Dusty, Dirty Corn FieldsEarlier this week a corn sample was brought into our office (see photos). The discussion centered on questions about the corn and why there was so much "black, sooty" mold on the leaves, making the fields dusty and dirty. Fritz did a quick search and found a post from University of Nebraska in 2012 that seemed to explain one possibility of what we are seeing.
Here are a few thoughts. Remember the September 13th frost followed by several more frost events that followed? The upper canopy of both beans and corn were killed in many fields. This dead tissue is a great place for these decomposing fungi to start working. These saprophytes live off of the dead tissue, creating the black, sooty mold on the dead leaves - which the corn fields now had plenty of. They are simply "doing their job" decomposing the plant material - recycling. It's just a bit earlier perhaps, because of the frost killed tissue.
Check out this article. Perhaps you are seeing this in your fields too. http://z.umn.edu/q6a
Dirty, Dusty Corn
Lisa Behnken, UM Extension Educator
Fritz Breitenbach, UM IPM Specialist