As Ken Ferrie traveled through Minnesota and into northern Iowa this past week, he saw a number of fields with rootless corn syndrome, sometimes referred to as floppy corn syndrome.
“These are fields that had been worked, but they’re so dry at the (soil) surface that as we try to make the hand off from the seed (seminal) roots to the crown roots – in that V4 to V5 window – it’s too dry, and the crown roots just come out and nub off,” says Ferrie, Farm Journal Field Agronomist and owner of Crop-Tech Consulting in central Illinois, near Heyworth.
A contributing factor to the problem is when you don’t or can’t firm up the soil tightly enough over the top of the seed when planting in dry conditions.
“That’s why we stay away from a spoked-like closing wheel in a conventional tillage system, because we can’t firm (the soil) enough to keep that moisture tucked in,” Ferrie notes.
The best solution to the problem of rootless or floppy corn is moisture.
“In most cases, all it’s going to take is one good rain shower, and the corn plant will re-anchor,” he says.
In the meantime, some cultivation could potentially help.
“Where we can roll some soil up around the base of the plants, that will stimulate the brace roots to take off,” Ferrie notes.
In fields where corn is leaning heavily, he recommends holding off on herbicide applications, if your specific situation permits a delay.
“I know you’ve got to keep an eye on the weeds and label restrictions, but if you could give this corn a chance to finally set those roots you would be better off,” he says.
If dry conditions persist too long, plants with rootless corn syndrome can have difficulty recovering. “If the plant tips over and the mesocotyl breaks off, that corn won’t survive,” Ferrie says.
Rootworm hatch is underway. In many areas, the hatch is nearly done and larval feeding is becoming evident. Ferrie recommends doing some rootworm floats about the end of June to evaluate the damage.
“It’s to evaluate your traits to make sure that you don’t have rootworms getting around them,” he says.
The floats are also useful for farmers growing non-GMO corn. “It’s helpful if you’re trying to decide whether you can get by without an insecticide,” Ferrie says.
He says if you are unable to do the floats, at the very least take pictures of any significant damage which you can then share with your agronomist. Bear in mind, however, that there is no rescue treatment available for rootworm-damaged corn. The work you do now to evaluate rootworm damage is to help you plan for the 2022 season.
For further insights on pest and disease issues in corn and soybeans at this point in the season, listen to Ferrie’s Boots In The Field podcast below:
