P&PDL Picture of the Week for
May 4, 2009

Corn Leafed Out Underground

Bob Nielsen, Extension Agronomist, Department of Agronomy, Purdue University

Occasionally, corn plants fail to successfully emerge but, instead, leaf out underground. Close inspection of such plants often reveals an unusual "corkscrew" appearance to the mesocotyl or coleoptile. Such twisted growth occurs in response to physical restriction to the elongating mesocotyl/coleoptile (e.g., from soil compaction, crusted surface soils, or cloddy surface soils) or damage to plant tissue that occurs unevenly around the circumference of the mesocotyl (e.g., cold temperature injury, insect feeding). Twisted seedling growth can also occur in response to herbicide injury (e.g., cell growth inhibitors) but, in my experience, occurs less commonly than the other causes. For more information, look at an online
article at http://www.kingcorn.org/news/articles.04/Corkscrew-0501.html.

Click image to enlarge

Purdue Plant & Pest Diagnostic Lab Purdue Cooperative Extension Service