Soybean disease control
John D. Mueller
Soybean is susceptible to many diseases beginning shortly after planting 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 on 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 on several diseases. When an accurate identification is needed, you should work through your county agent to use their expertise to either identify the problem on site or submit an accurate sample to the Clemson University Plant Problem Clinic.
Since profit margins on soybean are so narrow, replanting of most fields because of poor stands is not an option. 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. Seedling diseases include 1) Seed rots, which occur after seed has been planted but prior to germination; 2) Seedling decay, which occurs between germination and emergence; and 3) Damping-off, which occurs in the first 2- to 3-weeks after emergence. Accurately identifying the causal agent of these problems is difficult, especially if the plant has already died. Differentiating among the three major post-emergence pathogens can be readily predicted depending on the temperature and moisture conditions.
Seed rots occurring prior to germination. They are typically caused by a combination of various fungi and bacteria. Low vigor seed are more prone to seed rots. When low vigor seed is used seed treatments with fungicides will not improve stands. Seed rots often occur when seed are planted under stress, such as 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 to germinate but never produce a seedling capable of cracking the soil surface because of poor quality seed or diseases. Pythium spp. are 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 on heavy soils that retain moisture in the Midwest. It is much less common in the Coastal Plains soils of South Carolina, since the 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 (Maturity Groups II and III), but is not as common in Maturity Group VI, VII, and VIII soybeans. The existence of races of the fungus makes use of resistance difficult.
Seedling Disease Control: The fungi which cause most seedling diseases over winter on debris from the previous crop. To minimize all of the types of seedling diseases, use a seed treatment fungicide on seed with less than 80% germination and on all soybean seed to be planted under cool, wet conditions. Seed treatments do not compensate for poor seed quality. Use a seed treatment fungicide when soybeans are planted with conservation tillage, since vigorous stands are critical to early season weed control. The fungicides available for seed treatments are listed in Table 1. Remember the fungicides that control Rhizoctonia solani do not control Pythium or Phytophthora 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.
Fig. 1. Premature defoliation due to Asian Soybean Rust in the center plot. |
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. It is caused by the fungus Phakopsora pachyrhizi. Asian Soybean Rust can survive for extended periods of time only 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 killed and defoliated by freezing temperatures. 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 cool, 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. Rust was not detected until mid-September in 2007 and was eventually found in only half of the counties it had been detected in during 2005 and 2006. The final distribution of rust in South Carolina for 2005, 2006, and 2007 is shown in Figures 2a, 2b, and 2c, respectively (maps courtesy of http://www.sbrusa.net/). In 2005 and 2006 the distribution of rust was extensive. However, as shown in Figure 3 the drought restricted the distribution of rust in 2007.
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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 is present in Table 3. New fungicides are receiving labels this spring and summer and other fungicides are undergoing label changes. In spite of their extensive usage during the past three years, fungicides that contain tebuconazole (Folicur, Uppercut, Orius) do not have a current label for use on soybean. 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 every 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. In advanced cases of the disease, the leaves have a tattered or shot-hole appearance. When infected tissue is placed in water under a microscope, bacteria are 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 Bacterial Blight is through the use of high quality seed, avoiding high plant density caused by excessive seeding rates and narrow rows, and destroying or plowing under crop residues in the fall. No foliar antibiotic sprays are labeled for use in soybean.
Bacterial Pustule
Bacterial Pustule is caused by the bacterium Xanthomonas campestris pv. glycines. Like Bacterial Blight it overwinters 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 which eventually form pustules. Bacterial pustules can easily be mistaken for pustules caused by Asian Soybean Rust. You will need help from your county agent to differentiate these 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. No foliar antibiotic sprays are labeled for use in soybean.
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 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 the susceptibility of current varieties is difficult to obtain.
Brown Spot
Brown Spot is caused by the fungus Septoria glycines. Brown Spot occurs in nearly every field and 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. 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 yield losses are usually low and do not warrant control. Varieties seem to vary in their levels of susceptibility to Brown spot, but reliable ratings are not available.
Fig. 2. Frogeye leaf spot on a susceptible cultivar. |
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 become more severe after flowering. Varieties vary in their susceptibility from almost immune to moderately susceptible to extremely susceptible. In the right weather conditions, i.e. 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.
Cercospora Blight & Purple Seed Stain
Fig. 3. Bronzing and leaf discoloration due to Cercospora leaf blight. |
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 have a reddish-purple or bronze color, 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 that later turn purple/black. Infected seeds will exhibit a distinctly purple stain over some or all of the seed coat. Infected seed need to be treated with a fungicide before planting. Several foliar fungicides are affective in controlling this disease, but predicting severity so that preventive sprays can be made is difficult. 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 over 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 reliable ratings for many varieties are not available. Where possible choose a resistant variety. Use of foliar fungicides has not been a reliable control method for Target Spot.
Fig. 4. Target spot.
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Fig. 5. Target Spot damage. Left side of field exhibits dead leaves and defoliation on a susceptible variety; right side of field is a resistant variety.
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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 Southern Blight, 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, Southern Stem Blight, or Sclerotium 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. 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 of 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. Soybean is susceptible to Anthracnose at all growth stages. Symptoms of Anthracnose are not well defined. 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” appearance. The fungus produces a black fruiting structure (an acervulus) similar in size to a rust pustule. 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. 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 (sexualstage) 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.
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. Microsclerotia, however, can only survive several months in wet soil. This fungus can infect plants from the seedling stage 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 minimize drought stress and subsequent damage caused by the disease. Resistant varieties are not available. Use of foliar fungicides is not recommended since it is difficult to predict disease severity. Disease severity is correlated to stress levels. These stresses are very difficult to predict in time for a fungicide spray to effective.
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 by planting resistant varieties. Today Southern Stem Canker is not common in South Carolina. Most maturity group V, VI, VII, and 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 moves up 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. |
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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 labeled only to control diseases other than Asian Soybean Rust on soybean in South Carolina.
Brand Name |
Common Name |
Rate (fl oz/acre) |
Number of |
Common names of diseases controlled |
Topsin 4.5 FL
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Thiophanate-methyl |
10-20 |
2(40) |
Anthacnose, Brown Spot, Cercospora Leaf Blight, Diaporthe Pod & Stem Blight, Frogeye, Purple Seed Stain |
The Label is the law. Always read and follow all pesticide label restrictions. |
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Table 3. Fungicides for management of soybean rust.
Brand Name |
Common Name |
Rate (fl oz/a)b |
Number of Applications/year and Maximum (fl/oz/a)/year |
Fungicide Class and (FRAC Code)a |
Labelc |
Bravo, Echo, Equus |
Chorothalonil |
24-32 |
3 (96) |
Nitrile (M4) |
Section 3 |
Quadris |
Azoxystrobin |
6.2-15.4 |
2 (90.0) |
Strobilurin (11) |
Section 3 |
Headline |
Pyraclostrobin |
6.0-12.0 |
2 (24) |
Strobilurin (11) |
Section 3 |
Tilt, PropiMax, Bumper |
Propiconazole |
4.0-8.0 |
2 (12) |
Triazole (3) |
Section 3 |
Folicur, Uppercut, Orius, |
Tebuconazole |
3.0-4.0 |
2 (8) |
Triazole (3) |
Expired/Pending renewal |
Laredo EC |
Myclobutanil |
4.0-8.0 |
2 (16) |
Triazole (3) |
Section 3 |
Domark |
Tetraconazole |
4.0-6.0 |
1 (6.0) |
Triazole (3) |
Section 3 |
Stratego |
Propiconazole + Trifloxystrobin |
5.5-10.0 |
2 (20) |
Strobilurin + Triazole (3 & 11) |
Section 3 |
Quilt |
Azoxystrobin + Propiconazole |
14-20 |
2 (40.0) |
Strobilurin + Triazole (3 & 11) |
Section 3 |
Alto |
Cypraconazole |
2.75-4.0 |
2 (8.0) |
Triazole (3) |
Section 18 |
Quadris Xtra |
Azoxystrobin + Cypraconazole |
4.0 |
2 (8.0) |
Strobilurin + Triazole (3 & 11) |
Section 18 |
Caramba |
Metconazole |
8.2-9.6 |
2 (19.2) |
Triazole (3) |
Section 18 |
Punch |
Fluzilazole |
4.0 |
2 (8.0) |
Triazole (3) |
Section 18 |
Charisma |
Fluzilazole + Famoxodone |
9.0 |
2 (18.0) |
Triazole (3) |
Pending |
Topgaurd |
Flutriafol |
7.0 |
2 (14.0) |
Triazole (3) |
Section 18 |
a Combinations of a strobilurin and a triazole may provide increased control and residual activity.
b Higher rates provide greater residual activity and may reduce the need for later sprays.
c Section 3 labels are for general use and not contingent on emergency conditions. Section 18 labels are temporary and expire on various dates unless renewed or replaced by Section 3 labels. Pending indicates that these materials may be labeled as Section 3 or Section 18 materials. Fungicides labeled as Section 18 materials are restricted use pesticides when used on soybean, regardless of what the accompanying label material may say and you must have the Section 18 label in your possession if using these materials. Read label for plant back restrictions on all materials used, some are very restrictive.