Foliar

Aerial web blight

Name	Aerial web blight
Importance	medium
Alternative name	Aerial blight, Rhizoctonia aerial blight
Pathogen	Rhizoctonia solani
Geographical range	Southern US
Stage start	R1
Stage end	R6
Descriptions	Commonly infects soybeans in rotation with rice (sheath blight in rice). High temperatures, heavy dew, and high humidity/rainfall favor Aerial web blight development. More likely in fields with narrow row spacing. Sclerotia and mycelia survive in soil and crop residue.
Symptoms	A web of mycelium forms on leaves when they are wet. Leaves stick together, wilt, and become tattered. Dark brown sclerotia 1-5 mm long may be present plant tissue. Leaves with reddish-brown margins, erly leaf drop, or pod abortion. Wilted leaves and delayed maturity.
Where	Lower to middle canopy, working upward
Citation	Mueller, D., Wise, K., Sisson, A., Smith, D., Sikora, E., Bradley, C., and Roberston, A. 2016. A Farmer’s Guide to Soybean Diseases. The American Phytopathological Society.

Bacterial blight

Name	Bacterial blight
Importance	medium
Pathogen	Pseudomonas syringae sub. glycines
Geographical range	Midwest/Eastern US
Stage start	V1
Stage end	R6
Descriptions	Common during wet weather or in irrigated fields.
Symptoms	Dark spots often with yellow halo. Lesions coalesce.
Where	Upper canopy
Citation	Mueller, D., Wise, K., Sisson, A., Smith, D., Sikora, E., Bradley, C., and Roberston, A. 2016. A Farmer’s Guide to Soybean Diseases. The American Phytopathological Society.

Bacterial pustule

Name	Bacterial pustule
Importance	low
Pathogen	Xanthomonas axonopodis pv. glycines
Geographical range	Midwest/Eastern US
Stage start	v5
Stage end	R6
Descriptions	Development is favored in wet/rainy or humid conditions and warm or hot temperatures. Sporadic and unlikely to cause yield loss. Could be confused with bacterial blight, Spetoria brown spot, or soybean rust. Overwinters in crop residue and on seed. Transmitted by seed, wind, rain, or machinery.
Symptoms	Foliar lesions begin as small light green spots with yellow halos. Lesions turn brown at the center and raised pustules appear on the leaf surface.
Where	Upper canopy
Citation	https://www.ag.ndsu.edu/publications/crops/soybean-disease-diagnostic-series#section-17 https://soybeanresearchinfo.com/soybean-disease/bacterial-pustule/

Cercospora leaf blight

Name	Cercospora leaf blight
Abbr	CLB
Importance	medium
Pathogen	Cercospora kikuchii
Geographical range	Midwest/Eastern US
Stage start	VC
Stage end	R8
Descriptions	Warm, humid weather.
Symptoms	Bronzing of leaves in upper canopy.
Where	Upper canopy, leaves exposed to sunlight
Citation	Mueller, D., Wise, K., Sisson, A., Smith, D., Sikora, E., Bradley, C., and Roberston, A. 2016. A Farmer’s Guide to Soybean Diseases. The American Phytopathological Society.

Downy mildew

Name	Downy mildew
Importance	medium
Pathogen	Peronospora manshurica
Geographical range	Midwest/Eastern US
Stage start	V5
Stage end	R6
Descriptions	Weather dependent disease. Favored by cool, wet weather. Younger leaves are more susceptible.
Symptoms	Small, irregularly shaped lesions on the upper surfaces of leaves. Pale-green to light-yellow spots turn to yellow spots. Fuzzy gray tufts on the underside of infected leaves.
Where	Young leaves
Citation	Mueller, D., Wise, K., Sisson, A., Smith, D., Sikora, E., Bradley, C., and Roberston, A. 2016. A Farmer’s Guide to Soybean Diseases. The American Phytopathological Society.

Frogeye leafspot

Name	Frogeye leafspot
Abbr	FELS
Importance	high
Pathogen	Pseudomonas syringae sub. glycines
Geographical range	Midwest/Eastern US
Stage start	R2
Stage end	R6
Descriptions	Warm, humid weather. New leaves are susceptible.
Symptoms	Round, tan lesions with a reddish-purple border.
Where	Mid to upper canopy
Citation	Mueller, D., Wise, K., Sisson, A., Smith, D., Sikora, E., Bradley, C., and Roberston, A. 2016. A Farmer’s Guide to Soybean Diseases. The American Phytopathological Society.

Phyllosticta leaf spot

Name	Phyllosticta leaf spot
Importance	low
Pathogen	Phyllosticta sojicola
Geographical range	Midwest/Eastern US
Stage start	V5
Stage end	R6
Descriptions	More common in cool temperatures, wet conditions, or short crop rotations. Transmitted through infected seed. Does not typically impact yield. Could beconfused with frogeye leafspot or Septoria brown spot.
Symptoms	Leaf lesions begin as light green spots. Lesions become gray to tan with narrow dark purple to brown margin. Lesion shape is oval, circular, or irregular/V-shaped. Small black pycnidia (fungal specks) may be present in lesion center. Lesions may be present on petioles, stems, and pods. Necrotic holes in tissue may form at the center of lesions.
Where	Upper leaf surface
Citation	https://cropprotectionnetwork.org/encyclopedia/phyllosticta-leaf-spot-of-soybean https://www.ag.ndsu.edu/publications/crops/soybean-disease-diagnostic-series#section-22

Powdery mildew

Name	Powdery mildew
Abbr	PM
Importance	low
Pathogen	Erysiphe diffusa
Geographical range	Midwest/Eastern US
Stage start	R3
Stage end	R7
Descriptions	When development occurs early in the season, yield losses may occur. Develops in cool conditions, <75°F (24°C), and low humidity levels. Most severe in late-planted soybeans.
Symptoms	White, powdery fungal mycelial growth on leaves and all aboveground parts. White fungal growth in small, irregular areas, until growing together. Tiny black chasmothecia may be present on the underside of leaves. Yellowing and vein necrosis may also develop. Seeds may be shriveled or not fully developed.
Where	Upper leaf surfaces, petioles, and stems
Citation	Mueller, D., Wise, K., Sisson, A., Smith, D., Sikora, E., Bradley, C., and Roberston, A. 2016. A Farmer’s Guide to Soybean Diseases. The American Phytopathological Society.

Septoria brown spot

Name	Septoria brown spot
Importance	high
Alternative name	Brown spot, Septoria leaf spot
Pathogen	Septoria glycines
Geographical range	Eastern US
Stage start	V1
Stage end	R6
Descriptions	Survives on residues.
Symptoms	Brown spots on lower leaves. Followed by yellowing and leaf drop.
Where	Lower leaves
Citation	Mueller, D., Wise, K., Sisson, A., Smith, D., Sikora, E., Bradley, C., and Roberston, A. 2016. A Farmer’s Guide to Soybean Diseases. The American Phytopathological Society.

Soybean rust

Name	Soybean rust
Importance	low (in US)
Pathogen	Phakopsora pachyrhizi; P. meibomiae
Geographical range	Southern US
Stage start	R1
Stage end	R7
Descriptions	Pustules may produce spores for several weeks. Cool, wet weather and high relative humidity are favorable conditions. Early season infection casues premature defoliation, reduced pod and seed number.
Symptoms	Small grayish lesions to begin. Later tan or reddish-brown spot approximately 5 mm in diameter. Mature lesions contain small pustules, usually on the lower leaf surface.
Where	Initially in the lower canopy after canopy closure
Citation	Mueller, D., Wise, K., Sisson, A., Smith, D., Sikora, E., Bradley, C., and Roberston, A. 2016. A Farmer’s Guide to Soybean Diseases. The American Phytopathological Society.

Target spot

Name	Target spot
Importance	low
Pathogen	Corynespora cassiicola
Geographical range	Southern US
Stage start	V1, R3
Stage end	V2, R6
Descriptions	Wet conditions and cool soil temperatures are favorable. The fungus survives on plant residue and has a wide host range.
Symptoms	Forms reddish-brown lesions on leaves, often with yellow halos. Tiny spots/esions occur on stems and petioles. Small, sunken and dark lesions occur on pods.
Where	Infects nearly all plant parts
Citation	Mueller, D., Wise, K., Sisson, A., Smith, D., Sikora, E., Bradley, C., and Roberston, A. 2016. A Farmer’s Guide to Soybean Diseases. The American Phytopathological Society.

Wildfire

Name	Wildfire
Importance	low
Pathogen	Pseudomonas syringae pv. tabaci
Geographical range	Southern US
Stage start	V5
Stage end	R6
Descriptions	Favored in wet and warm conditions. Survives on crop residue, seed, and alternative hosts. Inoculum can be spread by splashing water and rain.
Symptoms	Foliar lesions that are light-dark brown up to 1/2 inch (12 mm) in diameter. Wide yellow halos which streak across the leaf tissue. Dead spots in the lesions fall away and begin to look tattered or even cause defoliation.
Where	Leaves
Citation	https://www.plantdiseases.org/wildfire-soybean-0

Root_Stem

Anthracnose stem blight

Name	Anthracnose stem blight
Abbr	ASB
Importance	medium
Pathogen	Colletotrichum truncatum
Geographical range	Midwest/Eastern US
Stage start	R2
Stage end	R7
Descriptions	ASB causes damage when present early in the season. Warm, wet weather favors infection and development of ASB during bloom and pod development. The fungus survives the winter in crop residue and on infected seed.
Symptoms	Irregularly shaped red-dark brown blotches on stems and petioles in early reproductive stages. Petiole infection may results in a shepherd’s crook and premature defoliation. Foliar symptoms are reddish veins, leaf rolling, and premature defoliation. Pods may become empty. Signs include small black fungal bodies visible on stems, petioles, and pods. Seeds ay be infected and show gray or brown spots with black specks.
Where	stem and foliar during R5-R7
Citation	Mueller, D., Wise, K., Sisson, A., Smith, D., Sikora, E., Bradley, C., and Roberston, A. 2016. A Farmer’s Guide to Soybean Diseases. The American Phytopathological Society.

Brown stem rot

Name	Brown stem rot
Importance	high
Pathogen	Cadophora gregata, Phialophora gregata
Geographical range	North Central US
Stage start	R1
Stage end	R6
Descriptions	Infection of the roots. Easily confused with sudden death syndrome.
Symptoms	Yellowing and browning between leaf veins. Browning of the inner pith tissue.
Where	Browning of the inner pith tissue of the lower stem
Citation	Mueller, D., Wise, K., Sisson, A., Smith, D., Sikora, E., Bradley, C., and Roberston, A. 2016. A Farmer’s Guide to Soybean Diseases. The American Phytopathological Society.

Charcoal rot

Name	Charcoal rot
Importance	high
Pathogen	Macrophomina phaseolina
Geographical range	Midwest/Eastern US
Stage start	R3
Stage end	R8
Descriptions	Disease more common in dry years or dry regions . Starts as premature yellowing followed by wilting and plant death . Survives in the soil as microsclerotia.
Symptoms	Small, hard, black microsclerotia in root and stem tissue. Patches of wilted plants.
Where	Buildup of black microsclerotia visible near season end on and in stem
Citation	Mueller, D., Wise, K., Sisson, A., Smith, D., Sikora, E., Bradley, C., and Roberston, A. 2016. A Farmer’s Guide to Soybean Diseases. The American Phytopathological Society.

Fusarium root rot and wilt

Name	Fusarium root rot and wilt
Importance	high
Pathogen	Fusarium spp.
Geographical range	Midwest/Eastern US
Stage start	VE
Stage end	R5
Descriptions	Causes pre- and postermegence damping off. Young plants are at the greatest risk of root rot.
Symptoms	Discolored reddish-brown to dark-brown roots. Poorly developed roots with poor nodulation. Stunted and week seedlings. Plant wilting.
Where	Seedlings
Citation	Mueller, D., Wise, K., Sisson, A., Smith, D., Sikora, E., Bradley, C., and Roberston, A. 2016. A Farmer’s Guide to Soybean Diseases. The American Phytopathological Society.

Phytophthora root rot and stem rot

Name	Phytophthora root rot and stem rot
Importance	high
Pathogen	Phytophthora sojae
Geographical range	Midwest/Northeastern US
Stage start	VE
Stage end	R5
Descriptions	Occurs most commonly in poorly drained soils. Older infections may be confused with other stem diseases.
Symptoms	Early season seed rot and pre- and postemergence dampling-off. Water-soaked stems. Leaves chlorotic and plants my wilt/die. Dark brown lesion on the lower stem that extends up from the taproot.
Where	Seedlings and stems of older plants
Citation	Mueller, D., Wise, K., Sisson, A., Smith, D., Sikora, E., Bradley, C., and Roberston, A. 2016. A Farmer’s Guide to Soybean Diseases. The American Phytopathological Society.

Pythium seedling blight and root rot

Name	Pythium seedling blight and root rot
Importance	low
Pathogen	Pythium aphanidermatum
Geographical range	Midwest/Eastern US
Stage start	VE
Stage end	V4
Descriptions	Impacts single plants or patches within fields.
Symptoms	Pre- or postemergence damping-off. Infected seedlings have water-soaked lesions. Soft, brownish-colored rotting tissue. Rotted roots cause older plants to become yellow or wilted.
Where	Seedlings and roots of older plants
Citation	Mueller, D., Wise, K., Sisson, A., Smith, D., Sikora, E., Bradley, C., and Roberston, A. 2016. A Farmer’s Guide to Soybean Diseases. The American Phytopathological Society.

Red crown rot

Name	Red crown rot
Importance	low
Pathogen	Calonectria ilicola
Geographical range	Southern US
Stage start	R3
Stage end	R7
Descriptions	May occur in patches or single plants. Survives as microsclerotia in the soil or crop residue over winter and invades roots in the spring.
Symptoms	Red, sunken lesions occur on the plant immediately above the soil line. Red-orange spots (perithecia) present on the lower stem near the soil line. Foliar symptoms only observed later in the reproductive stages. Upper leaves show yellow spots between veins. Later leaves display large, chlorotic areas between veins, with green veins. Petioles eventually drop off the plant.
Where	Stem at the soil line
Citation	Mueller, D., Wise, K., Sisson, A., Smith, D., Sikora, E., Bradley, C., and Roberston, A. 2016. A Farmer’s Guide to Soybean Diseases. The American Phytopathological Society.

Rhizoctonia seedling blight and root rot

Name	Rhizoctonia seedling blight and root rot
Importance	low
Alternative name	Rhizoctonia root rot
Pathogen	Rhizoctonia solani
Geographical range	Midwest/Eastern US
Stage start	VE
Stage end	V5
Descriptions	Warm and moist soil while plants are in early vegetative stages. Delayed planting in spring due to rain. High soil organic matter. Plant stress due to physical or chemical/herbicide injury. Causes most damage during early vegetative growth stages.
Symptoms	Rusty-brown, dry, sunken lesions on lower parts of stems. Dark brown lesions than girdle the stems near the soil. Plants stunted, yellow, and wilting.
Where	Crown, stem of seedlings
Citation	https://www.ag.ndsu.edu/publications/crops/soybean-disease-diagnostic-series#section-4

Root-knot nematode

Name	Root-knot nematode
Abbr	RKN
Importance	low
Pathogen	Meloidogyne spp.
Geographical range	Southeast US
Stage start	V5
Stage end	R6
Descriptions	Several species of nematode present in Southern U.S, with M. aremaria present in peanut/soy rotation. Northern RKN not known to cause economic damage in soybean. Commonly found in sandy soils and in drought conidtions. Common weed/crop species (dandelion, purslane, cotton, and peanut) are also hosts. Cultivation and movement of soil can spread nematodes. Infected plants are more susceptible to other diseases, like Fusarium wilt.
Symptoms	Symptoms appear in patches. Plants appear to have reduced vigor and are wilting, yellowing and stutned/plant death. Canopies are often not completely closed. Underground symptoms include large galls on the roots.
Where	Roots, canopy
Citation	Mueller, D., Wise, K., Sisson, A., Smith, D., Sikora, E., Bradley, C., and Roberston, A. 2016. A Farmer’s Guide to Soybean Diseases. The American Phytopathological Society.

Southern blight

Name	Southern blight
Importance	low
Alternative name	Sclerotium blight
Pathogen	Sclerotium rolfsii
Geographical range	Southeast US
Stage start	R1
Stage end	R6
Descriptions	Hot temperatures are favorable (>80°F, 27°C) and drought conditions with sandy soils, high organic matter. Can infect high numbers of plants within one field. Survives as sclerotia, tan-red-brown structures, over winter.
Symptoms	Wilting and plant death. Stem near the soil surface reveals dark lesion and white fungal growth.
Where	Lower stem
Citation	Mueller, D., Wise, K., Sisson, A., Smith, D., Sikora, E., Bradley, C., and Roberston, A. 2016. A Farmer’s Guide to Soybean Diseases. The American Phytopathological Society.

Soybean Cyst Nematode

Name	Soybean Cyst Nematode
Abbr	SCN
Importance	high
Pathogen	Heterodera glycines
Geographical range	Midwest/Eastern US
Stage start	V5
Stage end	R6
Descriptions	Patches in the field . The SCN can survive in the soil in protective cyst for many years. High pH soils, dry and sandy conditions may favor SCN.
Symptoms	Aboveground symptoms may not appear for years. Stunting, chlorosis, and delayed canopy closure. Tiny, lemon-shaped, white females attached to roots 1.5 months after soybean planting.
Where	Look for white to yellow females on roots, but often no visible aboveground symptoms
Citation	Mueller, D., Wise, K., Sisson, A., Smith, D., Sikora, E., Bradley, C., and Roberston, A. 2016. A Farmer’s Guide to Soybean Diseases. The American Phytopathological Society.

Stem canker

Name	Stem canker
Importance	medium
Pathogen	Diaporthe phaseolorum var. caulivora; Diaporthe aspalathi
Geographical range	Midwest/Eastern US
Stage start	R2
Stage end	R7
Descriptions	Occurs in patches within fields or affects entire fields. Extended wet eather early in the season is favorable for development. Fungi survive in residue and soil for years and spores are splashed onto plants.
Symptoms	Initially small, reddish-brown lesions on lower part of the stem Lesions expand longitudinally and form cankers that girdle the stem. Interveinal chlorosis and necrosis, plant death.
Where	Lower stem
Citation	Mueller, D., Wise, K., Sisson, A., Smith, D., Sikora, E., Bradley, C., and Roberston, A. 2016. A Farmer’s Guide to Soybean Diseases. The American Phytopathological Society.

Sudden death syndrome

Name	Sudden death syndrome
Abbr	SDS
Importance	high
Pathogen	Fusarium virguliforme
Geographical range	Midwest/Eastern US
Stage start	V1, R2
Stage end	V2, R6
Descriptions	Infection of the roots. Seedlings susceptible . Fungal structures on taproot.
Symptoms	Yellowing and browning between leaf veins . Discoloration of vascular tissue. Light gray to brown taproot.
Where	Low or compacted ares look for mottled leaves and infected taproot
Citation	Mueller, D., Wise, K., Sisson, A., Smith, D., Sikora, E., Bradley, C., and Roberston, A. 2016. A Farmer’s Guide to Soybean Diseases. The American Phytopathological Society.

Taproot Decline

Name	Taproot Decline
Importance	low
Pathogen	Xylaria arbuscula
Geographical range	Southern US
Stage start	V6
Stage end	R6
Descriptions	Overwinters on plant residue. New within the last 15 years.
Symptoms	Interveinal chlorosis and necrosis. Blackened tap and lateral roots. Some seedlings and smaller vegetative plants may die-off. White myeclial growth in pith near the crown may be present along with vascular staining.
Where	Leaves in lower canopy early and entire canopy by R5
Citation	Mueller, D., Wise, K., Sisson, A., Smith, D., Sikora, E., Bradley, C., and Roberston, A. 2016. A Farmer’s Guide to Soybean Diseases. The American Phytopathological Society.

Thielaviopsis root rot

Name	Thielaviopsis root rot
Importance	low
Alternative name	Black root rot
Pathogen	Thielaviopsis basicola
Geographical range	Midwest US
Stage start	VE
Stage end	V2
Descriptions	Occurs on soybeans after the reproductive growth stages begin until harvest. Typically does not cause much yield loss.
Symptoms	Irregualry shape, red to dark-brown spots on the stems and petioles. Infection of the petioles may cause a shepherd’s crook or premature defoliation. Leaves show red discoloration of veins, leaf rolling, and premature defoliation. Young pods can have smaller or no seeds. Additional signs include small balck spines and spores on stems, petioles, and pods. Seeds may show brown discoloration and have gray-black specks.
Citation	Mueller, D., Wise, K., Sisson, A., Smith, D., Sikora, E., Bradley, C., and Roberston, A. 2016. A Farmer’s Guide to Soybean Diseases. The American Phytopathological Society.

White mold (Sclerotinia stem rot)

Name	White mold (Sclerotinia stem rot)
Abbr	WM
Importance	high
Alternative name	Sclerotinia stem rot
Pathogen	Sclerotinia sclerotiorum
Geographical range	North Central US
Stage start	R5
Stage end	R7
Descriptions	Cool, wet weather. Check for apothecia on sclerotia at the soil surface. Common in fields with dense canopies and narrow rows. Sclerotia remain in the soil for multiple years.
Symptoms	Wilted, dying plants in patches in the field. White, fuzzy mycelial growth on the stem. Black sclerotia on/in the stem and pods.
Where	Stem and pods
Citation	Mueller, D., Wise, K., Sisson, A., Smith, D., Sikora, E., Bradley, C., and Roberston, A. 2016. A Farmer’s Guide to Soybean Diseases. The American Phytopathological Society.

Seed_and_Pod

Phomopsis seed decay

Name	Phomopsis seed decay
Importance	medium
Pathogen	Diaporthe longicolla
Geographical range	Midwest/Eastern US
Stage start	R6
Stage end	R8
Descriptions	Associated with stem decays. Colonization of seed. Especially present during delayed harvest.
Symptoms	Infected seeds are cracked, shrivelled, and have a chalky, white appearance. If infected seeds are planted, seedlings may have red-brown lesions on stems. Thin black lines may be present on lower internal portions of seedling stems.
Where	On seed and in pods
Citation	Mueller, D., Wise, K., Sisson, A., Smith, D., Sikora, E., Bradley, C., and Roberston, A. 2016. A Farmer’s Guide to Soybean Diseases. The American Phytopathological Society.

Pod and stem blight

Name	Pod and stem blight
Importance	medium
Pathogen	Diaporthe phaseolorum var. sojae
Geographical range	Midwest/Eastern US
Stage start	R5
Stage end	R8
Descriptions	Wet weather nearing harvest increases disease. Can increase risk of seed decays.
Symptoms	Black fungal specks in linear rows on the stems of mature soybean plants (pycnidia). Infected seedlings may have reddish-brown streaks near the soil line.
Where	On stem, pods, petioles, nodes, or seeds
Citation	Mueller, D., Wise, K., Sisson, A., Smith, D., Sikora, E., Bradley, C., and Roberston, A. 2016. A Farmer’s Guide to Soybean Diseases. The American Phytopathological Society.

Purple seed stain

Name	Purple seed stain
Importance	low
Pathogen	Cercospora kikuchii
Geographical range	Midwest/Eastern US
Stage start	VC
Stage end	R8
Descriptions	Purple discoloration of seed. Related to CLB. Warm, humid weather favors infection.
Symptoms	Distinct pink to dark-purple discoloration of seeds in small spots or entire seed surface.
Where	On seed
Citation	Mueller, D., Wise, K., Sisson, A., Smith, D., Sikora, E., Bradley, C., and Roberston, A. 2016. A Farmer’s Guide to Soybean Diseases. The American Phytopathological Society.

Viral

Alfalfa mosaic

Name	Alfalfa mosaic
Importance	low
Pathogen	Alfalfa mosaic virus
Geographical range	Midwest/Eastern US
Stage start	V3
Stage end	R6
Descriptions	More common in field borders and in fields near waterways. Alternative hosts are other legume crops, solanaceous crops. Can be transmitted by seed. Main vectors are aphids (15 different species, including soybean aphid).
Symptoms	Symptoms appear anytime during the growing season. Leaves are mottled in appearance ranging from bright yellow and dark green colors. Stunted plant growth. Seed coat NOT mottled.
Where	Leaves, overall growth
Citation	Mueller, D., Wise, K., Sisson, A., Smith, D., Sikora, E., Bradley, C., and Roberston, A. 2016. A Farmer’s Guide to Soybean Diseases. The American Phytopathological Society.

Bean pod mottle

Name	Bean pod mottle
Importance	medium
Pathogen	Bean pod mottle virus (Comovirus)
Geographical range	Midwest/Eastern US
Stage start	R1
Stage end	R6
Descriptions	Favorable conidtions are during rapid plant growth and cool temperatures. Vectored by bean leaf beetles. Other sources are by perennial weed host and infected seed.
Symptoms	Yellow and green mottled areas on leaves. Leaves puckered, blistered, or distorted. Decreased pod size and number.
Where	Leaves, pods, and seeds
Citation	Mueller, D., Wise, K., Sisson, A., Smith, D., Sikora, E., Bradley, C., and Roberston, A. 2016. A Farmer’s Guide to Soybean Diseases. The American Phytopathological Society.

Soybean mosaic

Name	Soybean mosaic
Importance	medium
Pathogen	Soybean mosaic virus (Potyvirus)
Geographical range	Midwest/Eastern US
Stage start	R1
Stage end	R6
Descriptions	Concern is mostly reduced seed quality. Cool temperatures and high aphid populations lead to increased infection. Spread is primarily from planting infected seed.
Symptoms	Mosaic patterns with light and green areas on leaves. Chlorosis, lesions, and puckered/curled leaves.
Where	Young and rapidly growing leaves
Citation	Mueller, D., Wise, K., Sisson, A., Smith, D., Sikora, E., Bradley, C., and Roberston, A. 2016. A Farmer’s Guide to Soybean Diseases. The American Phytopathological Society.

Soybean vein necrosis

Name	Soybean vein necrosis
Abbr	SVNV
Importance	medium
Pathogen	Soybean Vein Necrosis Virus
Geographical range	Midwest/Eastern US
Stage start	R1
Stage end	R6
Descriptions	Anywhere in canopy. Transmitted by thrips . Drier years favor thrips.
Symptoms	Yellow lesions begin near leaf veins. Lesions form red-brown spots/patches (1/4-1/2 inch in diameter). Death of plant tissue.
Where	Generally along major leaf veins
Citation	Mueller, D., Wise, K., Sisson, A., Smith, D., Sikora, E., Bradley, C., and Roberston, A. 2016. A Farmer’s Guide to Soybean Diseases. The American Phytopathological Society.

Tobacco ringspot virus

Name	Tobacco ringspot virus
Importance	low
Pathogen	Nepovirus
Geographical range
Stage start	R3
Stage end	R8
Descriptions	Warm, dry weather favors disease development. Transmitted by infected seed and sometimes insect and nematode vectors.
Symptoms	Leaf distortion and discoloration. Distorted and lesions on the petioles. Stems may display shepherd’s crooking. Dead and brittle flowers and buds.
Where	End of the stems, leaves, and buds
Citation	Mueller, D., Wise, K., Sisson, A., Smith, D., Sikora, E., Bradley, C., and Roberston, A. 2016. A Farmer’s Guide to Soybean Diseases. The American Phytopathological Society.

Tobacco streak

Name	Tobacco streak
Importance	low
Pathogen	Tobacco streak virus (Ilarvirus)
Geographical range	North Central US
Stage start	R3
Stage end	R8
Descriptions	Transmitted by thrips and by infected seed.
Symptoms	Dark spots on pods. Development of extra axillary braches and leaf and bud proliferation/shepherds crook. Leaf mosaic and dwarfing. Stunted growth and delayed maturity. Seed disoloration.
Where	Pods and stems and seed discoloration
Citation	Mueller, D., Wise, K., Sisson, A., Smith, D., Sikora, E., Bradley, C., and Roberston, A. 2016. A Farmer’s Guide to Soybean Diseases. The American Phytopathological Society.