Information Management to Maximize Your Yields

Anthracnose Leaf Blight, Common Rust, Gray Leaf Spot and Goss’s Wilt Found in Iowa

Adapted from ICM News—Alison Robertson

0805Fig3400Wet, warm weather can lead to high disease pressure in corn plants, and this year has already been a good example of it. Anthracnose leaf blight is common on lower leaves of young corn plants. This disease survives on corn residue so is more common in corn on corn fields. Spores are produced on corn residue and rains splash them onto the lower corn leaves. Dark irregular-shaped lesions appear on the bottom four to five leaves of the corn plant. After canopy closure, it is rare to see Anthracnose leaf blight.

Common rust has been reported in Iowa, but at low incidence. Young plants are being infected this year because of late planting. Goss’s Wilt has been reported in west central Iowa. Goss’s Wilt can be characterized by water soaked leaf margins with freckling on the edges. More Goss’s Wilt may be reported this year if stormy wet conditions continue.

Looking ahead…warm, wet weather favors gray leaf spot and northern leaf blight, both of which reduce yield. Make sure to scout for disease development. Fungicide application after tasselling.