Managing disease can be a frustrating proposition. This Guide can help you identify which disease is damaging your crop.
Eyespot

© Iowa State University
Pathogen(s) causing disease:
Aureobasidium zeaeLocation:
Northern Midwest US states, Ontario, Quebec, Europe and South AmericaSymptoms:
Affected leaves are covered with numerous small round spots. Spots are ~ 1/8 inch in diameter, oval to circular and appear water-soaked. The center of the spot dies, leaving a tan colored center surrounded by a brown/purple border. This border is often circled by a yellow halo. This resembles an eye, hence the name 'eye spot'.Conditions:
Infection favored by prolonged periods of cool, wet weather. Some yield loss if severe infections occur within three to four weeks of silkingManagement:
Plant resistant/partial resistant hybrids. Conventional tillage/moldboard plow (if possible) to bury corn residues. Crop rotation away from continuous corn. Foliar fungicides offer effective control.Sources:
Bloomberg, Jim. Bayer CropScience Corn Disease Identification Guide PowerPoint. 2009.Iowa State University
Crop Disease Guide
To aid your search, we've included a photo and description along with scouting and management options. And we've also added beneficial insects by crop to help in your identification process.
Choose a Disease
By Crop:
Corn
Anthracnose Leaf Blight
Seed Rot
Gray Leaf Spot
Common Corn Rust
Southern Corn Rust
Northern Corn Leaf Blight
Eyespot
Northern Leaf Spot
Southern Corn Leaf Blight
Stewart's Bacterial Disease
Anthracnose Stalk Rot
Diplodia Stalk Rot
Gibberella Stalk Rot
Fusarium Stalk Rot
Diplodia Ear Rot
Gibberella Ear Rot
Fusarium Ear Rot
Aspergillus Ear Rot
Maize Sward Mosaic
Maize Chlorotic Dwarf
Crazy Top
Seed Rot
Gray Leaf Spot
Common Corn Rust
Southern Corn Rust
Northern Corn Leaf Blight
Eyespot
Northern Leaf Spot
Southern Corn Leaf Blight
Stewart's Bacterial Disease
Anthracnose Stalk Rot
Diplodia Stalk Rot
Gibberella Stalk Rot
Fusarium Stalk Rot
Diplodia Ear Rot
Gibberella Ear Rot
Fusarium Ear Rot
Aspergillus Ear Rot
Maize Sward Mosaic
Maize Chlorotic Dwarf
Crazy Top
Wheat
American Wheat Striate Mosaic
Barley Yellow Dwarf Virus
Glume Blotch Complex
High plains mosaic pathogen
Karnal bunt
Leaf rust
Powdery mildew
Scab (fusarium head blight)
Stem rust
Strawbreaker
Stripe rust
Take-all Root Rot
Tan spot
Wheat Spindle Streak Mosaic Virus
Wheat Streak Mosaic Virus
Wheat Soilborne Mosaic Virus
Rhizoctonia Spring Blight
Common Bunt (stinking Smut)
Loose Smut
Barley Yellow Dwarf Virus
Glume Blotch Complex
High plains mosaic pathogen
Karnal bunt
Leaf rust
Powdery mildew
Scab (fusarium head blight)
Stem rust
Strawbreaker
Stripe rust
Take-all Root Rot
Tan spot
Wheat Spindle Streak Mosaic Virus
Wheat Streak Mosaic Virus
Wheat Soilborne Mosaic Virus
Rhizoctonia Spring Blight
Common Bunt (stinking Smut)
Loose Smut
Soybean
Alfalfa mosaic
Anthracnose
Bacterial blight
Bacterial pustule
Bean pod mottle
Brown Stem rot
Cercospora leaf slight
Charcoal rot
Downey mildew
Frogeye leaf spot
Fusarium wilt
Phytophthora root and stem rot
Pod and stem blight
Powdery mildew
Pythium root rot
Rhizoctonia root rot
Septoria brown spot
Soybean mosaic
Soybean rust
Stem canker
Sudden death syndrome
White mold
Anthracnose
Bacterial blight
Bacterial pustule
Bean pod mottle
Brown Stem rot
Cercospora leaf slight
Charcoal rot
Downey mildew
Frogeye leaf spot
Fusarium wilt
Phytophthora root and stem rot
Pod and stem blight
Powdery mildew
Pythium root rot
Rhizoctonia root rot
Septoria brown spot
Soybean mosaic
Soybean rust
Stem canker
Sudden death syndrome
White mold