(NEVADA, IA) — Planting season is essentially in the rear-view mirror across central Iowa, but the way the crop got into the ground will shape decisions all summer long. A stretch of cold weather and frost that zeroed in on April 22nd and 23rd, followed by rain, left a mark — crusting that pushed some growers to pull out the rotary hoe, and pockets of hail across western, northwest, north central and southern Iowa.
That’s according to Mark Storr, technical service representative with BASF, checking in from central Iowa as producers wrap up planting and turn toward in-season management.
“We’re rolling. Things are off to a decent start where people haven’t had weather impact their crop,” Storr said. “It’s time to be thinking about the rest of the season as we put together management programs for our crops.”
With stand establishment mostly behind them, Storr said the next big decision for many producers is fungicide timing — and the science behind it starts with what plant pathologists call the disease triangle.
The Disease Triangle
“Plants are subject to getting any of those types of infections,” Storr said, ticking through the bacterial, fungal and viral possibilities. “Fungicides are for fungal infections, and they’re very effective at controlling those diseases.”
He pointed to gray leaf spot and tar spot in corn, plus frog eye leaf spot and septoria brown spot in soybeans, as some of the more common pathogens producers will be watching this summer. Every disease is unique, he said, but each one needs the same three ingredients: a susceptible host, the pathogen itself, and the right environment.
“The environment is obviously something we can’t control. We can’t schedule rainfall when we want it. We can’t schedule dewing mornings that keep leaves wet,” Storr said — making weather the wild card growers have to plan around.
Hitting the Window
That’s why timing — not reaction — is the name of the game. For corn, Storr said BASF zeroes in on the VT to R1 stage, from tassel emergence through early pollen shed.
“Corn is very good at protecting itself throughout the vegetative growing season,” Storr explained. “But once we shoot that tassel and we start to see silks, the plant turns into a reproductive activity… they don’t have the defense mechanisms that they once had.”
In soybeans, the call depends on the target. White mold pushes timing earlier — to the R1 to R2 beginning-bloom to full-bloom window — while broader foliar disease protection lines up with R3, when the canopy is essentially complete.
Storr noted BASF products like Veltyma and Revytek offer multiple modes of action, preventative and curative activity, and long residual control through the bushel-building window.
Don’t Scout for It — Watch the Conditions
One of Storr’s more important points for producers: when it comes to disease, what you see in the field is often a week or two behind what’s actually happening.
“Unfortunately, because of the long incubation period that a lot of our diseases have, you may have an infection in your field and you don’t know it until that disease becomes visible,” he said. Gray leaf spot, for example, can be active up to 19 days before it shows up.
Rather than leaning on scouting alone, Storr encouraged growers to use university-driven spore monitoring and predictive models — particularly for tar spot and white mold — and pair that data with conditions in their own fields. Lingering dew, extended leaf wetness and recent regional spore activity can all flag an earlier trigger pull, sometimes a week before true tassel.
“Be aware of your surroundings, and there’s a lot of resources online that you can check into,” Storr said. “If you have questions, visit your retailer or get in touch with your local BASF representative.”
As for the season ahead, Storr carries advice older than any model.
“My dad always used to say, when the crop looks the best, ‘man, this looks too good. I’m afraid I’m going to lose it,’” Storr said. “We’re pretty optimistic as growers and farmers, and we just hope and pray for the best.”
***AUDIO*** Hear the full conversation with Mark Storr from BASF below:
