Hooper, Nebraska
October 30, 2008
Dr. Tom Hoegemeyer, Chief
Technology Officer of
Hoegemeyer Hybrids has been closely watching the fall
harvest season in the western cornbelt. Following are his
observations and concerns.
This year has been a VERY unusual year. After many of us were
forced to “mud the crop in”, now we are faced with having to
“mud it out”. And to make matters worse, it was a cooler than
normal spring, summer, and fall. Rather than the crop hitting
“blacklayer” in late August or early September, it really didn’t
get mature until late September, or even October in many areas.
Now we have wet corn in the field.
Before physiological maturity, grain dries down due to a
combination of adding more starch to the kernels, transpiring
water from the green plant, and from evaporation. After
physiological maturity, grain dries primarily from evaporation
from the kernel, with some added transpiration in some hybrids.
Hybrid characteristics such as ear diameter, husk number,
tightness, “staygreen”, and kernel pericarp thickness also
affect the rate of moisture loss. This rate of evaporation, as
you realize, is a function of temperature, humidity, and wind.
To put it simply, warmer, windier, and drier conditions
encourage rapid drydown of corn. Most years, the Western
Cornbelt has her ideal drying conditions, but cool, humid, rainy
weather hampered it this year.
We have several factors working against us concerning rate of
dry down. Most corn matured in late September this year, so even
with “normal” rain and humidity, the lower temperatures after
blacklayer formation would have slowed drying rates a lot.
Second, in most areas we have had over double the “normal”
rainfall combined with periods of cloudy, humid, and cool
weather—just the opposite of what drives drying. Corn drying in
early September will often lose a point or more of moisture per
day. Corn drying in the last half of October will lose less than
a quarter point per day. Add to that the rain, and having to dry
the husk and ear off after each shower before kernel evaporation
has a chance. So we find ourselves with wet corn that likely
won’t dry much unless we have a period of warmer, sunnier and
drier weather.
Stalk quality is also becoming a serious issue. Because corn was
(1) behind in maturity and was filling grain September and early
October, (2) we had cooler, cloudier weather than normal during
grain filling, less photosynthate (sugar) was available to keep
the stalk tissues alive and healthy; the plants were madly
trying to fill the kernels as we had high yield potential set
up. The fungi that cause stalk and root rots are the same ones
that deteriorate residue from the previous crop. They don’t
strongly attack live tissue, but are very effective in breaking
down dead or weakened (poorly nourished) stalks and roots. Plus
the growth rate of these fungi is favored by cool, damp weather.
Thus, we have the perfect storm for stalk and root rot. Add
wind, rain and/or snow, and the potential for problems is large.
My recommendation is that we can’t let a day pass without
hitting harvest hard, because corn isn’t going to get
significantly drier and it will get harder to harvest every day.
If you have questions, send an email to:
askus@therightseed.com,
or directly to Dr. Tom at
drtom@hoegemeyer.com. |
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