The unprecedented spring we witnessed not only kept many growers from planting a corn crop, but also made it difficult for the corn acres that were planted to reach their full potential. One issue to keep an eye out for is “Rootless Corn Syndrome” or “Floppy Corn Syndrome”.

Floppy Corn Syndrome is characterized as corn that has some decent height, looks dark green and healthy until a wind comes through and “flops” the corn over and the plant lays on its side. This has often been falsely blamed on herbicide damage or fertilizer burn, but, in most situations, is caused by planting at too shallow of depth.

The first set of roots that develop after planting are known a seminal roots and their primary job is to support the young seedling until it is emerged. Then, at about V1, the plant begins to develop nodal roots which provide primary support and begin to collect the nutrients in the soil. The nodal root develops at the lowest node on the corn plant, which is about ¾ of an inch above the seed. When seed is planted less than an inch below the soil surface, the lowest node can be at or slightly below the soil surface where the soil is typically hotter and dry enough to desiccate the nodal roots causing them to die and not develop. We faced many conditions from the high precipitation that could have caused the planters not to place the seed at a proper depth. Some of which include:

1. Over-worked soils that were loose and fluffy when planted, then a heavy rain compressed the soil putting the seed depth more shallow than desired.
2. Planting through wet spots can cause mud to build up on the depth gauge wheel to the point where it keeps the seed from going into the set depth.
3. Heavy rains caused the soil to become tighter and the planter did not have enough down force to get deep enough into the soil.
4. Open seed slots resulting from planting through a wet soil and the nodal roots were unable to penetrate the seed wall before dying.

If Floppy Corn Syndrome develops, corn plants will continue to put out nodal roots.  After it falls over, and if there is adequate moisture, the plant will put out nodal roots and curve and grow upright. So, all hope is not lost if it flops. However, harvest may be slowed.

Resources and Additional Information

https://www.agry.purdue.edu/ext/corn/news/timeless/floppycorn.html

https://crops.extension.iastate.edu/rootless-corn-syndrome

https://www.agry.purdue.edu/ext/corn/news/timeless/roots.html

Download a copy of this technical bulletin here: Floppy Corn Syndrome