Yellow Leaves Emerge from Twisted Whorls - 2011

June 22, 2011

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: Twisted whorls and 'buggy whipped' corn.


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 relmore@iastate.edu or (515) 294-6655.

Links to this article are strongly encouraged, and this article may be republished without further permission if published as written and if credit is given to the author, Integrated Crop Management News, and Iowa State University Extension and Outreach. If this article is to be used in any other manner, permission from the author is required. This article was originally published on June 22, 2011. The information contained within may not be the most current and accurate depending on when it is accessed.

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