One lesson learned from longtime corn breeder Dave Nanda was very simple. As harvest approached, he wanted to see ears hanging, pointing downward. He reasoned that if stalks held ears upright in a tight position, they would dry more slowly. Plus, shucks and husks can collect and store water when ears are in an upright position, promoting ear molds and sprouting.

Dan Quinn, Purdue Extension corn specialist, visited the Corn Commentary field in central Indiana in mid-September. He agrees that if ears hang down after black layer forms on kernels, it can be positive for drydown. However, he points out that if ears hang over before black layer stage, it can be a negative.

“The connective tissue that holds the ear to the stalk is very thin,” Quinn says. “If something causes ears to fall and hang over, or if that process begins early, it’s possible that you can get a kink in that connective tissue holding the ear, like a kink in a garden hose.”

Should a kink form, it does the same thing it does in a hose, he notes. It restricts flow of materials. Before the black layer forms on corn kernels, they are still receiving sugars and other materials from the plant. These sugars contribute kernel size. Depth and plumpness of individual kernels is a huge factor when it comes to final yield potential.

Related:Black layer time arrives for 2024

“We don’t want anything restricting flow of materials to kernels while they are still actively accepting them,” Quinn explains. “Once the black layer forms and no more materials can enter kernels, then it no longer makes a difference.”

Black layer matters

That’s the point at which the situation reverses, and ears hanging down on a stalk become a plus for drydown, Quinn says. Once black layer is achieved, the plant is at physiological maturity. Then, the goal becomes reducing grain moisture content so harvest can occur as soon as possible.

Quinn pulled back shucks and checked ears on plants from both hybrids planted in the Corn Commentary field. He was looking for black layer at the tips of kernels, both in ears that were drooping and ears that were still erect. The thin, black layer forms as cells die and collapse, sealing off the kernel, he explains.

“For most kernels, the black layer was either formed or ready to form, especially on ears that had already fallen over on stalks,” Quinn says. “It didn’t appear that ears dropping over prematurely was an issue in this field.”

NEARING BLACK LAYER: When Dan Quinn examined kernels in the Corn Commentary field, he found that the black layer was either forming or about to form, indicating these plants are physiologically mature.

Across the rows:
What reports say about Midwest corn crop

While a strong yield is expected for the Corn Commentary field in central Indiana, what about across the Corn Belt? Will other areas produce high-yielding fields too? Will disease and mycotoxin be a problem this fall?

Here is a look at reports filtering in recently:

In Michigan. Kristin Poley, research and agronomy director for the Corn Marketing Program of Michigan, has recently gotten reports of ear molds that could contain vomitoxin. “But it’s nothing like last year’s widespread infection,” Poley reports. “While it is too late to apply a fungicide to protect against ear molds, we recommend growers are scouting fields to keep an eye on development.”

Recent work by Pierce Paul, Ohio State University plant pathologist, indicates that for fungicides to be effective in preventing ear molds, they need to be applied precisely at silking time in corn. He is developing computer models that could be used during the season to determine if weather conditions favor ear mold infections at silking, indicating fungicides would be effective in preventing these infections.

On another note, inconsistent corn ear development, an issue for Michigan growers in recent years, doesn’t seem to be a problem this year, Poley says.

A yield tour sponsored by CMPM in early August found tar spot statewide, prompting most growers to apply at least one pass of fungicide. “It was noticeable in some areas, but not at a level that would severely impact yield,” Poley says. “For both tar spot and vomitoxin, growers should be prepared to harvest infected fields first.” — compiled by Jennifer Kiel, editor of Michigan Farmer

In Illinois. “The 2024 growing season was somewhat unusual in Illinois, with overall conditions good enough to produce record-high corn and soybean yields. The September estimate of corn yield in Illinois is 222 bushels per acre, down 3 bushels from the August estimate. Soybean yield is projected to be 65 bushels per acre, 1 bushel less than the August estimate. These declines may reflect the increasing dryness in the state over the past weeks. With early-planted corn and soybeans at or near maturity, dryness will affect mostly late-planted crops.

“Dry weather during June limited the buildup of fungal disease inoculum, so although July was wet, most reports during grain fill were that fungal diseases were limited. An exception in some areas was tar spot disease. If the tar spot-infected crop matured while it still had a considerable amount of green leaf area, it likely filled kernels, with little loss from the disease. Applying fungicide probably made leaves healthier, but may or may not have increased yield enough to pay for treatment. We can only know if it did if we have a way to compare treated and untreated corn.” — compiled by Emerson Nafziger and G.P. Fontes, University of Illinois Extension, reported in the Illinois Crop Bulletin by Farmdoc, Sept. 13.

In Minnesota. “The good news is southeastern Minnesota looks really good, especially corn. The corn research studies I have there, primarily nitrogen studies, have really good yield potential — 240 or greater. I think there’s going to be combines that are going to be going through the field that are going to hit 300 over there.

“We did do some SPAD meter readings at R1 on our sites over there, and 3 of the 4 sites looked like they were going to respond to split application of nitrogen. Interestingly, though, that the crop today in that region looks a lot better than it did at R1, and I think that’s pretty typical across southern Minnesota, because it was just so wet early throughout May, June and the first half of July.

“Unfortunately, south-central Minnesota does not look as good, as most people know. It’s quite variable, lots of drowned-out areas, dead spots, but there are some good corn and beans, and I’ve seen corn improve considerably here over the last three to four weeks in our area. But unfortunately, all these bare, dead areas are going to drag field averages down, so I would expect less than long-term average yields for corn.” — from Jeff Vetsch, a researcher with the University of Minnesota at the Southern Research and Outreach Center in Waseca, taken from UM Nutrient Management Podcast in September