Agronomist sees wide corn yield variability

MACOMB, Ill. — It’s been a “roller-coaster” growing season for Illinois corn.

Brad Mason, Pioneer field agronomist, said there’s a lot of variability in corn across his region that’s bordered by I-80 to the north through McDonough and Fulton counties in the south.

Here’s what Mason had to say during an Aug. 31 interview at Pioneer’s Farm Progress Show exhibit.

What are you seeing in general in western Illinois corn fields?

“Areas across the board are variable. In the spring, my northern area was dry, my southern area was wet with some of the last planting dates being the first couple weeks of June where they are normally April and May. With the excessive rain on the south side of my geography, really Galesburg south, they are seeing excessive nutrient loss from excessive rain, things like that, where we’re seeing cannibalizing of corn stalks. We’re seeing variability in predicted yields in our yield counts.

“As I go north in my geography where they were drying and had timely rain the crop looks pretty good across the board as long as there wasn’t wind across that area. There were several storms here around the anniversary of last year’s derecho and a couple last week that have made things look interesting across that area.

“Every field is going to be a different experience.”

—  Brad Mason, field agronomist, Pioneer

“On the corn crop specifically, I’ve kind of told people to be ready for a roller-coaster. Every field is going to be a different experience. Same products, different environments are going to drastically change what you see. Those who maybe aggressively managed nutrients I would expect to see maybe get a little better payoff than those who didn’t.

“With the growing season that we had it didn’t make us think that necessarily was going to be the way it was going to go, but just the sheer cannibalization of stalks, a lot of plants are shutting down from this last couple of weeks of heat.”

Variability is also apparent in cornfields across the road from one another. Obviously the weather was the same on either side of the road. Is that attributed to the hybrid, fertility management or other factors?

“There are hybrid things. We talk about products that do well with wet feet versus not, products that have certain agronomic traits that don’t benefit from late nitrogen, things like that that can hang on. However, a lot of times in that specific area on the southern region of my area it comes down to the lay of the field. If a field doesn’t have any roll you’re typically going to take water and having that it’s really going to struggle. So, those that can make that in-season adjustment typically reap the benefits of it historically from what I’ve seen.”

The U.S. Department of Agriculture is sticking with its projection of a record average corn yield in Illinois. Do you see that reaching fruition in western Illinois?

“I can’t comment on their numbers specifically, but I can say across my geography there’s really, really good corn, like 2017, 2018 levels, and there’s corn nowhere near that. So, that’s going to be the big question mark as you look at it.

“My argument with most people is typically everybody goes to 2019 and those wet years. We don’t have zeros in fields this year. That’s the nice thing. I think back to grade school and zero is an average-killer. You get a zero on an assignment and you can never get an ‘A’ again. Not having those zeros in a field is very beneficial.”

What have you observed in terms of corn diseases this year in your region?

“There’s also a fair amount of disease pressure on the corn side. There’s a lot of tar spot that we don’t historically see really setting in until now, and it set-in in July because of those foggy cool mornings that we were seeing the first two weeks of July. We are at the end of our fungicide window — 14 to 21 days of efficacy. That disease picked back up in August and really ran rampant in some geographies and unfortunately has taken some crop to the ground.”

Has there been any insect pressure this growing season in western Illinois?

“I haven’t seen any across my geography. We’ve really been very fortunate. Typically with a dry June you see more rootworm beetles and things like that. There are more than I would normally see in corn-on-corn fields, but for the most part it’s below threshold. Every environment is completely different. Those are the ones that I’ve seen.

“Overall, Japanese beetles seem to be down in my geography this year with really low numbers. There is a fair amount of armyworm pressure currently in a lot of alfalfa and soybean fields where they’ve just popped in the last two weeks. The bean leaf beetles and armyworms have kind of been the buzz in recent weeks.”