What A MESS!
(aka Multiple Ears on Single Ear Shank)
R.L. (Bob) Nielsen
Agronomy Department,
Purdue University
West Lafayette, IN 47907-1150
Internet address: rnielsen@purdue.edu
Author's note: Originally published in August 1998, but relevant to
similar reports being received in August 1999.
The annual Dog Days of August always bring out the odd
stories down at the Chat 'n Chew Café. The latest one originated with
Marty who claimed he was in a corn field the other day checking out the
condition of the developing ears (for which he receives a gold star considering
how hot and muggy it's been lately!). Seems that he was finding multiple-eared
plants along the edges of the field.
Now, multiple-eared plants in
and of themselves are not an oddity. Low plant-to-plant competition (edges of
fields, thin populations, etc.) often results in
successful ear development at more
than one stalk node (joint). This characteristic is often termed
"prolificacy" and some prolific hybrids exist that routinely produce
more than one harvestable ear at respectable plant populations.
However, Marty claims that the
multiple ears were occurring on a
single ear shank, rather than their usual occurrence at individual stalk
nodes (joints). The primary ear was at its usual position at the end of the ear
shank, but one or more additional
ears were developing farther down the same shank.
Well, Marty is not alone in
discovering this phenomenon. At Purdue's SEPAC Field Day on August 18 (if you
missed it, shame on you!), several folks acknowledged that they had seen
similar plants along edges of fields this year. A few of the plants in my own
research plots at SEPAC display this strange multiple-eared appearance.
This multiple-eared oddity,
let's call it the MESS Syndrome (Multiple Ears on a Single Shank), does not
occur very frequently but raises questions when it does show up. Is it a
fertility imbalance? Was it caused by your #@$%! herbicide? Was the seed
genetically-challenged? Will it affect grain yield?
Well, first of all, let's
remember a few things about an ear shank. Basically, an ear shank is a modified
stalk. The husk leaves originate from individual nodes (joints) on the shank,
similar to the plant's regular leaves originating from individual nodes on the
main stalk. Instead of a male flower (tassel) developing at the end of this
modified stalk, a female flower (ear shoot) develops.
Similar to the nodes of the
main stalk, it is physiologically possible for ear shoots to develop at any of the nodes of the ear
shank. Typically, none actually occur. Once in a great while, some do form.
I suspect that the appearance
of the MESS Syndrome simply tells us that the plants had ample energy and
resources during the initiation and development of the ear shoots earlier in
the season, enough that there was extra resources available for the plant to
"invest" in the development of these additional ear shoots. Many of
these "affected" plants also exhibit the more typical second ear
development at the node below the primary ear that is associated with low
plant-to-plant competition. As such, therefore, there is likely nothing
negative about the existence of the MESS Syndrome.
Bottom Line: If you
haven't seen this phenomenon before, take some time this week to walk your
fields and look for it along the edges. You will probably find some. They make
good desk ornaments and also make for good conversation at your next social
event.
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