News

ISU agronomist says crown rot became bigger issue than expected

An extension agronomist says disease pressure was a mixed bag for Iowa farmers throughout the 2026 growing season.

Meaghan Anderson with Iowa State University tells Brownfield, “Southern rust and tar spot were two of the bigger ones that came in really late. Like, so late that I question whether or not they had any effect on the ultimate yield we’re going to harvest from these fields.”

But she says crown rot caught many agronomists and farmers by surprise.

“That was something I didn’t really expect to see so much of,” Anderson said. “I started noticing it fairly early in August and then it just kind of worsened from there.”

According to Iowa State University, crown rot weakens the lower portion of the corn plant, forcing it to pull energy from the stalk during grain fill and increasing the risk of lodging.

Anderson says it’s led to widespread standability issues this fall.

Meaghan Anderson: