eports of arrested ear development in corn seem to return every year like the swallows of Capistrano. Arrested ear development goes by several other names: blunt ear syndrome (BES), beer can ears, and hand grenade ears to name a few. When growers discover the problem in their fields, they sometimes use other names that I cannot repeat in this article.
I won’t go into details about the symptoms of BES, other than kernel row number is usually normal for the hybrid, but kernels per row and overall cob length are abruptly truncated (see images below). The abrupt arrest of ear development suggests a single stress event as the causal agent. I wrote a more extensive treatise on the subject last year (Nielsen, 2003) that included some references on possible causes of the problem.
In the past week, I discovered classical BES symptoms in a commercial hybrid and an apparent severe expression of the oddity in a seed production field, both in southern Michigan. I have also received reports of arrested ears in commercial hybrids from Ohio and Pennsylvania. If you come across this oddity yourself, please contact me with any details you can provide about the affected field (see below).
|Classical symptom of "beer can" ear syndrome.||Arrested ears in Pennsylvania (courtesy of Greg Roth, Penn. State Univ.).|
|Classical symptom of "hand grenade" ear symptom.||Closer view of rudimentary tip of ear shoot commonly found on arrested ears.|
|Arrested ear exhibiting "bony" cob structure and rudimentary ear shoot at tip of ear.||Closer view of "bony" cob structure and rudimentary ear shoot at tip of ear.|
|Severely arrested ear of female inbred parent in seed production field.||Closer view of severely arrested ear of female inbred parent.|
|Another example of a severely arrested ear of female inbred parent.||Several severely arrested ears of female inbred parent.|
Nielsen, R.L. (Bob). 2003. Blunt Ear Syndrome in Corn. Corny News Network, Purdue Univ. Available online at http://www.kingcorn.org/news/articles.03/BeerCanEars-0812.html (URL verified 9/6/04).