Symptoms of Deer Damage in Corn

Bob Nielsen, Extension Corn Production Specialist, Purdue University

White-tailed deer (Odocoileus virginianus) are one of the few mammals that can cause significant damage to corn in Indiana. The sight of deer grazing in harvested fields for dropped ears of corn is quite common in the fall, but these animals are also attracted to corn fields at about the time kernels reach the milk stage or "roasting ear" stage of development (typically mid-August). The common symptoms resulting from deer feeding on corn at this stage of development are "topless" plants and decapitated ears. The ear symptoms are sometimes mistaken for bird damage, but differ because of the distinct appearance of "cut" husks and missing ends of cobs resulting from the deer chomping" off the ends of the ears. Bird damage (crows, blackbirds, etc) more typically results in shredded ends of husks and barren cob tips.

Fortunately, deer damage to corn is often limited to a few number of rows closest to wooded areas. However, small fields of corn completely surrounded by woodlots or forest areas can sustain significant whole-field damage by deer grazing in mid-August.

Deer damage to plants or ears of corn during the grain filling period often encourages disease infection of the damaged plant tissue by common smut (Ustilago maydis) spores. This disease eventually develops into the ugly or beautiful (eyes of the beholder) mass of fungal tissue on damaged plant parts.

The accompanying images depict deer feeding damage to plants and ears, plus one image showing typical ear damage symptoms resulting from crow feeding. For more information on deer damage to crops and options for control, see the following online publications/sites.

http://www.entm.purdue.edu/entomology/ext/fieldcropsipm/a/wtd.htm

http://www.entm.purdue.edu/wildlife/wild.htm

http://www.agriculture.purdue.edu/fnr/Extension/pdfs/faq16w.PDF