I'm sure the 1999
growing season had as many days and hours as previous seasons, but
for many of us it sure seemed like a longer than normal year. For
many Mother Nature threw a few curveballs that resulted in some dreadful
corn crops being produced around the state. Fortunately, this kind
of season is a rare occurrence that hopefully may not reoccur for
the remainder of your careers.
I
thought it might be good to revisit a few of the issues we ran into
this summer and review what we learned.
Many
folks were faced with making decisions and doing things that they
had not done before. Cutting silage in early August was one of those
decisions.
One
issue that I was concerned about was the regrowth potential of corn
that was severely drought stressed. Generally it seemed that corn
that had pollinated and had some ears was able to show some recovery
after the rain began in some areas in mid August. Corn that had
no ears did not seem to recover.
Corn
that was chopped for silage often was wetter than it appeared and
their appeared to be a fairly narrow window between too dry and
too wet. Once the rain began to fall and some fields greened up,
then the corn began to take up moisture again and become very wet.
Some reported to me that the density of the silage chopped from
drought stressed fields at the right moisture was lighter than normal.
A key ingredient to success this year was to monitor moistures carefully
and pick and choose fields as they reached the desired moisture
level of 65 to 70%.
I
visited some producers who were continually monitoring moistures
during harvest with reasonably good success. Many who did not ended
up with juicing silage. There is no substitute for testing.
The
forage quality of the drought stunted silage was reasonable, but
not great. Energy levels of this kind of corn were about 80% of
normal. Nitrate levels were generally elevated but within manageable
levels. Potassium levels were elevated across the board, with high
levels in some cases. This is because potassium is taken up early
in the season and then is diluted in the silage during grain fill.
When grain fill is limited, then potassium levels are not diluted.
The fiber digestibility of this silage should be good, because the
plants generally do not produce as much lignin under drought conditions.
By late August I began to see lots of corn borer and earworm damage
to the ears in many Southeast Pa. fields. With this there seemed
to be an increase in the levels of ear molds as well. I had several
samples of ears run through our Diagnostic Clinic and almost all
had evidence of Fusarium and Aspergillus. Fusarium is capable of
producing a variety of mycotoxins and Aspergillus can produce aflatoxin.
The presence of these molds, the low density of the silage this
year and the difficulty of getting the moisture right at harvest
all suggest that we may have more mycotoxin and aflatoxin problems
than normal this year.
There
also is lots of ear smut in many of these drought damaged fields,
and this is typical of drought damaged corn. Generally, smut does
not result in mycotoxins in the silage or grain but it sure is ugly.
I
also anticipated more stalk lodging this year and my trip through
the southeast part of the state last week confirmed this is happening.
It appears to be happening due to a combination of both root and
stalk lodging.
Grain
harvest is underway in some areas and the preliminary reports in
drought stunted areas are that yields are variable, as expected.
In some areas the recovery from the drought has been more than expected
but in other areas there has been essentially no recovery.
I
suspect we may see more harvest losses than usual this year with
the small ears in many locations. Drydown seems to be fairly rapid
in most areas due to the accumulation of heat units that we had,
but I am finding that there is some variability in drought stunted
fields where you'll have some corn that was delayed in maturity
due to the drought and some that has developed well.
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