Agronomic

Emergence

Category	Agronomic
Name	Emergence
Symptoms	poor germination

Foliar fertilizer injury

Category	Agronomic
Name	Foliar fertilizer injury
Symptoms	Leaf tissue burnt and white/yellow-orange especially near the tips. Leaves curled. Reduced plant growth and yield, though many fields outgrow injury. Burns may be caused by UAN or urea application.
References	https://www.mississippi-crops.com/2014/06/14/diagnosing-nutrient-deficiencies-in-mississippi-soybeans/ 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.

Fungicide injury

Category	Agronomic
Name	Fungicide injury
Symptoms	Leaf tissue between veins turns brown and yellow. May be confused with Sudden Death Syndrome. Occurs mostly in the upper canopy (but new leaves, emerged post-application would show no symptoms).

Growth regulator

Category	Agronomic
Name	Growth regulator
Symptoms	Leaves are stippled, with small white dots, turning red or yellow over time. Other virus-like symptoms with mottling/cupping.

Herbicide injury

Category	Agronomic
Name	Herbicide injury
Symptoms	Herbicide injury symptoms vary depending on the type of herbicide or surfactant used. PPO inhibitor herbicides: Leaf spots and leaf blights that often mimic diseases. Glufosinate: Interveinal chlorosis, looks similar to sudden death syndrome. ACCase inhibitors: injury along leaf veins. Residual herbicides: Early season can resemble seedling blight.

Planting

Category	Agronomic
Name	Planting

Stand

Category	Agronomic
Name	Stand

Environmental

Drought

Category	Environmental
Name	Drought
Symptoms	Leaves wilt and there is stunted/reduced plant growth. There is an increase in pod an flower abortion, thus reducing yield. Symptoms are similar to that of soybean cyst nematode.
References	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.

Flooding

Category	Environmental
Name	Flooding
Symptoms	Plants may become stunted and and yellow. Plants may die, especially during V1-V2 and R1-R3. There may be an increase in root rot diseases.
References	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.

Frost

Category	Environmental
Name	Frost
Symptoms	Early season: Seedlings appear damaged or killed, brown and necrotic. Water-soaked lesions and discolored hypocotyls indicate plant death. Similar looking to seedling blight. Late season: Plants appear wilted and are completely frozen. Leaflets appear die and may fall off prematurely. Yield is reduced by smaller seed size and harvest of immature/green seed. May be confused with several diseases where leaves remain attached with wilting.
References	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.

Hail

Category	Environmental
Name	Hail
Symptoms	Hail tatters leaves and causes bruises or break stems. May lead to plant lodging later in the season. Yield loss may occur depending on the timing of the hail event (R1-R8 are greatest losses). Hail damage may allow for pathogens a point of entry into the plant.
References	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.

Lightning

Category	Environmental
Name	Lightning
Symptoms	Circular patch of dead plants with clear edges. Plants in the center will be dead, with less damage as you move to the edge. Damage may be up to 30 feet (9 m) in diameter. Weeds in the area will also be killed.
References	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.

Lodging

Category	Environmental
Name	Lodging
Symptoms	Excessive vegetative growth leads to plants falling over. Lodging reduces light penetration in the canopy. Lodging during R3-R5 growth stage is most detrimental and impacts yield by reducing harvestability.
References	https://www.ilsoyadvisor.com/on-farm/ilsoyadvisor/agronomy-how-manage-lodging-risk

Soil Crusting

Category	Environmental
Name	Soil Crusting
Symptoms	Soil crusting may occur after a hard rainfall. Soil crusting causes bent, twisted, or death to seedlings. Similar looking to some seedling diseases and herbicide injury.
References	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.

Sunscald

Category	Environmental
Name	Sunscald
Symptoms	Leaves in the uppermost canopy turn brown-tan on the underside. May be confused with symptoms of Cercospora leaf blight.
References	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.

Nutrient Disorders

Iron

Category	Nutrient Disorders
Name	Iron
Symptoms	Occurs mostly on soils that contain lime, are calcareous with high pH. Also casued by inability for plants to uptake iron. Youngest leavesshow interveinal chlorosis, yellowing between green veins. Plant growth may be stunted. Similar to manganese deficiency and SCN damage.
References	https://cropwatch.unl.edu/soils/soybean-nutrients https://www.mississippi-crops.com/2014/06/14/diagnosing-nutrient-deficiencies-in-mississippi-soybeans/

Magnesium

Category	Nutrient Disorders
Name	Magnesium
Symptoms	Pale green plants with interveinal pale mottling (yellow). Necrosis begins on the underside of leaves. Symptoms appear first on older, fully expanded leaves.
References	https://cropwatch.unl.edu/soils/soybean-nutrients

Manganese

Category	Nutrient Disorders
Name	Manganese
Symptoms	Leaves are pale yellow with chlorotic interveinal tissue. Necrosis in interveins over time. Plants look pale green-yellow, with some brown necrosis.
References	https://cropwatch.unl.edu/soils/soybean-nutrients https://www.mississippi-crops.com/2014/06/14/diagnosing-nutrient-deficiencies-in-mississippi-soybeans/

Nitrogen

Category	Nutrient Disorders
Name	Nitrogen
Symptoms	Leaves pale green-yellow and maybe brown in older leaves. Symptoms appear first on older, fully expanded leaves. May be related to poor soybean nodulation.
References	https://cropwatch.unl.edu/soils/soybean-nutrients

Phosphorus

Category	Nutrient Disorders
Name	Phosphorus
Symptoms	Spindly appearance with small, rounded leaflets and stunted growth. In some cases P deficient beans appear dark green-blue. Not easily identifiable without leaf tissue testing.
References	https://www.mississippi-crops.com/2014/06/14/diagnosing-nutrient-deficiencies-in-mississippi-soybeans/

Potassium

Category	Nutrient Disorders
Name	Potassium
Symptoms	Green leaves with chlorotic leaf margins and begin to die from the tip. Leaves curl upward and some brown interveinal tissue. Symptoms occur more severely on older leaves, with localized symptoms. Middle to lower canopy, but can occur in upper canopy. Occurs in patches in fields. More prevalent in dry years.
References	https://cropwatch.unl.edu/soils/soybean-nutrients https://www.mississippi-crops.com/2014/06/14/diagnosing-nutrient-deficiencies-in-mississippi-soybeans/

Sulfur

Category	Nutrient Disorders
Name	Sulfur
Symptoms	Plants green to yellow with some brown or bronze necrosis. Leaves pale green to yellow with no prominent veins or necrosis.
References	https://cropwatch.unl.edu/soils/soybean-nutrientshttps://www.mississippi-crops.com/2014/06/14/diagnosing-nutrient-deficiencies-in-mississippi-soybeans/

Zinc

Category	Nutrient Disorders
Name	Zinc
Symptoms	Pale green plants with interveinal mottling and necrosis. Dark green veins. Symptoms first in older, fully expanded leaves.
References	https://cropwatch.unl.edu/soils/soybean-nutrients

Unknown

Green soybean syndrome

Category	Unknown
Name	Green soybean syndrome
Symptoms	All parts of the plant (pods, leaves, stems, etc.) remain green and show delayed maturity. Buds may proliferate. Seeds often remain green and swollen, with reduced pod and seed numbers. May cause yield loss depending on the tiing of the infection. May be caused by pesticide applications or artificial lighting.
References	https://soybeanresearchinfo.com/soybean-disease/green-stem-disorder/ Harbach, C. J., Allen, T. W., Bowen, C. R., Davis, J. A., Hill, C. B., Leitman, M., … & Hartman, G. L. (2016). Delayed senescence in soybean: Terminology, research update, and survey results from growers. Plant Health Progress, 17(2), 76-83.

Green stem disorder

Category	Unknown
Name	Green stem disorder
Symptoms	Plants have green, fleshy stems and pods at the time of crop maturity. Non-senescent stems with dehisced petioles and normal mature pods. Individual plants and patches of plants may be affected. May be caused by stink bugs feeding, fungicide appl, viruses, or late emergence.
References	https://soybeanresearchinfo.com/soybean-disease/green-stem-disorder/ Harbach, C. J., Allen, T. W., Bowen, C. R., Davis, J. A., Hill, C. B., Leitman, M., … & Hartman, G. L. (2016). Delayed senescence in soybean: Terminology, research update, and survey results from growers. Plant Health Progress, 17(2), 76-83.