DROOPY EARS IN CORN
R.L. (Bob) Nielsen
Agronomy Dept.
Purdue Univ.
Ears of com normally re
main erect until sometime
after physiological maturity
has occurred (black layer de
velopment), after which the
ear shanks eventually collapse
and the ears decline or
“droop” down. This year, com
field connoisseurs have report
ed droopy ears in fields before
they reached physiological
maturity.
Droopy ears are cute on
certain breeds of dogs, but
Excellent quality seed that exceeds:
• 95% warm germ
• 85% cold germ
• 97% pure
• We treat our seed with the most effective seed treatments in
the industry.
• We continually review the newest developments in seed
treatment and make changes as improved treatments become available.
• We sell only well-graded seed. Even in plateless planters there
is a yield reduction when you use un-graded or plateless seed.
The best, most appropriate genetics for your farm.
Professional, knowledgeable, and well-informed representatives to
help you understand your choices.
Excellent replant policy
2.
3.
• Quick Service
• Agronomic consultation
• Reasonably priced replant seed
Courteous seed delivery, on time, protected from weather.
Honest and fair treatment with the customer’s best interest our priority.
The right to return any undamaged seed prior to May 31 for full credit.
Bird Hybrids/Keystone Group
Family owned, located in Pennsylvania “We raise and use what we sell!”
TALK NEWS
UPDATE
lIA CORN GROWERS ASSOC., INC.
droopy ears on com plants
prior to physiological maturity
are a signal that grain fill has
slowed or halted. Premature
ear declination (the fancy
term for this problem) results
in premature black layer for
mation, lightweight grain, and
ultimately lower grain yields
per acre.
What Causes Droopy Ears?
The few times over the
years that I have observed this
symptom, severe drought
stress has been a common de
nominator. Similar instances
of premature ear declination
occurred in areas of drought
HYBIRDS
'STOMER BILL OF Rl
RR 1 BOX 81A
New Columbia, PA 17856
1-888-825-5088
(Local: 570-538-1170)
teystone Grou
Committed to Excellence
in the Field!
stress in 1991 and 1995.
Under severe drought condi
tions, but where a sizable ear
nonetheless exists, a reduction
in the turgidity of the ear
shank occurs and the weight
of the developing causes the
ear shank to collapse.
In some instances, collapsed
ear shanks can also result
from extensive tunneling by
European com borer larvae.
Such tunneling weakens the
ear shank, allowing it to col
lapse, and can ultimately also
cause ear droppage from the
plant.
Impact on Yield?
Remember that the ear
shank is the final “pipeline”
for the flow of photosynthates
into the developing ear. An
ear shank that collapses prior
to physiological maturity will
greatly restrict, if not totally
prevent, the completion of
grain fill for that ear, and will
likely cause premature black
layer development in the
grain. If the droopy ears
you’ve looked at have not
black layered yet, they will
soon.
Lancaster Farming, Saturday, October 19, 2002, Corn Talk-Ell
(DdDIH IPMJK MIWO
The timing of the onset of
droopy ears determines the
magnitude of the expected
yield loss. If grain fill were to
tally shut down at the full
dent stage of grain develop
ment (milk line barely visible
at dent of kernels), the yield
loss would be as much as 40
percent. If grain fill were to
tally shut down at the late
dent stage of grain develop
ment (milk line halfway be
tween dent and tip), yield
losses for the affected ears
would equal about 12 percent.
Multiplying the percentage
of affected ears in a field by
the estimated yield loss per
ear will give you an estimate
of whole field loss. For exam
ple, if 10 percent of the field
contained plants whose ears
drooped prematurely at the
late dent stage, whole field
loss would be estimated at 1.2
percent (10 percent of the ears
multiplied by 12 percent yield
loss per ear).
Don’t forget this and other
timely information about com
can be viewed at the Chat ’n
Chew Cafe on the World
Wide Web at http://
www.kingcorn.org/cafe. For
other information about corn,
take a look at the Com Grow
ers’ Guidebook on the World
Wide Web at http://
www.kingcom.org/.