I was asked to look at some corn with leaf spots yesterday. The corn is tasseling now and actually silks are coming on the ears. I’ve been seeing these spots on all corn all across the county for some time as I check for disease. The spots I am finding are from herbicide drift and nitrogen burn – mostly herbicide. These are small, yellow spots on leaves from top of the plant down in the canopy some.
I have yet to find disease but Northern Corn Leaf Blight has been seen at low levels by Seminole County Agent Rome Ethredge and Terrell County Agent Nick McGhee. NCLB will have a cigar shaped lesion usually on lower leaves and is generally found in corn with tight rotations – especially corn behind corn. There are other leaf spots I am seeing but are of no concern also.
The photo below resembles Northern Corn Leaf Spot, not blight, and is not an issue or anything to be concerned.