Hot and dry cornfield conditions are breeding grounds for dangerous aspergillus ear and kernel mold that produces aflatoxins. This toxin is a known carcinogen, can harm livestock if fed and can lead to rejection at the elevator if abundant in a load.
Drought states are at a particularly high risk for the disease this year.
Aspergillus ear and kernel mold is a green to yellowish green, powdery fungus that survives on plant residue. In addition, spores can be transferred by wind. Damaged and exposed kernels are more susceptible to Aspergillus.
There are ways to manage aflatoxins, according to AgriGold Agronomist Brandon Nystrom.
- Scout to determine if the mold is present
- Change combine settings and grain moving equipment to minimize kernel damage and remove cracks, fines and lightweight, diseased kernels
- Consider harvesting when the corn is above 20% moisture as less Aspergillus will be present and if you do, dry rapidly to at least 14% moisture in under 48 hours
- Don’t store grain in any non-aerated site for more than six hours
- Manage storage conditions to discourage fungi growth, cool dried grain to 35 to 40 degrees Fahrenheit
If you find mold that produces aflatoxins in fields it will limit where you can sell the grain. The table below, from Iowa State University (ISU) Extension showcases outlets for the infected grain.
Note, blending aflatoxin-contaminated corn is not legal except for on-farm use, according to Alison Robertson, professor of plant pathology and microbiology at ISU. Ethanol could be another outlet for infected grain. For on-farm use, anhydrous ammonia can reduce the contamination.