PPDL Picture of the Week

October 5, 2015

Multiple Ears on the Same Shank (MESS)

RL (Bob) Nielsen, Extension Agronomist, Purdue University

Most everyone knows that a corn plant initiates a lot of potential ears, one at every stalk node up to the one that becomes the harvestable one. Keen observers of the corn plant also recognize that multiple ears can also be found on the same ear shank. The fact that multiple ears sometimes develop from a single ear shank is not, in and of itself, physiologically unusual. Ear shank development essentially replicates the developmental pattern of the main stalk of the plant. 

*The ear shank is comprised of nodes and internodes just like the main stalk. 

*Each node of an ear shank develops a leaf just like the main stalk, although we add the  adjective  "husk" to describe them. 

*The ear shank terminates with a reproductive organ (the female ear), akin to the main stalk terminating with a reproductive organ (the male tassel). 

*Secondary ear shoots can develop from individual nodes of the ear shank just like secondary ear shoots develop from individual nodes of the main stalk. 


Normally, hormonal apical dominance exhibited by the primary or apical ear on an ear shank (or simple competition for photosynthates) suppresses the initiation or development of secondary ears at lower shank nodes. However, under certain conditions or with certain genetic backgrounds, one or more secondary ear shoots not only initiate successfully, but also continue to develop to the point that their presence is clearly noticeable. While the appearance of one or more additional ear shoots with silks emerging from lower husk leaves may not be attractive, I do not believe there is any real detriment to the plant by their existence as long as the primary ear is "normal". 


A lengthier discussion about the MESS syndrome is available online at: http://www.kingcorn.org/news/timely/MessyEars.html 

​Click image to enlarge


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