Incidences of ear rots were particularly high this year, especially in the Blacklands area. Ear rots were caused by a wide variety of fungi, including Aspergillus, Diplodia, Fusarium, Gibberella, Penicillium and Trichoderma. A combination of wet conditions and high insect damage led to corn ears being more prone to ear rots. Along with reduced yields and kernel quality, there is also a concern of mycotoxins in ear rotted corn.
As you wrap up the harvest season, focus on the three S’s to reduce mycotoxins in harvested corn and ear rots in future season:
- Dry and store corn at 13% or less moisture to stop fungi from growing and producing mycotoxins
- If ear rot is significant, store kernels in a cool area (less than 15°F)
- Do not feed moldy kernels, especially pink and green kernels, to personal livestock
- Do not store infected corn longer than a year
- The North Carolina Department of Agriculture will test feed or grain samples for mycotoxins: free for aflatoxins and $75 fee for fumonisins.
- Sanitizing and rinsing equipment to remove soil and spores after use is good practice for managing most diseases.
- Ensure that runoff water does not run into ‘clean’ fields.
- Destroy all stalks and other debris from fields, as soon after harvest as possible. Till debris as deep into the soil as possible, while managing soil erosion.
- Burning is not an effective control method as it only removes the debris on the surface. If burning is used to remove excess debris, it should be combined with tillage to push debris to deeper levels of soil.
- Fungi that cause ear rots may possibly move in windblown rain up to several hundred yards. Neighboring corn fields should also be tilled before corn is planted.
For more details, see the Extension Publication, Corn Ear Rots: Managing Mold and Mycotoxins