Soybean disease control
John D. Mueller
Soybean is susceptible to many diseases beginning with seed rots and seedling diseases. As the plant develops and matures leaf, pod, and stem diseases often become common, especially during wet growing seasons. In some cases a disease can kill individual plants: or in the case of a severe epidemic of Stem Canker kill more than 50% of the plants in a field.
Leaf diseases such as Brown Spot can have little or no effect upon yield while other leaf diseases such as Frogeye Leaf Spot or Asian Soybean Rust can prematurely defoliate an entire field, drastically reducing yield. Detection and accurate identification of diseases can be difficult.
Many of the symptoms such as interveinal necrosis occur with several diseases. When an accurate identification is needed you should work through your county agent to utilize their expertise to either identify the problem on site or submit an accurate sample to the Clemson University Plant Problem Clinic.
Seedling diseases
Profit margins on soybean are too narrow to allow replanting of most fields due to poor stands. Growers get only one chance to establish the desired stand in a field and must minimize the potential for seedling diseases. Seedling diseases can occur over a wide range of conditions and plant growth stages. Included in the seedling disease category are: Seed rots that occur after seed has been planted but prior to germination; Seedling decay which occurs between germination and emergence; and Damping off which occurs in the first 2- to 3-weeks after emergence.
Accurately identifying the microbial species that has caused any of these problems is difficult: especially if the plant has already died. However, differentiating among the three major post-emergence pathogens can be fairly predictable depending upon the temperature and moisture conditions.
Seed rots occurring prior to germination. They are typically caused by a combination of various fungi and bacteria. The seed is frequently of low vigor. When low vigor is the problem additional seed treatments with fungicides will not improve stands. Seed rots often occur when seed are placed under stresses. These can be temperature extremes, too hot or too cold, or in very wet or dry conditions. Unfortunately, avoiding early planting dates or planting prior to either extremely hot and dry or cool and wet periods as well as using only high quality seed are the only way to avoid Seed Rots.
Pre-emergence Damping Off is typically caused by Pythium spp. in cool wet weather. Seeds begin germination but either due to poor seed quality or diseases never produce a seedling capable of cracking the soil surface. The Pythium fungus is normally a problem only in early planted soybean.
Post-emergence Damping Off is typically caused by Pythium species in cool, wet weather. A sunken lesion or canker develops near the soil line and appears to be a “wet rot”. In warmer or drier weather Rhizoctonia solani is more typically the cause of Post-emergence Damping off. There is still a lesion or canker near the soil line but it does not have the appearance of a wet rot.
Phytophthora Root Rot is caused by the fungus Phytophthora sojae. It is a common disease in the Midwest on their heavy soils which retain moisture. It is much less common in the Coastal Plains soils of South Carolina since their sand content allows for better drainage and higher temperatures than those favored by the fungus.
The clay soils of the Piedmont are more favorable to Phytophthora Root Rot than the sandy soils of the Coastal Plain. Phytophthora Root Rot typically is detected from plants in the seedling stage to plants in early pod set. Plants have leaves that exhibit interveinal necrosis and a dark brown discoloration progresses up the outside and the inside of the stem.
Root systems are normally extensively decayed. Resistance is common in lower maturity group soybean varieties but is not as common in Maturity Group VI, VII, and VIII soybeans. The existence of races of the fungus makes utilization of resistance difficult.
Seedling Disease Control: To minimize all types of seedling diseases use a seed-treatment fungicide on seed with less than 80 percent germination and on all soybean seed to be planted under cool, wet conditions. The fungi which cause most seedling diseases over winter on debris from the previous crop. Use a seed-treatment fungicide when soybeans are planted with conservation tillage since vigorous stands are critical to early weed control.
Seed treatments do not compensate for poor seed quality. The fungicides available for seed treatments are listed in Table 1. Remember the fungicides which control Rhizoctonia solani do not control Pythium or Phytopthora species and vice-versa. Therefore the most effective seed treatments usually include at least two fungicides with one from each category. Closely follow the manufacturer’s label for doses and application procedures in treating seed. Efficacy of all seed treatments requires thorough mixing of the fungicide and seed so that all seed are adequately treated. Do not use treated seed for food, feed or oil.
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Asian Soybean Rust
Asian soybean rust has received a lot of attention since it was first discovered in the United States in the late Fall of 2004.
Fig. 1. Premature defoliation due to Asian Soybean Rust in the center plot.
It is caused by the fungus Phakopsora pachyrhizi. Asian Soybean Rust can only survive for extended periods of time on live host tissue. Therefore it cannot overwinter anywhere above the freeze line (approximately Tampa Bay, Florida) since its primary hosts, kudzu and soybean, will be dead and defoliated.
Each year new inoculum (rust spores) must blow in from infected areas such as south Florida, Mexico, or South America to start the disease over again in the Southeastern United States. Infections and sporulation by Asian Soybean Rust are favored by cooler, wet weather. Hot dry weather will stop the spread of the fungus. Asian Soybean Rust reached South Carolina in Mid-August in 2005 and 2006. However, periods of hot, dry weather in September seem to have slowed down infection rates and spread so that overall affects on yield were minimal.
The extreme drought conditions in Georgia and South Carolina slowed the spread of rust in 2007 and 2008. Rust was not detected until mid-September in 2007 and 2008. Figures 2a through 2h show the distribution of rust in the United States on the first date it was detected in South Carolina each year and the final distribution of rust in the United States each year (maps courtesy of http://www.sbrusa.net/).
 Fig. 2a. Distribution of ASR in the U.S. on August 15, the first date in 2005 ASR was found in South Carolina. |
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Management of Asian Soybean Rust is primarily through the use of foliar fungicides applied during flowering. A list of fungicides available for rust management in South Carolina is presented in Tables 2 and 3. Growers need to be very careful when choosing fungicides for soybean disease control. Some fungicides such as Topsin 4.5 FL provide excellent control of many diseases but are not effective against rust (Table 2).
Be sure to consult your county agent and web sites for updated information. The sentinel plot system run in South Carolina by Clemson University and funded by APHIS-CSREES-RMA provides almost daily updates on the spread of rust in South Carolina and issues a rust spray advisory for each week. Currently there are no varieties with functional resistance to Asian Soybean Rust.
Up to date information on the spread of Asian Soybean Rust is present at http://www.sbrusa.net/. More general information on Asian Soybean Rust is available at http://www.ces.ncsu.edu/depts/pp/soybeanrust/. If you would like to be added to the South Carolina electronic news note on rust contact your county agent or Dr. John D. Mueller via email at jmllr@clemson.edu.
Bacterial Blight
Bacterial Blight is caused by the bacterium Pseudomonas syringae pv. glycinea. This bacterium over winters on infected soybean tissue on the soil surface but can also be seed borne. Infections occur through stomates and wounds. Very young plants can be infected. Symptoms appear first as water-soaked lesions. Yellow halos develop around the lesions and the center of the lesions turn brown and eventually fall out. Therefore in advanced cases of the disease the leaves appear tattered or shot-holed. When infected tissue is place in water under a microscope bacterial will be visible streaming out of the lesions.
Disease development is favored by cool (75 to 79o F), wet and rainy weather. Like many diseases spread or development will slow or halt in hot dry weather. Bacterial Blight resembles Brown Spot but Bacterial Blight will move up the plant much quicker. Management of Bacteria Blight is through the use of high quality seed, avoiding excessive stands and narrow rows, and destroying or plowing under crop residues in the fall. Use of foliar antibiotic sprays has usually not been successful in controlling Bacterial Blight.
Bacterial Pustule
Bacterial Pustule is caused by the bacterium Xanthomonas campestris pv. glycines. Like Bacterial Blight it over winters on seed and in soybean debris. Disease development is favored by warm (86 to 91o F), wet weather with splashing rains. Unlike Bacterial Blight hot weather will not slow down the development of Bacterial Pustule.
Bacterial Blight and Bacterial Pustule may occur on the same leaf. Symptoms include raised areas on the underside of the leaves in which pustules eventually form. Bacterial pustules can easily be mistaken for pustules caused by Asian Soybean Rust. You will need help from your county agent to differentiate the two diseases or a sample will need to be sent to the Plant Problem Clinic. To minimize the risk from Bacterial Pustule plant high quality seed of resistant varieties and destroy soybean debris in the Fall. Use of foliar antibiotic sprays has usually not been successful in controlling Bacterial Pustule.
Downy Mildew
Downy Mildew is caused by the fungus Peronospora manshurica. This disease is very common in South Carolina and usually occurs during periods of three or more days of high humidity or thunderstorms in July and August. The disease may appear suddenly and spread rapidly. The inoculum is airborne and blows in from other affected areas. Only young leaves are susceptible so the disease will first appear in the top of the canopy.
Symptoms include small light green to yellow lesions on the upper leaf surface that have a white tuft of the fungus visible on the bottom side of the leaf. You may need a magnifying glass to see this white tuft. Pods can be infected but show no symptoms. Infected seed have a white crust present on the seed. When the weather becomes dry the white tuft will shrivel up and fall off but the yellow spots on the leaf surface will remain. Although the yellow spots may cover a large area of some leaves, yield losses due to Downy Mildew are minimal. The yellow spots are often mistaken for Asian Soybean Rust.
Asian Soybean Rust can be differentiated from Downy Mildew because only Asian Soybean Rust has pustules present on the bottom side of the yellow spots. Asian Soybean Rust does not have the mycelial tufts on the undersides of lesions. Spraying fungicides for Downey Mildew is usually not cost effective unless beans are being grown for seed. Seed treatment fungicides can help eliminate seed-borne Downy Mildew. Soybean varieties vary greatly in their susceptibility to Downy Mildew but information on current varieties is difficult to obtain.
Brown Spot
Brown Spot is caused by the fungus Septoria glycines. Brown Spot may be the most common soybean disease in South Carolina. It occurs in almost every field. It overwinters on seed and in crop debris. Severity of Brown Spot increases as plants mature and senesce. Symptoms of Brown Spot are rather indistinct. Lesions are irregular in shape and size but tend to enlarge into “brown spots”. Brown spot starts in the lower canopy and moves up the plant with time.
Very small fruiting structures called pycnidia are present in the larger lesions. They are impossible to see without a dissecting microscope. They resemble the pycnidia present with Pod and Stem Blight but do not occur in rows. Infected leaves often senesce and drop off of the plant early. However, yield losses are usually minimal since photosynthesis in these leaves was no longer efficient. Control is through the use of high quality seed and destruction of soybean debris in the fall. Several fungicides will control brown spot but usually yield losses are low and do not warrant control (see Table 2). Varieties seem to vary in their levels of susceptibility to Brown spot, but there are no reliable ratings available for use.
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Frogeye Leaf Spot
Frogeye Leaf Spot is caused by the fungus Cercospora sojina. This fungus overwinters on infected seed and in soybean debris. Symptoms of Frogeye Leaf Spot are very distinct with generally circular lesions with a white to grey center and dark reddish-brown margins. As the lesions age the center may turn darker. Symptoms occur in midseason and then become more severe after flowering.
Varieties vary in their susceptibility from almost immune to moderately susceptible to extremely susceptible. In the right weather conditions, very overcast or rainy weather, extremely susceptible cultivars can be almost totally defoliated by Frogeye Leaf Spot. Control is by planting resistant varieties, using high quality seed and destroying soybean debris in the Fall. Avoid extremely susceptible cultivars. Foliar fungicide sprays after flowering can help limit the severity of Frogeye Leaf Spot but are economical only on very susceptible varieties when disease severity is high (see Table 2).
Cercospora Blight & Purple Seed Stain
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Cercospora Blight & Purple Seed Stain are caused by the fungus Cercospora kikuchii. This fungus overwinters in debris and seedcoats. Symptoms of Cercospora Blight can be difficult to distinguish from nutrient deficiencies or ozone damage.
Symptoms typically appear only late in the growing season with premature defoliation of the upper canopy during pod fill. Leaves appear to be a reddish-purple or bronze especially after flowering with the discoloration worsening as plants mature. Reddish-purple lesions may develop on major veins on the underside of leaves. Pods may exhibit round reddish-purple lesions which later turn purple/black.
Infected seeds will exhibit a distinctly purple stain over some or all of the seed coat. If infected seed are to be planted they need to be treated with a fungicide. Several foliar fungicides are effective in controlling this disease but predicting severity so that preventive sprays can be made is difficult (see Table 2). Some varieties appear to be less susceptible than others: however, reliable lists of resistant varieties are not available.
Target Spot
Target Spot is caused by the fungus Corynespora cassicola. This disease appears to be on the increase in the last several years in the Southeastern United States. It has an extremely wide host range and infects many plant species. The fungus overwinters on soybean debris and seed. It can survive in a fallow field for two years. Symptoms include round to irregular lesions which may have alternating light and dark rings (a target spot) similar to that caused by Alternaria species on soybean and many vegetable crops.
The disease appears to be favored by wet weather in mid to late season and severity is worse in fields where the canopy has been filled. Many varieties exhibit excellent resistance to Target Spot, however a reliable rating for many varieties is not available. Where possible choose a resistant variety. Use of foliar fungicides has not been a reliable control method for Target Spot.
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Red Crown Rot
Red Crown Rot, Cylindrocladium root rot, and CBR are all common names for a basal stem rot caused by the fungus Cylindrocladium parasiticum (formerly Cylindrocladium crotalaria). This fungus can persist in the soil for several years. Infection occurs in the taproot and spreads up the stem 8 to 12 inches, killing all roots and infected stem tissue. The first visible sign or symptom of Red Crown Rot is yellowing of the leaves and eventual interveinal necrosis. This symptom is also common to Red Crown Rot, and Stem Canker.
Like Southern Blight, dead plants may be scattered throughout a field or in small clumps or oval shaped areas in the direction of tillage. The scattered dead plants often lead to an overestimation of the damage present in a field. Masses of small, ball-shaped, reddish-orange fruiting structures (perithecia) of the fungus usually develop on stems at the soil surface. Red crown rot infects many species of legumes as well as other plants; it can be spread by soil moved on plows and cultivation equipment and by surface water. No chemical controls are available. Some varieties appear more susceptible than others, but information on currently popular varieties is usually lacking. Red Crown Rot is usually considered to have little economic impact in South Carolina. Rotation to non-legume crops is the only economical control.
Southern Blight
Southern Blight or Southern Stem Blight is caused by the fungus Sclerotium rolfsii. This fungus survives in the soil on organic matter, is favored by hot weather stress and is recognized by the appearance of white mold on stems at the soil surface causing rotting of stems and roots. Small tan to brown, “mustard seed-like” fruiting bodies (sclerotia) are produced within the white mold growth. The disease is most often seen in June, July and August during very wet periods. Southern Blight is very common in fields with moderate to high levels of root-knot nematode. The first sign or symptom of the disease is interveinal necrosis in the leaves. This symptom is also common to Red Crown Rot, and Stem Canker.
Diagnosis as Southern Blight usually includes the presence of the white mold and sclerotia at the base of the stem. Plants with white mold surrounding the base of the stem often die. Dead plants may be scattered throughout a field or in small clumps or oval shaped areas in the direction of tillage. The scattered dead plants often lead to an overestimation of the damage present in a field. Although yield losses can be detected, in general Southern Blight often appears worse than it really is and serious economic yield losses are not common in South Carolina. The sclerotia serve as survival structures for the fungus allowing it to survive over severe winters and for several years in the same field without a host. Rotation with other crops such as cotton or corn will help reduce levels of inoculum in the field. Peanut is a host for S. rolfsii and will increase disease levels. No chemical controls are available.
Anthracnose
Anthracnose is caused by the fungus Colletotrichum truncatum. This fungus overwinters in seed and infected soybean debris. Symptoms of Anthracnose are not well defined. Soybean is susceptible to Anthracnose at all growth stages. Brown lesions develop on stems, pods, and even leaves. Infected petioles will form lesions below the leaflets and cause the leaflets to wither and drop. The remaining petiole often takes on a “shepherd’s crook” shape.
The fungus produces a black fruiting structure (an acervulus) similar in size to a rust pustule. However, unlike a rust pustule black hairs (setae) are present on the structure. The acervulus is diagnostic for this fungus and can be observed under a 20X magnifying glass or a dissecting scope. Anthracnose typically becomes apparent during flowering and becomes worse as the plants senesce. Wet weather during pod fill will increase the severity of Anthracnose. Use of foliar fungicides applied after flowering will help alleviate the severity of Anthracnose (see Table 2). Plowing under crop debris and rotation to a crop other than soybean will reduce inoculum levels. Resistant varieties are not available.
Pod and Stem Blight
Pod and Stem Blight is caused by the fungus Diaporthe phaseolorum var. sojae (sexual stage) also known as Phomopsis longicolla (asexual stage). Black fruiting structures (pycnidia) that resemble very small, rounded volcanoes are present in rows on affected stems and are more scattered on pods and leaves. Pycnidia of Pod and Stem Blight resemble those of Brown Spot which occurs on leaves. Pycnidia of Brown Spot do not occur in rows nor are they normally found on stems.
Pycnidia of Pod and Stem Blight can be differentiated from Anthracnose because the pycnidia occur in rows whereas the acervuli of Anthracnose are more scattered and exhibit hairs (setae) which the pycnidia do not have. Like many fungal diseases this fungus overwinters on debris and can infect seed. Rotation with corn and plowing down residue will help reduce inoculum levels. Resistant varieties are not available. Use of foliar fungicides applied after flowering will help alleviate the severity of Pod and Stem Blight (see Table 2).
Charcoal Rot
Charcoal rot is caused by the fungus Macrophomina phaseolina. This fungus can survive several years in dry soil as microsclerotia, a specialized fungal survival structure. However, microsclerotia can only survive several months in wet soil. This fungus can infect plants from the seedling stage all the way to maturity. Symptoms in seedlings include stunting and reddish brown to black discoloration in the lower stem. Taproots and lower stems of older plants can be reddish to black. Small black flecks or streaking are visible under the bark. These sclerotia are a survival structure and considered diagnostic for the fungus.
Mid- to late-season Charcoal Rot is often linked to hot dry conditions. Charcoal Rot has a very wide host range including over 500 crop species; however, rotation with most crops and deep tillage will reduce inoculum levels. Rotation with corn will not reduce inoculum levels. Use of irrigation will often minimize the stress caused by the fungus. Resistant varieties are not available. Use of foliar fungicides is not recommended since it is difficult to predict disease severity and often the stresses which increase infection levels and make symptoms visible limit yields.
Southern Stem Canker
Southern Stem Canker is caused by the fungus Diaporthe phaseolorum var. caulivora. This disease appeared throughout the Southern and Southeastern United States in the early 1980’s and caused severe yield losses in many fields. The epidemic was quickly brought under control with the utilization of resistant varieties in subsequent years.
Today Southern Stem Canker is not common in South Carolina. Most maturity group V, VI, VII, or VIII cultivars are resistant. In the Mid-South Stem Canker is still a problem. Susceptible varieties are often grown for several years when weather does not favor disease development. In subsequent years if weather is favorable for disease development yield losses can be catastrophic in a given field. The fungus can survive for at least a year on infected debris and may be introduced to a field on infected seed. Symptoms of stem canker begin in the mid- to lower stem nodes in July and August and move upward as the plant matures. Small, elliptical, dark brown cankers usually appear on the main stem near the base of nodes.
Cankers enlarge as the disease spreads. Cankers can girdle the stem. Leaves of infected plants sometimes exhibit a flagging symptom with interveinal chlorosis and then die. Other diseases such as Red Crown Rot and Southern Blight cause similar symptoms. The leaves hanging on the plant after dying give the appearance of frost injury. To control stem canker turn under infected soybean residue as soon as possible; rotate to non-host crops (e.g. corn or cotton) for one or two years; and plant resistant varieties where possible. Although most varieties in maturity group V or later are resistant, growers should double check all information on the varieties they choose to be sure they are resistant to Southern Stem Canker. Foliar fungicides are not effective in controlling Southern Stem Canker in South Carolina.
Places to obtain more information
Printed literature
The “Compendium of Soybean Diseases” Fourth Edition is edited by G. L. Hartman, J. B. Sinclair, and J.C. Rupe. Published by the American Phytopathological Society Press. Can be ordered at 1-800-328-7560. This book contains excellent short articles on all of the known diseases and nematodes that affect soybean. Each section is written by the expert on that problem. Probably the most technically detailed information available.
Web pages
The North Carolina State University Soybean Disease Information Notes are located at: http://www.ces.ncsu.edu/depts/pp/notes/Soybean/soybean_contents.html
The University of Georgia Soybean Extension Page is at:
http://comodities.caes.uga.edu/fieldcrops/soybeans/
The University of Missouri Soybean Disease Management bulletin G4452 is available at: http://extension.missouri.edu/explore/agguides/crops/g04452.htm
The University of Arkansas Soybean Disease Images Library is at:
http://www.aragriculture.org/diseases/image_library/row_crop/soybean/
The University of Arkansas Soybean Handbook Disease Section (Chapter 11- MP197) is at: http://www.uaex.edu/other_areas/publications/HTML/MP-197.asp
A Soybean Disease Atlas prepared by the Southern Soybean Disease Workers is available at: http://cipm.ncsu.edu/ent/SSDW/soyatlas.htm
Table 1. Fungicides available for use in controlling seedling diseases on soybean.
Brand Name |
A.I. |
Fungi Controlled |
Rate |
ApronMaxx RFC |
Mefenoxam 3.46% |
Fusarium spp., Rhizoctonia solani |
1.5 fl oz per cwt |
ApronMaxx RTA |
Mefenoxam 1.01% |
Fusarium spp., Rhizoctonia solani |
5.0 fl oz per cwt |
ApronMaxx RTA + Moly |
Mefenoxam 1.02% |
Fusarium spp. |
5.0 fl oz per cwt |
CruiserMaxx |
Mefenoxam 1.7% |
Fusarium spp. |
3.0 fl oz per cwt |
Trilex AL Flowable Fungicide |
Trifloxystrobin 1.275% |
Pythium spp. |
5.7 fl oz per cwt |
Trilex Flowable Fungicide |
Trifloxystrobin 22% |
Rhizoctonia solani |
0.32 fl oz per cwt |
Vitavax CT Flowable Fungicide |
Carboxin 5.7% |
Rhizoctonia solani |
12.0 fl oz per cwt |
Vitavax M Flowable Fungicide |
Carboxin 5.7% |
Rhizoctonia solani |
12.0 fl oz per cwt |
Vitavax MDC |
Captan 23.9% |
Rhizoctonia solani |
2 oz per bushel |
The Label is the law. Always read and follow all pesticide label restrictions.
Do not use treated seed for food, feed or oil purposes. Do not graze or feed livestock on forage or hay grown from treated soybean seed. All treated seed must be colored with an EPA-approved dye which imparts an unnatural color to the seed to help prevent the inadvertent use of treated seed as food for man or feed for animals.
Table 2. Fungicides with FIFRA Section 3 labels for use on soybean in South Carolina. For a list of specific diseases controlled by each fungicide please see a product label.
Brand Name |
Active Ingredient |
Rate (fl oz/acre) |
Number of |
Diseases Controlled |
Bravo Weather Stik |
Chlorothalonil |
24-32 |
3 (96) |
Rust + other diseases |
Bravo Ultrex |
Chlorothalonil |
24-32 |
3 (96) |
Rust + other diseases |
Echo 720 |
Chlorothalonil |
24-32 |
3 (96) |
Rust + other diseases |
Echo 90DF |
Chlorothalonil |
24-32 |
3 (96) |
Rust + other diseases |
Equus 720 SST |
Chlorothalonil |
24-32 |
3 (96) |
Rust + other diseases |
Equus DF |
Chlorothalonil |
24-32 |
3 (96) |
Rust + other diseases |
Domark 230 ME |
Tetraconazole |
4-5 |
1 (10) |
Rust + other diseases |
Folicur 3.6 SC |
Tebuconazole |
4.0 |
2(8) |
Rust |
Headline 2.09 EC |
Pyraclostrobin |
6.0 |
2(24) |
Rust + other diseases |
Laredo 25EC |
Myclobutanil |
4.0-8.0 |
2 (16) |
Rust + other diseases |
Proline |
Prothioconazole |
2.5-3.0 |
3(9) |
Rust + Powdery mildew |
Quadris 2.08 EC |
Azoxystrobin |
6-15 |
1(15) |
Rust + other diseases |
Quilt 1.67SC |
Azoxystrobin + Propiconazole |
14-20 |
2 (40) |
Rust + other diseases |
Stratego 250EC |
Propiconazole + Trifloxystrobin |
5.5 – 10.0 |
2 (20) |
Rust + other diseases |
Tilt 250EC |
Propiconazole |
4.0-8.0 |
2 (12) |
Rust + other diseases |
Bumper 41.8EC |
Propiconazole |
4.0-8.0 |
2 (12) |
Rust + other diseases |
Alto 100SL |
Cypraconazole |
2.75-4.0 |
2 (8.0) |
Rust + other diseases |
Quadris Xtra |
Azoxystrobin + Cypraconazole |
4.0 – 6.8 |
2 (8.0) |
Rust + other diseases |
TOPSIN 4.5 FL |
Thiophanate-methyl |
10-20 |
2(40) |
Other diseases |
TOPSIN 70 WP |
Thiophanate- methyl |
0.5 – 1.0 lbs/acre |
2(2 lbs) |
Other diseases |
The Label is the law. Always read and follow all pesticide label restrictions.
Table 3. Fungicides with FIFRA Section 18 labels for use on soybean in South Carolina only for controlling Asian Soybean Rust.
Product |
Active |
Rate |
Number of Applications/ |
Fungicide Class |
Caramba |
Metconazole |
8.2 -9.6 |
2(19.2) |
Triazole |
Punch |
Fluzilazole |
4.0 |
2 (8.0) |
Triazole |
Topguard 125SC |
Flutriafol |
7.0 |
2 (14) |
Triazole |