August 31, 2012
Recommendations for Storing Drought-stressed Corn
As most rain-fed corn producers are well aware, this year’s hot dry conditions have resulted in lower yields with moderately lower test weights. They have also brought concerns about potential mycotoxin contamination in the grain.
The only way to know if there are mycotoxins in your grain and which specific mycotoxins are present is to have representative samples tested by a certified lab. If the initial screening indicates the presence of mycotoxins, quantitative tests should be run to determine the level of contamination.
Grain Storage Management
Many species of fungi cause mold in grain. Most become associated with the grain in the field, but may continue to grow and reproduce if grain is stored under the wrong moisture and temperature conditions in the bin. If there is a chance molds that produce mycotoxins may have contaminated the bin, dry the grain to 14% moisture. If it will be stored for over a month, dry it down to 13%.
If the corn is found to have any level of mycotoxin contamination, partially fill the bin — one-fourth full is a good place to start — so the fan will produce higher airflow rates (cfm/bu) and dry the grain quicker. If equipped, run a couple rounds with the stirring system, then run a few rounds each time you add 4 or more feet of corn into the bin to equalize the moisture content and prevent over-drying the bottom of the bin. However, don’t overstir as it can cause cracks in the seed coat that can allow fungal organisms to enter the kernels
In addition to getting the corn dry, you need to cool the grain whenever air temperature allows. This will slow the growth rate of the fungal organisms. Run the fans at every opportunity when the air temperature is 10 degrees below the grain temperature in the bin. Continue running fans until the grain is 30° F but there is no need to get it colder than 30° F.
UNL Extension Educator