Crop & Pest Report

Accessibility


| Share

Yellow Plants and Twisted Whorls in Corn (06/30/16)

There have been reports from many regions of the state of random corn plants that have newly emerged leaves that are bright yellow (see accompanying photos).

Yellow Plants and Twisted Whorls in Corn

There have been reports from many regions of the state of random corn plants that have newly emerged leaves that are bright yellow (see accompanying photos). After more careful investigation of a field in Cass County, we found that these yellow plants were associated with twisted or buggy whipped whorls. This phenomenon is not that uncommon and has been referred to as the twisted whorl syndrome. As leaves in the twisted whorls unfurl, they are yellow in color until they are fully exposed to sunlight. These yellow plants will green up in a couple of days after the twisted leaves are unfurled.              

When we see twisted whorls we normally think that they are caused by a misapplication of a growth regulator type herbicide. This can certainly cause this symptom. However, in most of the cases that have been reported to me, no such herbicides had been applied. The other reported cause of this syndrome is a physiological response induced by significant changes in temperature during certain vegetative growth stages. A warm period followed by a cool period (length not defined) or a cool period followed by a warm period (a rapid growth spurt followed by slow development) seem to disrupt the way that leaves develop causing leaf deformations that eventually result in twisted whorls. Why some plants are impacted and others nearby are not, is a bit of a mystery. In almost all cases the tightly twisted leaves unfurl and the plants resume normal development. Others writing about this syndrome indicate that it does not cause a yield loss. For additional information on this topic see the article by Bob Nielsen from Purdue.

plsc.ransom.1 3

Joel Ransom

Extension Agronomist for Cereal Crops

Creative Commons License
Feel free to use and share this content, but please do so under the conditions of our Creative Commons license and our Rules for Use. Thanks.