Identification & Management
Disease control of seedling diseases, charcoal rot, phytophthora root rot, red crown rot, Southern blight, aerial blight, brown leaf spot, downy mildew, frogeye, purple seed stain, anthracnose, pod & stem blight, stem canker, virus or viruslike disease complex, nematodes, root knot and soybean cyst.
Southern stem blight occurs on a wide range of host plants, including soybeans. Soybean losses due to this disease vary considerably, with damage occurring as scattered localized areas of dead plants.
Links to publications and websites related to soybeans and soybean diseases.
This soil borne disease is largely confined to poorly drained clay soils, but may occur on other soils. Severe plant losses and yield reductions are common in susceptible cultivars.
Information other non-parasitic soybean diseases, such as lightning damage and rhizobium induced chlorosis.
Stem canker has caused widespread damage in the southwestern United States in recent years. The disease can be very destructive because it kills plants from flowering to maturity.
Anthracnose occurs in all major soybean growing areas of the world. The disease reduces stands, seed quality and yields.
Pod and stem blight occurs in every soybean producing area of the United States. It is a major cause of seed damage, resulting in poor seed quality.
Peanut mottle is caused by the peanut mottle virus (PMV). It was first observed in 1971 and is the most common virus disease of soybeans in Georgia.
Soybean mosaic is caused by soybean mosaic virus (SMV) and is the most widely distributed virus diseases of soybeans. It is spread by planting diseased seed and by at least 31 species of aphids.
Information about the soybean disease, Bean pod mottle.
Bud blight, caused by the tobacco ringspot virus (TRSV), can be a serious disease of soybeans.
Information about herbicide injury, including dinitroaniline herbicides, triazine herbicides,phenoxoy/benzoic acid herbicides, lightening damage, rhizobium induced chlorosis.
Information about air pollution, including ozone and sulfur dioxide.
Information about the nutrient disorders, potassium deficiency and manganese toxicity.
Information about collecting plant and soil samples for diagnosis.
This is a collection of soybean disease photographs to help diagnose and understand soybean diseases found in Louisiana.
Pythium damping off.
Soybean field affected by Seedling disease.
Fusarium on soybean seedlings.
Stand loss due to Phytophthora.
Southern blight- sclerotia at stem.
Advanced symptoms of soybean Stem canker.
Interveinal chlorosis caused Stem canker.
Southern blight- close up of sclerotia at stem.
Red crown rot foliar symptoms.
Red crown rot on soybean stem base.
Red crown rot root symptoms.
Severe foliar symptoms of Sudden death syndrome.
Sudden death syndrome beginning pod abortion.
Sudden death syndrome pod abortion.
Severe foliar symptoms and defoliation of Sudden death syndrome.
Northern Stem canker in soybean.
Northern Stem canker.
Initial foliar symptoms Sudden death syndrome.
Perithecia on stem base.
Charcoal rot seed symptoms.
Charcoal rot shredded stem.
Charcoal rot root symptoms.
Anthracnose on soybean stems and pods.
Anthracnose on soybean fruiting bodies on stem.
Charcoal rot affected soybean field.
Phytophthora seeding disease.
Phytophthora stem discoloration.
Plant wilting due to Phytophthora.
Phytophthora root rot.
Inner stem discoloration caused by Charcoal rot.
Soybean stem streaks.
Charcoal rot is primarily a root and basal stem disease, but may be seen on above ground parts of infected plants. Diseased tissue in the taproot and lower stem develops a grayish discoloration.
Picture of Stem and pod disease.
Close up of Stem and pod disease.
Photo of Stem and pod disease.
Detail of Stem and pod disease.
Detailed view of Stem and pod disease.
An image of Stem and pod disease.
Pod with Phomopsis on seed.
An example of Stem and pod disease.
Image of Stem and pod disease.
Example of Stem and pod disease.
Inside view of Stem and pod disease.
Pods with cracked coats on left and healthy right with Phomopsis and Pod and stem on center stem.
Internode shortening caused by Tobacco ringspot virus.
Severe stunting Tobacco ringspot.
Bud blight Tobacco ringspot.
Bean pod mottle foliar symptoms.
Bud blight Tobacco ringspot virus.
A photo of Root knot nematode.
Severe Root knot nematode.
Target spot occurs regularly in low incidence in many areas. The disease usually occurs too late in the season to cause economic damage.
Cercospora leaf blight is a late season disease that is often mistaken for early senescence. Symptoms are first observed at the beginning of seed set.
Alternaria leaf spot has been reported from all soybean growing areas. This fungus is often a secondary invader following mechanical injury, insect damage, or another disease.
Chlorosis and stunting caused by Root knot nematode.
Chlorosis due to Root knot nematode.
Root galling from Root knot nematode.
Downy mildew, one of the most common foliar diseases of soybean, occurs worldwide, but is seldom a serious problem.
Powdery mildew occurs sporadically on soybeans. Yield reductions are possible if foliage is affected during pod fill or extensive defoliation occurs.
Aerial blight is found in several states, but is primarily of economic importance in Louisiana where extensive yield losses have been reported.
Brown spot is a common disease which occurs frequently on young plants.
Purple seed stain caused by Cercospora kikuchii.
A picture of Cercospora leaf blight foliar symptoms.
Cercospora leaf blight foliar symptom.
Cercospora leaf blight foliar symptoms and sporulation.
Purple seed stain.
Advanced symptoms of Cercospora leaf blight.
A look at Cercospora blight.
A photo of Cercospora blight.
Photo of Sudden Death Syndrome (SDS).
Powdery mildew on upper leaflet surface.
A look at Sudden Death Syndrome (SDS).
An example of Sudden Death Syndrome (SDS).
Leaf spot caused by Frogeye leaf spot.
A look at Frogeye leaf spot.
An example of Frogeye leaf spot.
Frogeye with halo.