The growing season and grain fill is all but over for most and has ended on a dry note. All fields I have visited have been tinder dry, as harvest gets underway a reminder to check fire extinguishers and if available, have a tractor hooked to a tillage implement ready to go to help contain a field fire. Checking combines for residue buildup throughout the day and having the local fire department phone number readily available is also recommended. Despite Tar Spot getting a later start in Northeast Illinois, by late August and September it spread throughout the upper corn canopy reflected by image provided. Final yields will share the effect Tar spot and drought had on the 2024 crop. While checking corn fields I am finding very limited olive-green ear rot symptoms. This can be representative of Penicillium ear rot or Aspergillus ear rot. Aspergillus is most favored by hot and dry conditions. Aspergillus ear rot appears most commonly at the tip of the ear but can be scattered throughout. This ear rot is particularly troublesome because of their ability to produce a mycotoxin called aflatoxin. A great resource for identifying and understanding ear rots can be found from the Crop Protection Network. https://cropprotectionnetwork.org/publications/an-overview-of-ear-rots
Wishing a safe harvest to all!