A November “Indian Summer” should not be relied upon to hasten the in-field drying of corn grain so that it can be harvested at moistures of 20% or less.  Even with normal temperatures, one can usually not expect much more than ¼ to ½ percentage point decrease per day.  In the mean time, stalk health and grain quality continue to deteriorate due to the processes of weathering and disease. 

Figure 1 - Gibberella ear rot - Infection in most cases occurs from tip down. Note the dark pink to red colour.

Figure 2 - Fusarium ear mould - Note the white fungal growth and the "starbusrsting" of the kernels.

Figure 3 - Diplodia ear rot- Diplodia in most cases starts from the base of the ear up. Produces a white fungal growth that appears similar to toothpast being smeared on the cob.

In fields where ear rot is a significant problem, corn should be harvested in a timely manner to stop the growth of the ear rot fungi.  If the problem is severe, be sure to check with crop insurance folks regarding adjustments for the damage to the crop.  Usually, these assessments must be made on standing corn prior to harvest. 

In fields where ear rot is a significant problem, corn should be harvested in a timely manner to stop the growth of the ear rot fungi.  If the problem is severe, be sure to check with crop insurance folks regarding adjustments for the damage to the crop.  Usually, these assessments must be made on standing corn prior to harvest. 

Maximize the capacity of the combine to remove fine material and shrunken, mold damaged kernels.  This enhances the efficiency of your aeration system and minimizes additional mold growth.  Additional cleaning during the unloading process may slow down return to the field but should pay big dividends during the drying and storage period. 

Drying capacity should be such that the corn can be quickly dried to below 20%, to arrest the growth of Diplodia and Gibberella after the corn is binned.    For storage into the winter, additional drying down to 15% moisture improves the storability of the grain by controlling storage molds like Penicillium and Aspergillus.  Cool the grain below 50 degrees immediately after drying and eventually cool it to 32 to 35 degrees F.

While grain is in storage, it should be inspected weekly at the minimum, and aerated as needed to keep grain from going out of condition. 

Mold affected grain should be moved before spring if at all possible.  High levels of mold damage may be rejected by ethanol plants since yield is reduced.  If toxins are present, those toxins can be concentrated by a factor of 3 in co-products such as DDGS and WDG. 

Any grain from disease impacted grain destined for livestock feed should be tested for toxins.  Although Diplodia does not produce toxins, Gibberella and other ear rots do.  Young and gestating animals are most susceptible to these corn toxins.