Managing disease can be a frustrating proposition. This Guide can help you identify which disease is damaging your crop.
Take-all Root Rot

© Kansas State University, Department of Plant Pathology
Pathogen(s) causing disease:
Gaeumannomyces graminisvar. triticiSymptoms:
Detectable around jointing time, affected plants are stunted and yellow compared to healthy plants. This early phase of take-all usually goes unnoticed. If take-all is suspected early in the season, plants can be diagnosed in the Plant Diagnostic Laboratory by the presence of take-all fungal mycelium on the roots and crowns.After heading time, take-all symptoms are much easier to detect. Whole plants begin to die and turn color prematurely. The white heads contain little or no grain. Plants may die individually or in large patches. Patches usually occur in wetter areas of the field. Occasionally whole fields are killed and this is how take-all gets its name. Since take-all is a root rot, affected plants pull out of the ground very easily. Diagnosis can be confirmed by the dark black discoloration on the roots and at the base of the stems.
Conditions:
The take-all fungus survives between wheat crops in undecayed crop residue, on grassy weeds, and on volunteer wheat. Since the take-all fungus is short-lived, take-all is primarily a problem in continuous wheat. Take-all builds up slowly, so it's usually the third or fourth year of continuous wheat which is severely damaged.In the fall, the fungus moves from the old residue onto the roots of young wheat seedlings. This requires good moisture and close contact between the old residue andthe new roots. Take-all infestations often originate from weedy grasses in ditches or waterways. Pieces of infected roots and crowns are simply dragged into the field during tillage. Smooth brome, cheat, wheatgrass, and wild barleys are all possible sources. The take-all fungus also produces airborne spores which may play arole in initiating new infections. Take-all is not carried in the seed or by insects.
Management:
Crop rotation is the most important method to control take-all. To avoid take-all or if take-all is present in a field:- Do not plant wheat more than two years in a row.
- Barley, rye, and triticale are less affected by take-all than wheat, but they allow the fungus to survive on their roots. Therefore, rotation with these small grains will not reduce take-all if wheat is planted the next year.
- Oats is an effective small grain rotational crop because it is not affected by take-all.
- A one year rotation with canola between wheat crops controls take-all.
- Plant non-host crops such as peanuts or cotton for at least one year between wheat crops.
- In double-cropping systems, soybeans and grain pearl millet maintain take-all at a high level. Sorghum reduces take-all in a following wheat crop.
- Avoid early planting. Planting earlier than the recommended period lengthens the period for infection in the fall.
- Maintain soil pH at 6.0. pH values above 6.0 due to excessive liming favor take-all. Use soil tests to determine soil conditions.
- Follow fertility recommendations to promote vigorous root growth. Excessive nitrogen and the nitrate form of nitrogen favor take-all. Ammonium forms of nitrogen do not favor take-all.
- Maintain the proper levels of minor elements in the fertility program.
- Avoid excessive tillage to reduce movement of infected plant debris which creates new infection sites. Unlike areas farther north, straw deterioration proceeds rapidly in minimum tillage in the Southest resulting in less fungal tissue to initiate infection.
- Maintain adequate drainage in fields to promote root development.
Sources:
Kansas State UniversityUniversity of Georgia
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.
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By Crop:
Corn
Anthracnose Leaf Blight
Seed Rot
Gray Leaf Spot
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Eyespot
Northern Leaf Spot
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Stewart's Bacterial Disease
Anthracnose Stalk Rot
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Gibberella Stalk Rot
Fusarium Stalk Rot
Diplodia Ear Rot
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Aspergillus Ear Rot
Maize Sward Mosaic
Maize Chlorotic Dwarf
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Seed Rot
Gray Leaf Spot
Common Corn Rust
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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