Tar Spot

Iowa Farmer Battles Today's Pests While Eyeing Tomorrow's 'Mean Sixteen' Threats

Fri, 12 Dec 2025 18:52:50 GMT

For Worth County, Iowa, farmer Sarah Tweeten, the list of high-priority agronomic threats isn’t a political abstract — it’s a harsh reality she deals with every season.

Farming with her parents, Brian and Julie, and her uncle Roger, Tweeten has been steering the partnership toward more resilient cropping practices since joining the operation in 2021. This includes shifting from conventional tillage to strip tillage and splitting nitrogen applications.

The changes are part of a broader mindset: Protecting yields today from weeds, disease and insects while aggressively preparing for the next generation of agronomic threats. This forward-thinking approach is what led Tweeten to Washington, D.C., earlier this week as a Farm Journal Foundation farmer ambassador to help introduce a new report: “ The Mean Sixteen: Major Biosecurity Threats Facing U.S. Agriculture and How Policy Solutions Can Help. ”

Today’s Battles and Tomorrow’s Warnings
Researched and developed by Stephanie Mercier, PhD, the report takes an in-depth look at 16 significant pest issues U.S. farmers face now or could realistically in the future.

Tweeten is already battling a couple of the problems that underpin the urgency behind the research. For example, Palmer amaranth (pigweed) is gaining ground in her fields and across Iowa. The pervasive broadleaf weed can drastically reduce yields, with studies showing corn yield reductions between 11% and 91% and soybean yield reductions of 17% to 68%.

“We’ve struggled with pigweed as it continues to establish more resistance to our herbicides in our toolkit,” Tweeten says.

Two additional agronomic issues the report details include:

1. Asian Soybean Rust. First detected in the U.S. in Louisiana in 2004, this fungal disease has spread to southern states like Georgia and Mississippi. Scientists warn that warming winters could enable its migration to the Midwest, adding to existing disease pressures.

2. Corn Ear Rot. It can lead to aflatoxin production, making corn unmarketable and posing risks to humans and livestock. Aflatoxin is an issue Pickens County, Ala., farmer Annie Dee says is an ongoing problem for corn growers in her area.

“If we have aflatoxin, it can be impossible to sell the corn,” says Dee, also a Farm Journal Foundation Farmer ambassador.

A more recent threat she references is the impact of Highly Pathogenic Avian Influenza (bird flu) on local poultry farms.

Since January 2022, HPAI has been confirmed in a commercial or backyard poultry flock in all 50 states.

(USDA)

“An important market for us is poultry feed meal, so that’s a constant worry. The trickle-down effect is if we can’t move our corn then we can’t meet our financial obligations,” Dee adds.

Despite agricultural R&D offering a high ROI — $20 in benefits for every $1 spent — the Farm Journal Foundation report notes public funding for ag research has been declining over the past two decades.

“Farmers urgently need sustained support for aflatoxin research and prevention because these risks threaten our yields, our markets and the trust consumers place in American agriculture,” Dee says.

U.S. public spending on ag research and development has been falling for two decades.

(USDA-ERS)

African Swine Fever Has ‘Devastating Potential’
Looking to the future, Tweeten says she is concerned about African swine fever (ASF) and its potential to impact crop farmers as well as hog producers. The highly contagious swine disease hasn’t been detected in the U.S. mainland, but it isn’t far away. ASF has been confirmed in the Caribbean countries of Haiti and the Dominican Republic, roughly 700 miles from Miami, Fla.

“Being a farmer from Iowa, where we have probably eight times the amount of pigs as we do people, an outbreak of ASF would be just devastating to our state,” Tweeten says.

Hogs are among the biggest customers for the corn and soybeans Tweeten and her family grow. If African swine fever were to shut down hog production or exports, it wouldn’t just be a blow to livestock producers – it would hurt the entire agricultural community, she contends.

Read about 5 livestock diseases that could impact U.S. food security and economic stability.

Food Security Is National Security
When it comes to justifying funding for ag research, Tweeten knows there’s competition for every federal dollar. But she believes agriculture deserves a front-row seat — not only because of its economic weight and impact on farmers, but because of its role in national security.

“There’s that argument that food security is national security,” she says. “If there’s one thing COVID made us aware of, it’s that a disruption to our food chain can be terrifying, quite frankly.”

The pandemic made consumers and policymakers more aware of supply chain vulnerability. In 2020, the shock to the supply chain came from a human disease and logistical bottlenecks.

(Sarah Williams Photography)

Next time, Tweeten says, the disruption could just as easily come from animal or plant disease — whether African swine fever in hogs, Asian soybean rust or some other pathogen in crops. She worries about scenarios where farmers could face a fast-moving disease or crop pest while critical tools are still hung up in regulatory delays.

Her message: Farmers need a full toolbox, not one that’s half-built by the time a threat arrives.

“Ag needs to be in a good position when these sorts of emerging diseases and pests come into the country,” she says, “to have the tools in our toolbox ready for farmers to pull out.”

About the Farm Journal Foundation
The Farm Journal Foundation is a farmer-centered, non-profit, nonpartisan organization established in 2010. It works to advance agricultural innovation, food and nutrition security, conservation, and rural economic development.

Southern Rust Set To Take Big Bite Out Of Midwest Corn Crop?

Wed, 27 Aug 2025 21:06:37 GMT

If one picture is worth a thousand words, then the video Iowa farmer Dan Striegel shot last week must be worth thousands more. In the video, Striegel is shown harvesting a field of emerald-green corn enveloped in a cloud of orangish-red southern rust.

“We were just getting that field opened up, and I looked over and saw that dust boiling up out of the chopper, so I shot the video,” Striegel says.

Southern Rust? Never heard of her.
What Cheer, Iowa. USA. #pftour25 #harvest25 pic.twitter.com/tiIsUc2CHl
— Dan Striegel (@djsinseia) August 21, 2025

To date, Striegel’s video has garnered more than 48,000 views on X, formerly Twitter.

“We’re in southeast Iowa, Keokuk County, and I think the southern rust is as bad here as it is anywhere,” Striegel adds. “Every field you walk in, if you’re wearing a white T-shirt, you’ll come out of there red.”

A Red Path Of Disease Mars The Midwest

Expect to see more red T-shirt-clad farmers walking out of cornfields across the upper Midwest, based on what the Crop Protection Network (CPN) southern rust map is showing.

The CPN continually updates its online, interactive map showing the counties by state where southern rust infections are confirmed. Now, in late August, the counties look like red steppingstones. They form a checkered path from southwest Michigan through northern Illinois and Indiana, into southern Wisconsin, across all of Iowa and nearly two-thirds of the way across Nebraska. Eastern South Dakota is also lit up with a string of red counties, as are parts of southern to central Minnesota.

The amount of southern rust present in the upper Midwest is worrisome to Ken Ferrie, Farm Journal Field Agronomist. In severe cases, the disease can wipe out 45% of the yield potential in a field, according to the CPN.

“At most, one in 10 growers in northern Iowa and Minnesota have seen the kind of southern rust some of them are seeing this year,” says Ferrie, who was working last week with corn growers in both states.

“It was a problem in probably eight out of every 10 fields I was in, and they’d all been sprayed at least once,” he says. “Minnesota has a corn crop that’ll knock your socks off – yield potential of 250, 270. I encouraged every grower to spray their field a second time except for two fields. One had been knocked down by hail, and the other had a hybrid that was clean.”

I spoke with a good friend of mine from Iowa yesterday that is an agronomist and farmer. He said the southern rust in corn across Iowa and much of the Midwest will take 9 to 12 bushel/acre off corn yields on average from what his team and himself are seeing. pic.twitter.com/Ad1VJ9oQBg
— Captain Cornelius1 (@ISU145) August 26, 2025

Hybrids Have Little To No Resistance To Southern Rust

A combination of early-season moisture, heat and wind formed the perfect storm for southern rust this season, allowing the disease-causing fungal spores (Puccinia polysora) to move from southern climes up to the Midwest, according to Kurt Maertens, BASF technical service representative for eastern Iowa and western Illinois.

“We’ve seen it all – southern rust, tar spot, northern corn leaf blight, gray leaf spot. Our corn has been inundated with all these fungal diseases, and we started seeing them early,” says Maertens.

If there’s a silver lining to southern rust, it’s that it does not overwinter in corn residue like tar spot does. But like tar spot, southern rust takes advantage of hybrids that have no built-in resistance. For many growers, that was an Achilles heel this season.

“When you’re dealing with a 117-day hybrid like they grow in southern Illinois, Tennessee, and Kentucky, you don’t grow corn that doesn’t have good southern rust resistance, because they deal with it every year,” Ferrie notes. “When you move to Minnesota, and you’re planting 102- to 95-day corn, you’re probably not going to find hybrids with southern rust resistance.”

Striegel says that was true for his neighbor’s cornfield, which he custom chopped for silage. “That field had two hybrids in it, one was worse than the other, and the field had been sprayed with a fungicide,” he says.

He adds that he also sprayed his own cornfields with fungicide, but they are still inundated with southern rust.

“We’ve had southern rust before, and it’s not usually something we have to worry about, but this is really bad,” Striegel says. “I’m standing on my deck looking at the cornfield next to my house, and you know, all of the leaves from the ears down in that field are covered with it.”

Southern rust is real in eastern Nebraska. Fungicide 3 weeks ago, 2nd app today with some potassium acetate pic.twitter.com/WZubU6IBwz
— Trent Mastny (@TrentMastny) August 21, 2025

How Late Is A Fungicide Application Still Worthwhile?

Ferrie says the fields he scouted last week were at late R3 to early R4 and had already been sprayed with fungicide at least once, but the disease was rebuilding.

“Any field where farmers had sprayed two weeks previously, the southern rust and northern corn leaf blight, to a lesser degree, were coming back, especially the southern rust. It was resporating,” he says.

The intense disease pressure from southern rust, tar spot and others have kept fungicide use at high levels this season, despite poor commodity prices.

“Because of that [amount of disease pressure], we have seen increased demand for our fungicides this year,” says Maertens, who encouraged customers to get applications made at the beginning of tassel.

Maertens says he has fielded a lot of questions this summer from farmers, asking how late they could go with a fungicide application and still benefit.

“Our recommendation is to get in front of disease,” he says. “Generally, we stop applications before we get to dent (R5). That’s not to say a later application can’t have some benefit, but our best results have been before infection was able to take place.”

Southern rust is a yield enemy farmers routinely face in the Southeast, reports corn yield champion Randy Dowdy, Valdosta, Ga. He participated in the Pro Farmer Crop Tour last week and said on U.S. Farm Report he believes many Midwest farmers still have time to address disease.

“We need to implore the fungicides, the technologies out there and get after it and protect this crop, especially that crop that still has not reached dent,” he says.

Farm Journal Field Agronomist Missy Bauer likes to see farmers complete their fungicide applications on the front side of dough (early R4). “Once we get to early dent, I think it’s a little more challenging to get the payback consistently, though we’ve applied at early dent (R5), and seen a nice response,” says Bauer, who is based in south-central Michigan.

Under the tough disease pressure farmers are facing this year, Bauer is telling growers to scout fields and evaluate what growth stage their crop is in before they walk away or pull the fungicide trigger one last time.

She adds that farmers need to check the label to make sure the product used is able to address southern rust effectively. She describes these as “Cadillac” products containing the newest chemistry.

“When it comes to some of these diseases, especially southern rust and tar spot, I do believe a little bit of a Hail Mary pass can be effective,” she says. “Will it be as effective as an application you could have made on a more timely basis? Well, no, you could have made more money doing it timely, but you’re still protecting bushels and gaining ROI at the end.”

Ferrie adds that farmers might want to do the late-season fungicide application to keep their corn crop standing until they can put their harvest plan in place.

“Be doing the push test to check stalk quality,” he advises.

Southern Rust/Silage Alert!!

Southern Rust has been aggressively advancing in many fields, especially those without a fungicide treatment. In some situations the plants are shutting down prematurely and plant material is senescing rapidly.

While we typically want to get down… pic.twitter.com/aK3hGgZE19
— Pioneer Troy (@deutmeyer_troy) August 26, 2025

Striegel says some of the farmers around him are heading to fields to harvest their silage corn sooner than later, because of standability concerns. “Some of this corn got planted early, and we had a lot of heat. The crop matured quickly, and the diseases are kind of shutting it down. It’s just dying out, and guys are going to go get it,” he explains.

That’s the strategy Ferrie encourages farmers to use in regular production corn, too.

“Harvest the fields most at risk first. But if a field of corn goes down, go combine the fields where the corn is still standing and come back to that one later,” he recommends.

The reasoning is you don’t want to risk more corn going down while you’re harvesting the field of corn that already has.

“While I was driving through Iowa last week, I kept thinking that if I built corn reels to pick up down corn I’d bulk up my inventory, because I know where they’re going to get used,” Ferrie says, only half joking. “Yes, harvesting corn at 25% moisture is expensive, but down corn will kick your butt.”

Your next read: Revenge Applications: Why They Don’t Work, Cost You Money and Bushels, and Are Frankly Illegal

How Pro Farmer 2025 Crop Estimates Compare and Contrast With USDA Expectations

Fri, 22 Aug 2025 20:32:51 GMT

As more than 100 crop scouts traversed dirt roads and two-lane highways, stopping dozens of times to sample corn and soybeans in seven Midwest states, they gathered insights to answer the question on many farmers’ minds this week: How would the Pro Farmer estimates compare to the numbers USDA-NASS released August 12?

The answer: Pro Farmer found a big corn crop but one that’s currently positioned to average 182.7 bu. per acre – 6.1 bu. below USDA’s 188.8 bu. projection.

“When we put the yield estimate out, it comes with a plus or minus 1% for corn and a plus or minus 2% for soybeans, and that’s because we know things can change yet,” says Chip Flory, host of AgriTalk and lead scout on the western leg of the tour.

“The other thing is the yield models that we use give us a range, and then, based on conditions, we can move within that range with the yield estimate that we’re going to pull,” he adds.

With that perspective in play, here’s how the Pro Farmer and USDA estimates compare:

Pro Farmer Corn Estimate (+-1%): 16.042 to 16.366 billion bushels; 180.9 to 184.5 bu. per acre average
USDA Corn Estimate: 16.7 billion bushels; 188.8 bu. per acre average

(ProFarmer)

Disease Pressure Across The Midwest Is Concerning
The 2025 growing season has been marred by heavy disease pressure in many of the corn and soybean crops Pro Farmer scouts evaluated this week.

It was an issue Lane Akre says showed up repeatedly in corn and soybean fields from the get-go, as tour scouts fanned out to check 2,000-plus fields across seven states: Illinois, Indiana, Iowa, Minnesota, Nebraska, Ohio and South Dakota.

“We know disease can speed up the maturation of plants, making it difficult to keep them healthy long enough for optimal grain fill before harvest,” says Akre, Pro Farmer Economist and lead scout on the eastern leg of the tour. “We are concerned diseases like southern rust and tar spot could negatively impact corn yields in some of these states during the next few weeks.”

Soybeans Could Be the Star of the Season
USDA’s August estimate for the national soybean yield average is just slightly above what Pro Farmer scouts found in fields this week. Pro Farmer places the soybean yield average at 53.0 bu. per acre, with a total crop size of 4.246 billion bushels

By comparison, USDA expects soybeans to average a record high 53.6 bu. per acre, with a total crop of 4.29 billion bushels.

Pro Farmer Soybean Estimate (+-2%): 4.161 to 4.330 billion bushels; 51.9 to 54.1 bu. per acre

“One of the questions heading into the tour was whether the soybean crop could live up to the lofty expectations a lot of people have for it, and we found that it does,” Akre says. “There’s a massive crop out there in fields. We’re just hoping it can hold on until harvest – and outpace the disease pressure out there – to deliver on those big yields.”

Corn and Soybean Yield Summaries
Pro Farmer and AgWeb reported extensively throughout the tour — the highs and lows of each crop in each of the seven states. Here are summaries from each state. Click on the links to learn more details.

Illinois: Scouts reported an Illinois corn crop that looked lush from the road, but once they picked ears and pulled back husks, most described finding an average to above-average crop – not the record yield estimate USDA reported on August 12.

“The Illinois corn crop just wasn’t what we’d hoped,” Akre says. “USDA is anticipating a 1.7% jump from a year ago, and we’re actually down 2.2%.”

Indiana: Wet conditions from rain, fog and heavy due is causing some unevenness in Indiana corn and soybeans. Still, the state’s corn crop posted a yield number that came in 3.35% higher than its 2024 number.

From disease pressure to too much rain, some scouts found a solid soybean crop in Indiana, while other routes exposed extreme variability. Overall pod count numbers were down 2.30% from 2024.

Iowa: Scouts spent two days in the state gathering dozens of samples to gain insights and project yield estimates. Despite challenges from disease pressure, scouts reported a big corn crop with significant potential. Their estimates put the Iowa crop up 2.93% over 2024, and up 6.4% versus the three-year average.

“This Iowa crop has a very, very strong ear count, great grain inches — just a very consistent equation putting that corn yield together,” reports Emily Flory Carolan, Pro Farmer Crop Tour data consultant.

For soybeans, scouts found a massive crop, up 5.49% in the number of pods as compared to the 2024 crop.

Minnesota: The corn crop in Minnesota is currently heading for a record yield this season, if it can outpace disease pressure. Scouts recorded the longest grain inches in the corn there that have ever been measured in the tour’s history.

“That’s definitely what pulled up that yield average for us,” Carolan says.

Soybeans also show tremendous yield potential in Minnesota. Pod counts were up 20.38% this week versus 2024 counts, and up 19.9% versus the three-year average.

Nebraska: Adequate moisture is pulling up corn yields in the state this season, with some tour routes reporting 8% to 10% increases compared to 2024 and 2023. The much-improved corn yield estimates were a welcomed change, scouts say, after seeing corn there struggle in two back-to-back years of drought.

Soybeans also are promising big yield results, with pod counts up 15.0% this week over the 2024 estimate.

Ohio: Heavy rains last spring meant many farmers either got a late start to the growing season or they had to replant fields. The moisture extremes early on have resulted in considerable variability in fields from one end of the state to the other. Still, scouts say the Ohio crop has solid corn yield potential overall, citing possible records along some Pro Farmer Crop Tour routes.

The soybean pod factory in Ohio is going strong – with numbers up 4.66% this season over 2024 – but scouts caution a lack of late-season moisture is concerning. More rain is needed for the soybean crop there to finish well.

South Dakota: Based on USDA’s August crop estimates, scouts knew the possibility was there to uncover a big crop in South Dakota. Field estimates show record yield potential is possible , especially due to ample moisture this year that’s supported growth and development.

Soybeans might be an even better story in South Dakota this year. Pod counts came in at 15.9% above last year’s tour and well above the three-year average of 970.1 pods.

For more insights from the 2025 Pro Farmer Crop Tour:

Watch On-Demand: Pro Farmer Crop Tour Day 4 Results from Iowa and Minnesota

Watch On-Demand: Pro Farmer Crop Tour Day 3 Results from Illinois and Iowa

Watch On-Demand: Pro Farmer Crop Tour Day 2 Results from Indiana and Nebraska

Watch On-Demand: Pro Farmer Crop Tour Day 1 Results from Ohio and South Dakota

Iowa Corn Has High Potential, Illinois Crop Looks Average and Soybeans Shine in Both States

Wed, 20 Aug 2025 23:58:02 GMT

Bright orange is a great color for pumpkins but not so much for corn. Nonetheless, that was the prevailing color Brent Judisch reports seeing as he evaluated crops Wednesday morning in northwest Iowa’s Harrison County.

“Our first six or seven samples were terrible with southern rust,” says Judisch, a Pro Farmer Crop Tour scout and Iowa farmer. “We saw three fields in a row that were actually gross. I walked out of them just covered with it. After that, while we’ve seen it all day, it’s been more in the lower leaves and not nearly as drastic.”

Chip Flory, lead scout for the western leg of the tour, says the northwest Iowa crop is the best and worst he’s ever seen.

“In the snapshot that we took of it, and the measurables we saw in the field today, it is the best corn crop,” Flory reported during the tour’s nightly live broadcast.

But the disease pressure in the Iowa crop has Flory spooked.

“Disease pressure is putting a lot of bushels — a huge number of bushels — at risk,” he adds. “You can take 20, 30 bushels off of corn yield with what southern rust can do to the crop, even at this late stage in the game. It’s a dangerous crop that we’re looking at out here right now.”

Chip Flory says he was surprised to see corn that was well into R5 (dent) in northwest Iowa. “I can’t tell if it was this mature because of pressure from the southern rust, or if it was because of higher nighttime temperatures at pollination,” he reports. “I am concerned about how much disease is out here, and what it’s going to look like in another week or two.”

(Chip Flory, Host of AgriTalk)

Can The Iowa Corn Crop Still Hit A Record?
The Iowa corn results were a big shocker on Wednesday, given the amount of disease pressure scouts saw, according to Emily Flory Carolan, Pro Farmer Crop Tour data consultant.

“I would say all three districts were setting new records. They were consistently high in all measurements for corn in ear count, inches long and kernels around,” she says.

Carolan’s summary of the results scouts tallied in Iowa revealed some high yield estimates, despite the disease pressure:

*District 1 was 197.89 bushels, up 12.06% versus 2024 and up 9.89% versus the three-year average.

*District 4 was 207.25 bushels, up 5.82% versus last year and up 14.01% versus the three-year average.

*District 7 came in at 195.03 bushels, up 1.80% versus 2024 and up 6.35% versus the three-year average.

(ProFarmer)

Flory is concerned southern rust will impact standability in the Iowa crop, which he says is starting to dent in areas, and cause some of it to go down.

“I’d want to keep an eye on the stalk condition of this crop, because if this disease pressure continues, farmers are going to want to get out and prioritize fields for harvest before we get there,” he adds.

Illinois Corn Crop Looks Average
Scouts report the Illinois corn crop appears lush from the road, but once they walked out into fields, picked ears and pulled back husks, most described finding an average crop.

“We’ve seen some good corn, we’ve seen some average corn and we’ve some stuff that’s got a long way to go,” tour scout Jake Guse told U.S. Farm Report’s Tyne Morgan on Wednesday morning.

That perspective played out in the total results tallied and shared during the nightly tour meeting. Illinois corn averaged 196.19 bushels per acre, down 2.24% from last year but up 1.72% from the three-year average.

(ProFarmer)

Ninth and final stop 4 miles North of Roseville, IL. Population was very good at 34,000. The yield is 213. Kernel depth is just under a 1/2 inch. Some disease was showing up here including tar spot! Soybeans had 1778 pods in 3X3 area. #oatt #pftour25 pic.twitter.com/xAcDSxJL0q
— Darren Frye (@Frye_WSS) August 20, 2025

USDA-NASS estimates released August 12 project the Illinois corn crop will come in averaging 221 bu. per acre for the state, up 4 bushels over 2024.

That’s outside what Guse’s expectations are for the state.

“As you’re driving along the road, you can see ears that are already tipped over. I just don’t see it reaching [USDA’s projection],” he says.

Lane Akre, Pro Farmer economist and host for the eastern leg of the tour, agrees with Guse. He reports pulling several samples of corn that exceeded 200-bu. per acre as well as one that only hit 143 bushels.

“The Illinois crop just wasn’t what we’d hoped,” Akre says. “USDA is anticipating a 1.7% jump from a year ago, and we’re actually down 2.2%.”

Akre’s leg of the tour went through three Illinois counties that are typically heavy hitters for corn yields: Bureau County, Henry County and Rock Island County.

“There’s really good dirt through that area, and the farmers there are very good at actively managing their crops and what they do with fertilizer, herbicide and fungicide,” Akre notes. “We saw some poor emergence and that might’ve weighed on the samples we took.”

Soybeans Could Be the Star of the Season
Soybeans offered a better yield picture for Illinois farmers than the corn crop, Akre notes.

“We didn’t have a single sample in the state that was south of 1,300 pods in a 3’x3' square. We saw a lot of pods and a lot of potential out there,” he says.

The average counts Illinois scouts recorded was even higher than what Akre found, with an average of 1,479.22 pods in a 3’x3' square area. That is up 4.24% versus 2024 and up 12.65% versus the three-year average.

(ProFarmer)

Iowa soybean results across the three districts were equally impressive.

“This year’s crop is better than last year by far,” Greg Lehenbauer, Pro Farmer crop scout, told AgDay’s Michelle Rook. “They’ve had adequate rain across this part of Iowa almost all summer long.”

#pftour25 Day 3. Stop 2 Plymouth Co. IA. #Soybean pod count 816. @AgDayTV @FarmJournal @USFarmReport pic.twitter.com/GgmulwJ8UI
— Michelle Rook (@michellerookag) August 20, 2025

Carolan’s data confirmed the excellent soybeans that crop scouts found on Wednesday in all three districts:

*District 1 soybeans: 1,279.25 pods, up 15.38% versus 2024 and up 15.05% versus the three-year average.

*District 4 soybeans: 1,376.15 pods, up 9.73% versus 2024 and up 13.63% versus the three-year average.

*District 7 soybeans: 1,562.54 pods, up 14.37% versus 2024, and up 24.66% versus the three-year average.

(ProFarmer)

While Flory is cautiously optimistic about the Iowa soybean crop, he says stem rot and sudden death syndrome is taking root in more fields and threatening yield outcomes.

“Some of the routes through southern and west-central Iowa have seen a tremendous amount of disease issue on the soybeans, so I’ve got a feeling it’s going to look a lot different in a week than what it does right now,” he predicts. “Now, if it was September 10, that’d be one thing. But it’s August 20, and there’s still time for those bean diseases to take some yield away.”

Flory’s sentiment about what fields revealed in Iowa was shared by scout Brent Judisch.

“What it’s going to come down to here in the corn and the beans is, does the crop mature faster than the disease moves, or will disease outpace the crop?” Judisch says. “We won’t know for sure for another two or three weeks.”

Watch On-Demand: Pro Farmer Crop Tour Day 3 Results from Illinois and Iowa

Watch On-Demand: Pro Farmer Crop Tour Day 2 Results from Indiana and Nebraska

Watch On-Demand: Pro Farmer Crop Tour Day 1 Results from Ohio and South Dakota

About the Pro Farmer Crop Tour
The Pro Farmer Crop Tour is taking place Aug. 18-21, 2025. Simultaneously, the tour follows an eastern and western route, with the two culminating in Rochester, Minn. Nightly meetings in each location review daily results, scouting observations and historical comparison data. Attend nightly meetings in person or watch the nightly broadcast online at AgWeb.com/croptour .

R5 Growth Stage Holds Hidden Yield Potential

Wed, 20 Aug 2025 16:08:48 GMT

As your corn crop turns the last corner of the 2025 growing season and heads for the finish line and harvest, there is still a lot of potential yield to be made or lost in the process.

The R5 growth stage (dent) – the next to last growth stage for corn – is one of those key times in the season where your management practices and Mother Nature’s cooperation up to that point can influence harvest outcomes.

Dan Quinn, Purdue University Extension corn specialist, explains the reason: kernel dry matter content in a corn crop at the beginning of R5 is only at roughly 45% of the eventual final accumulation.

Another way to look at that – there is still up to 55% of the kernel dry weight left to be accumulated by the crop, starch that can contribute significantly to grain fill and yield.

“Therefore, if significant environmental stress (drought, nutrient deficiency, etc.) were to occur during beginning R5, significant yield losses can still occur,” Quinn writes in this online article .

Many of the newer hybrids seed companies have developed are designed to add bushels by increasing the amount of starch in kernels, according to Ken Ferrie Farm Journal Field Agronomist.

“That’s one way we obtain yield increases without raising populations,” Ferrie says.

Keying Into The R5 Growth Stage
Michigan farmer Nathan Baker addresses the importance of R5, in his most recent video, posted to YouTube on Monday .

In the video (starting at about 24 mintues), Baker is evaluating his early-April planted corn, which is starting to reach dent (R5). Of his entire 2025 crop, he says it is the most advanced field of corn he has, noting there is some disease pressure present.

“That is northern corn leaf blight. You can see it started with a lesion here, and it has spread. There’s another one. I don’t like to see that…but there’s nothing drastic,” Baker says, pointing to some damaged areas on a corn leaf.

Baker says he used fungicide to rein-in disease pressure. In some fields, he made two applications.

(Nathan Baker)

Knowing the importance of late-season grain fill is a key reason Baker says he made the investment in applying a foliar fungicide some weeks earlier.

“That’s why it’s important that we … take care of these plants late in the season and keep packing that starch in there, giving it all the nutrients and the things that it needs. It’s why I still really, really want some rain, because we can still use it to help make this corn crop better,” he says.

Baker gives a shout out to his AgriGold agronomist, Wayde Looker, for the insights he learned about the R5 growth stage.

Look For The Milk Line In Kernels
As corn moves into the R5 stage, you can start to see a distinct line near the top of kernels, which is the milk line. This line indicates the division between the dry and liquid material in the kernel.

The R5 growth stage in corn can occur approximately 30 – 40 days following silking and is defined when nearly all kernels are ‘dented’ at the crown of the kernel and hard starch or solid endosperm has begun to form.

(Dan Quinn, Purdue University Extension Corn Specialist)

As kernels harden, the line moves from the top of the kernel down to where the base attaches to the cob. Keeping an eye on the milk line’s progression is useful to corn growers who cut crop for silage or are trying to determine when to stop irrigating. It’s also helpful for growers trying to determine how much time is left before the corn reaches maturity and will be ready to combine.

Quinn says corn moves through the early part of R5 quickly and then slows as it nears physiological maturity (R6, black layer). Overall, from the beginning of R5 to maturity is about 33 days:

3 days — from the start of R5 to the quarter milk line stage
6 days — from quarter to half milk line
10 days — from half to three-quarters milk line
14 days — from three-quarters milk line to black layer

Actual time to black layer may vary depending upon the hybrid and the environment. However, this is a guide that lets you know what to expect and help you plan for harvest, Quinn says.

Your next read: Understanding Ear Flex

Take Our Poll: What Problems Are Showing Up In Your Corn Fields?

Fri, 25 Jul 2025 17:32:30 GMT

‘Tis the time of year to be scouting for various diseases and pests and assessing how your corn crop is coming along. In addition to keeping a watchful eye for southern rust and tar spot, some farmers and agronomists have been surprised to find pollination issues. “ Overly tight tassel wrap ” went largely unnoticed until a couple weeks ago.

“It’s a situation where the tassels on some varieties, based on the growing conditions, were wrapped too tight. The pollen couldn’t get out of the wrap, which led to a poor start for the pollination cycle,” explains Ken Ferrie, Farm Journal field agronomist.

Farmers and agronomists have reported pollination issues due to tight tassel wrap in at least 10 states. Only time will tell how widespread the unusual problem impacted yields.

In addition to pollination problems, southern rust has now been confirmed in at least 15 states. With the recent heat, humidity and strong winds, agronomists are encouraging farmers to scout their corn fields, as conditions are ripe for the disease to spread.

Since late June, Ferrie has been closely monitoring tar spot reports in Illinois and working with growers to create and implement action plans for their specific fields to address the disease.

That’s why we want to hear from you. How is your corn crop faring? Click here to take our AgWeb poll , and let us know if you’re seeing pollination issues due to tight tassel wrap and/or if you’ve confirmed southern rust or tar spot this year. We only ask four questions, so it will take less than a minute to participate.

If You're On The Fence About Fungicide Use in Corn, Consider These 5 Questions

Wed, 23 Jul 2025 21:41:28 GMT

As Ken Ferrie evaluates disease challenges he sees in cornfields right now, tar spot comes to the top of his list of concerns.

“We’ve got a lot of areas that are picking up these 3-, 4-, 5-inch rains, and that’s where you’ll see tar spot really blast if and when it takes off,” says Ferrie, Farm Journal Field Agronomist.

The disease started showing up in central Illinois corn the last week of June this summer, similar timing to what occurred in 2021.

“Last time we had tar spot in June was in 2021, and it really butchered us before it got done,” Ferrie recalls.

While the disease is showing up in Illinois and a handful of other states, the impact so far has been low. But that could change quickly. Ferrie is especially concerned what will happen, now that pollination is almost over for most Midwest corn crops.

“It seems like after pollination, corn gives up some of its disease resistance,” he told Farm Journal’s Tyne Morgan and Clinton Griffiths during their recent podcast, Unscripted. Watch it here:

“The disease pressure really ramps up after pollination compared to pre-pollination, when that corn plant kind of switches to making grain versus being protective,” he says. “I do anticipate that we’ll see a lot more tar spot pressure here, especially in our wet areas, because of the heavy fogs, the humidity in the morning, the wet leaves.”

Charting Average Daily Humidity Can Help
Missy Bauer is also nervous tar spot could take off in Michigan fields this season. She is encouraging farmers to keep an eye on the average daily humidity levels for their area.

This is a humidity chart Farm Journal Field Agronomist Missy Bauer put together, showing what farmers in south-central Michigan, near Coldwater, can expect through July 31. Notice that the data is averaging below what the area saw in 2021 — a huge year for tar spot — but above what occurred in 2022.

(B&M Crop Consulting, Coldwater, Mich.)

“Universities have found when average daily humidity is above 75%, corn crops are at risk,” says Bauer, Farm Journal Field Agronomist and owner of B&M Crop Consulting, Coldwater, Mich.

You can find the average daily humidity information for your specific area online via Weather Underground and other weather station resources.

She says economic data is telling her that a single pass of fungicide at R1 will pay for itself in corn that’s at risk for tar spot. “The data is very supportive of making that first pass, no problem,” she says.

The same data shows a double pass of fungicide often delivers a return-on-investment (ROI), because so many of today’s hybrids build yield through depth of kernel fill. The second pass protects that later-season starch development.

Make sure to watch the brief video Farm Journal’s Matthew Grassi did with Bauer to hear her recommendations on when to apply fungicide to address tar spot, especially her strategy for when or whether to make that second pass.

For an added bonus, Bauer addresses what occurred in soybean fields this spring with the carbon penalty.

A No-Fungicide Decision Needs A Game Plan
Ferrie says he realizes some growers are struggling to make the call to apply fungicides this season, given corn prices.

If you’re still on the fence, he advises making some pre-season yield estimates based on ear counts to help you calculate where an application would help with ROI and where it might not.

In the process, he says to ask yourself these five questions:

1. How well did your crop pollinate?
2. What’s your ear count per acre versus your population?
3. How significant is your disease pressure?
4. Can you harvest the corn crop early, before it falls apart from disease and standability issues?
5. Are you able to dry the crop, if you have to harvest early?

The answers to those questions can help you start to predict what the end result at harvest is likely to be.

“You may have to reevaluate what your yield goal potential is, because if you gave it up at pollination, a fungicide application is not going to get it back for you,” Ferrie says, noting he had that conversation with a grower last week.

“He planned on spraying twice with a fungicide, and now, due to pollination issues, he’s going to only spray once,” Ferrie notes.

If you opt to not spray a fungicide, Ferrie says you need to consider making your contingency plans for harvest now, and you can tweak them as you get closer to running the combine.

“Evaluating your crop now will help this fall and also help you improve what you do next year,” Ferrie says. “Once you’re on the combine, there’s not much more evaluation you can do on a plant-by-plant basis.”

Flying High and Digging Deep — Precision Ag from the Sky to the Soil

Wed, 09 Jul 2025 19:48:24 GMT

Josiah Garber found tar spot lurking in one of his cornfields the last week of June. The southeast Pennsylvania corn grower says that was a first for his farm.

“I’d never found it in July before, much less the end of June. I think the pressure this year is going to be intense with all the moisture around,” predicts Garber, who’s based in Lancaster County, Pa.

Tar spot commonly overwinters as spores in plant residue. During the subsequent growing season, rain and high humidity can promote spores which can be splashed onto corn plants and then develop into what is often called homegrown tar spot.

Tar spot spores can also become air-borne in a field and blow into new fields.

How significant tar spot infections become in any given season depends on the disease triangle – the interplay between a susceptible host, a pathogen and the environment.

A Two-Pass Program Is In Place

Garber’s plan to address tar spot – along with any other disease pressure that’s present – is to make two fungicide applications 21 days apart. This year, the first one went on the crop with a ground rig just before tassel and the second application will be made right after tassel, which was underway last week.

“This is the first time we went with a fungicide application this early, but I’m glad we did since we found the tar spot,” Garber says.

For the past five-plus years, he has been investing in two fungicide applications annually, with both made post-tassel.

“We found that that pays, and once we saw that it would pay, it just became part of our program,” Garber told David Hula and Randy Dowdy during their latest Breaking Barriers with R&D podcast, available now on Farm Journal TV. This episode offers farmers some serious actionable insights to help improve ROI.

To achieve good coverage with the ground rig, Garber says he applies a fungicide/water tank mix at 20 to 25 gallons per acre.

“We’ve been working really hard on our applications, trying to cover below the ear leaf to get optimum performance,” he says. “That’s our goal.”

Droplet Size Impacts Coverage And Efficacy

The goal of getting fungicide placed in the crop where plants can readily use it is what Matt Crabbe shoots to achieve with aerial applications. He typically uses 2 gallons of water per acre as the carrier, depending on the products being sprayed.

“I hear a lot of times people talking water, water, water, but a lot of water can go to the ground and take the product with it if you’re not careful,” cautions Crabbe, owner of Crabbe Aviation, with locations in North Carolina and Virginia.

“Because you’ve got bigger droplets with the plane, you’re putting out a little more volume, and it’s not going to necessarily stay with the plant like I found it does with the lower volumes,” he tells Dowdy and Hula.

To help ensure product stays on plant leaves, Crabbe usually applies products like foliar fungicides at 3’ to 8’ above the crop canopy, maintaining a consistent speed of between 150 and 160 miles per hour.

“I try to keep the application in that range, because our test results show that sets up the droplets at the right size for optimum coverage,” he says.

Get As-Applied Maps For Your Records

Dowdy asked Crabbe whether he provides customers with as-applied maps for their reference and records, post product applications.

“You know, there’s a lot of people that want to overlay yield maps, and then some people just want to trust but verify the good old Ronald Reagan way,” Dowdy says.

Crabbe says modern technology is making as-applied maps easier to provide to growers than in previous years.

“If you place an order on my website, I can press ‘done’ when I finish spraying a field and the system will give you a look at the as-applied map,” he explains.

Crabbe recommends farmers ask their aerial applicator directly about their mapping system as many now have digital platforms where you can get a password to access your specific maps and view application details immediately after completion.

Hear more about getting the biggest bang out of your fungicide buck from Dowdy and Hula on YouTube at Breaking Barriers With R&D: Flying High and Digging Deep — Precision Ag from the Sky to the Soil and on AgriTalk, with Host Chip Flory:

Your next read: Is 600-Bu.-Per-Acre Corn in the Cards This Year for David Hula, the Reigning World Record Holder?