Yellow Leaves Emerge from Twisted Whorls - 2011

June 22, 2011
ICM News

By Roger Elmore, Department of Agronomy

Yellow leaves wave above V5 to V8 corn canopies in northern and central Iowa this week.   These sun-starved leaves freshly emerged from twisted whorls will turn green soon after they begin intercepting sunlight.

Potential causes are numerous:  rapid growth coupled with a wide range of temperatures, hail, strong winds or an application of a herbicide, insecticide or fungicide, etc. 

This reference describes these symptoms and causes in more detail.

Yellow leaves resulting from twisted whorls associated with an application of a growth regulator herbicide. Broadleaf weeds in the photo were affected too.
  Photo by Brian Lang, ISU Extension Field Agronomist; 2011.

I would expect these plants to look almost normal within a few days to a week or so. If the malformation causes a delay in either growth or development, it could result in yield reductions. But any yield reduction would likely be hard to detect on a field basis unless the symptom is widespread.

Roger Elmore is a professor of agronomy with research and extension responsibilities in corn production. He can be contacted by email at or (515) 294-6655.


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