PPDL Picture of the Week
October 5, 2015
Ears on the Same Shank (MESS)
(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.
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".
lengthier discussion about the MESS syndrome is available online at: http://www.kingcorn.org/news/timely/MessyEars.html