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What to Expect This Fall - All The Charts You Need
What To Expect This Fall
Last week Mark talked
about corn maturing prior to frost this fall. This week we will explore whether
recent cool temperatures may lead to a delayed harvest.
This spring 50 percent
of Ohio corn was in the ground by May 18 compared to 60 percent normally. On
June 1, 88 percent of corn planting was complete and 81 percent emerged by June
8. Most corn was planted in what is considered an average time frame though
some areas were late finishing up. The 31 percent of Ohio corn that was planted
after May 25 is what I will be discussing today.
In Seneca County there
was late planting because of wet spring conditions. Fig. 1 Green line shows a
108 day hybrid planted on May 28. Growing Degree Day (GDD) accumulation was
normal until mid-July where we started turning cooler. The teal colored line
shows 2009 which was a year with cooler temperatures. In this part of Ohio,
corn that was planted late (depending on rated maturity) will be at risk for
delayed harvest and possible freeze before maturity.
Henry County: The 2014
green line is still showing that GDD accumulation is tracking right at normal.
Most Henry County corn was planted earlier than the May 28 date used in Fig. 2.
Use this graph to compare current GDD to 2009.
In the Ohio/
east-central Indiana region we are about 50 GDD behind normal which means it
would take an additional 2.5 normal August days to catch up or an additional
week of October days to catch up. This is of little consequence as far as yield
goes because the moderate temperatures through pollination have actually helped
The two week outlook is
showing temperatures to return to near normal.
My only concern at this
point is for those fields that were planted late. Fields that were planted late
will be at risk of a delayed harvest if we have a cold, wet fall conditions.
Depending on maturity of hybrid planted, they may be at risk for freeze before
they hit black layer. If so, test weight will be reduced, grain will be wetter
at harvest and slower to dry down and yield will be reduced as a result of the
plant shutting down before fully mature.
The 2009 year was an
example of a cool growing season which shut down in late September. However,
2009 produced record corn yields for most areas even though harvest was wet,
the corn was wet, and ear molds were much more common. Current records and
projections do not show 2014 to be as cool as 2009.
You can see that years
with lower temperatures often have the highest corn yields, if there is
It is too early to tell
how severe ear molds will be this year. It is something we are concerned about
because the weather we have had so far has been conducive to ear mold
development (moisture, fog, mild temps). As we move forward into fall the
weather will have an effect on ear molds along with how we manage it at harvest
time. It will be important to monitor the presence of ear molds between now and
harvest. We are at most risk for Gibberela and Diplodia, which like cool wet
conditions at silking time.
Having above average
soil moisture in mid-August is something to say a prayer of thanksgiving for!
Conventional vs. Traited
Corn, by Mark Apelt, CCA
With commodity prices lower than they have been in the past few years, many
farmers will be looking for ways to cut costs. One way farmers may be looking
to trim expenses is reducing traits. Is this a smart option? No one can say
with 100 percent certainty that insects will or will not be an issue next year,
but there are some trends we can look at.
you plant corn after corn the chances for corn rootworm pressure will be
higher. Therefore, choosing CRW (Corn rootworm) traited corn may be a good
option for you. This is often a good option for silage growers who have
more corn/corn rotations.
those growers who use an insecticide late on their soybeans, they may kill
some of the adult corn rootworms who have adapted the strategy of laying
eggs in soybean fields. In this case there may not be as much of an
advantage to using a CRW traited corn in Ohio or eastern Indiana.
corn borers (ECB) overwinter as larvae in corn residue and emerge in the
spring. There are usually two generations of ECB per year, with the
second generation generally being more damaging than the first. The chart
below gives the average percent yield loss from ECB at various growth
stages, depending on the number of borers/plant. Note that the chart does
not include losses from other issues such as stalk lodging and ear drop.
Shot holes on corn plants at the pre-tassel stage
most susceptible corn to ECB will generally be your first and last
planted. The earliest planted corn will attract the first generation
moths, whereas the last planted corn will generally attract the second
generation moths. Corn younger than ~V5 produces a natural compound called
DIMBOA that acts as an antifeedant.
- Use the following formula to determine potential yield loss:
yield loss (Bu./A.) = Anticipated yield (Bu./A.) X level of infestation
(decimal) X yield loss figure (from the table above)
example let’s say you have a potential yield of 200 Bu./A. and 60 percent of
the plants have ECB at the pre-tassel stage. Potential yield loss = 200 x 0.60
x 0.099 which equates to 11.88 bu.
Insecticides can be used to
partially control ECB if an infestation does occur, but they can’t be used to
control CRW. Ultimately the decision to use a conventional corn is up to you.
Hopefully the information provided can help you to make a more informed