Tips to identify, manage crazy top in corn

JASONVILLE, Ind. — Ever notice an unusual cluster of leaves where tassels should be in the cornfield? The aptly named “crazy top” could be the culprit.

Crazy top is an uncommon corn disease caused by downy mildew fungus. It occurs when young plants are subjected to 24 to 48 hours of soil saturation between planting and V5.

The disease also brings about a deformation of plant tissues including excessive tillering and rolling of leaves. Leaves of infected plants may be narrow and strap-like in shape, leathery in texture and yellow or yellow striped in color.

The good news is, crazy top isn’t a huge concern.

“It’s almost more of a novelty when you see it,” said Pioneer Field Agronomist Ben Jacob. “Take note of it. Show it to your neighbors. It’s not going to cause a significant yield impact overall.

“As far as management of crazy top corn goes, the number of things we can do is limited. We can look at improving drainage in that field, whether by adding tile or surface drainage. We can also look to control grass weed species, as they are alternative hosts for crazy top.”