Managing disease can be a frustrating proposition. This Guide can help you identify which disease is damaging your crop.
Septoria brown spot
© Iowa State University
Pathogen(s) causing disease:
Septoria glycinesSymptoms:
Appear first on the cotyledons and unifoliate leaves early in the growing season. Angular, red to brown spots that vary in size from tiny specks to 1/4 inch diameter can be seen on the upper and lower leaf surfaces. Leaves with numerous spots rapidly turn yellow and fall to the ground. Spores produced on leaf spots infect the trifoliate leaves, stems, and pods of the soybean plant. Numerous tan lesions, which eventually become dark brown, appear. Later in the season infected leaves may turn yellow and drop prematurely. Defoliation proceeds from the bottom of the plant toward the top of the plant.Conditions:
High moisture and moderate temperatures (60°–85°F) favor infection and disease development. Spread of the fungus is usually halted during hot, dry weather. Spores are spread by wind and splashing rain. Disease usually stops during hot, dry weather.Management:
Crop rotation allows time for soybean straw with fruiting bodies to degrade. This disease is more severe in continuously cropped soybean fields. For fields with very high levels of brown spot, plow under soybean straw to promote rapid decay.Sources:
U of MOISU
Ohio State
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