Monitor grain bins closely this spring for moisture and mold
Editor’s note: This article is from the archives of the MSU Crop Advisory Team Alerts. Check the label of any pesticide referenced to ensure your use is included.
Storing
dry corn on farm is riskier than normal this year for many farms in
west central Michigan, especially if it is to be held into the late
spring and summer months. Typically as the weather warms, it is
recommended that aeration fans are run periodically to bring the
temperature of the grain up. Uniform aeration of grain may be quite
difficult in some bins this year.
High grain moisture content during corn harvest made the crop difficult
to thresh and resulted in higher levels of broken kernels and fines in
threshed grain, especially compared to what has been experienced in the
past several years. Because of the increased amount of fines, some grain
handling systems – even those that incorporate equipment such as
screens to help remove the fines – may not have been able to keep up
with the large amounts of fines that were going into the bins with the
grain.
Layers of fines in the bin (or concentrated areas of fines) will
restrict air flow to areas of the grain. As air moves through the grain,
it will always take the path of least resistance going around areas
where fines accumulated. This can lead to the potential for hot spots
and moisture condensation in those areas that are not properly aerated.
In many cases, normal coring of the bins may not have taken enough of
these fines out of the bin. Therefore, extra monitoring of your bins
this spring is essential for minimizing problems in your stored grain.
Also of concern is the potential for uneven moisture in the grain. As
grain was harvested last fall, there was large variation in grain
moisture content in parts of the state, sometimes as wide as 10 points
from mature to immature grain, in many cases from one area of the field
to another. As this grain entered the dryer last fall, the high level of
variation caused the drier to adjust more than usual. There’s concern
whether the sensors in the dryer were sensitive enough to uniformly dry
the corn and whether you were able to effectively aerate the bin to even
out any moisture differences. There is a potential that there are areas
or pockets of higher than intended moisture grain in the bin. With good
air flow through the bin, this would not be a great problem, but
coupled with a large amount of fines, grain may not have dried in the
bin as expected.
Even the most experienced operators should monitor bins with extra care
and caution because of the high number of potential variables with this
stored corn crop. It may be impractical in many large bins to try to
probe them with a grain sampling probe simply because you’re not getting
far enough into the grain. Sampling from the top and bottom access
doors doesn’t give you a sample of what is in the middle of the bin,
around the walls, etc. Also check the exhaust air coming out of the bin
when you first turn on the aeration fans, and while they are running, to
monitor for the smell of mold or sour grain.
To help minimize your potential for loss, if you have any doubts about
the quality of the corn you are storing, you might consider moving a
significant portion of your stored corn to see what you have. If you
find the corn is not flowing out of the bin as expected, or if you have
areas of caking and crusting, or pockets of mold, you should empty those
bins of corn first.