captures the spore itself, the lab can test it for the mutations that confer fungicide resistance. White described a three-year study with the Ontario government on FRAC group 11 resistance. Every apple scab sample came back resistant. A service that tells a grower which product will fail is worth more than one that only tells him when to go. Resistance also builds faster when growers spray for diseases that aren’t there, so knowing when to skip a pass protects the chemistry itself.
Why a Satellite Needs a Deliberately Underfed Check Strip
Jackson Stansell came at the same problem from the nitrogen side. His company, Sentinel Ag, grew out of research at the University of Nebraska-Lincoln and began in fertigation, which pumps fertilizer through center pivots. It now sells decision support for nitrogen and water across corn, cotton, potatoes, grains and forages at $5 to $13 an acre, depending on tier.
Imagery on its own has a timing problem, Stansell said, because by the time a satellite can see nitrogen stress in a corn canopy the yield is usually already gone. His answer is a calibration trick: farmers place high-nitrogen and low-nitrogen check plots inside the field, the low one running about 30 pounds behind everything else. The overfed plot shows what the crop could do with unlimited nitrogen. The underfed plot starts slowing down before the rest of the field does, which makes it a canary. Together they give a three-point reading that tells the platform whether nitrogen is genuinely the limiting factor or whether something else is turning the crop yellow.
It handles Hillebo’s problem directly. If the crop can’t take up more nitrogen, the fed plot won’t outperform the starved one, and no recommendation comes. Stansell says the reverse happens too: customers have walked fields that triggered a recommendation and found no deficiency they could see anywhere in the canopy. The company reports that its on-farm validation trials produced a $23-per-acre profit improvement and a 25% gain in nitrogen use efficiency.
What Tanner Winterhof Means by Better Decisions Before the Check Clears
Neither founder claimed the technology replaces walking the field. Stansell said there is too much context in agriculture to automate the judgment away, and that he thinks about farmers the way he thinks about his own job: bring in people who are good at what you aren’t.
White reached for a plainer comparison. You can look up your symptoms online and get a credible answer, and you’re still going to see the doctor.
The direction the hosts pushed toward instead was pooled information. If dozens of samplers were reporting across a region, a grower could watch a disease move north through neighboring counties and get a plane in the air before it arrived. White said that already happens in a small way in Manitoba, where potato growers, input companies and processors agreed among themselves to share results, and a provincial agronomist issues an anonymized alert when late blight turns up.
Farm4Profit Media has run on one line since Tanner Winterhof and his co-hosts started it: make better decisions before you spend the money. A spore count and a deliberately starved check strip are unglamorous ways to do it, and they share a quality that’s rarer in farm data than it ought to be. Neither one arrives attached to an invoice.
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