How To Read A Disease Alert
Welcome to CropVoice University
The information on this page is gathered from public sources and informed by InnerPlant’s data and experts to create a one-stop, authoritative source on crop disease.
CVU Disease
Disease alerts give in-the-moment warning of infection for specific fields when InnerSoy plants signal the presence of disease, along with a clear indication about whether a spray is needed.
Disease Alerts
Disease alerts give in-the-moment warning of infection for specific fields when InnerSoy plants signal the presence of disease
If you’d like to see how CropVoice can help your farm detect white mold before symptoms are scoutable on your farm, call (877) 418-2062 or send us a note at cropcoice@innerplant.com.
If you’d like to see how CropVoice can help your farm detect white mold before symptoms are scoutable on your farm, call (877) 418-2062 or send us a note at cropvoice@innerplant.com.
How To Read A Scouting Report
Welcome to CropVoice University
The information on this page is gathered from public sources and informed by InnerPlant’s data and experts to create a one-stop, authoritative source on crop disease.
CVU Disease
The CropVoice weekly scouting report provides the most comprehensive and actionable information for disease management.
You get a text and email tailored to your specific area weekly during peak fungal season. Scouting reports put disease risk front and center, then the full picture below: environmental conditions, tissue sampling, field scouting, modeling, and images. Everything you need, nothing you don’t.
Weekly Report
The CropVoice weekly scouting report provides the most comprehensive and actionable information for disease management.
- Simple disease risk forecast
- Tissue sampling to determine which pathogens are present
- Images from our scouts in the field
- Environmental conditions that inform disease pressure
- Field notes from local agronomists
- Disease forecast maps for the upcoming week
If you’d like to see how CropVoice can help your farm detect white mold before symptoms are scoutable on your farm, call (877) 418-2062 or send us a note at cropcoice@innerplant.com.
If you’d like to see how CropVoice can help your farm detect white mold before symptoms are scoutable on your farm, call (877) 418-2062 or send us a note at cropvoice@innerplant.com.
Efficacy Of Foliar Fungicides In Soybeans
Welcome to CropVoice University
The information on this page is gathered from public sources and informed by InnerPlant’s data and experts to create a one-stop, authoritative source on crop disease.
CVU Disease
This fungicide efficacy table, published by the Crop Protection Network, provides research-based ratings to help farmers and agronomists choose the right fungicide for controlling foliar diseases in soybeans — including frogeye leaf spot, white mold, brown spot, and more. Ratings reflect disease control performance tested across multiple years and locations by the North Central Regional Committee on Soybean Diseases (NCERA-137).
Not sure if disease is present in your area? CropVoice™ by InnerPlant can alert you to confirmed fungal infections near your fields before symptoms are visible — helping you decide if and when to spray.
If you’d like to see how CropVoice can help your farm detect white mold before symptoms are scoutable on your farm, call (877) 418-2062 or send us a note at cropcoice@innerplant.com.
If you’d like to see how CropVoice can help your farm detect white mold before symptoms are scoutable on your farm, call (877) 418-2062 or send us a note at cropvoice@innerplant.com.
Sudden Death Syndrome
Welcome to CropVoice University
The information on this page is gathered from public sources and informed by InnerPlant’s data and experts to create a one-stop, authoritative source on crop disease.
CVU Disease
Sudden Death Syndrome (SDS), caused by the soil-borne fungus Fusarium virguliforme, is a significant threat to soybean production across the United States. The pathogen impacts root health and can lead to severe defoliation and significant yield loss. While SDS is widespread, risk of severe yield impact is highest in compacted fields with disease history, heavy residue, poor drainage, and high populations of Soybean Cyst Nematode (SCN).
Disease Cycle
- Fusarium virguliforme overwinters as chlamydospores in root debris, soil and crop residue.
- Chlamydospores germinate under cool, wet soil conditions early in the season, infecting soybean roots shortly after planting.
- The fungus colonizes the roots, limiting root development, and produces a phytotoxin that moves up the plant xylem.
- Phytotoxin causes interveinal chlorosis and necrosis in leaves, with symptoms first appearing after flowering.
- Premature defoliation occurs, leaving only green petioles attached to the stem.
Fusarium virguliforme overwinters in infected crop and root residue. Early in the growing season, when the crop is exposed to wet soil conditions and cool temperatures (mid-60s℉), residual fungal spores, or chlamydospores, can infect and colonize soybean roots. Infection can begin as early as germination or just after crop emergence.
In addition to attacking the root system, the fungus produces a potent phytotoxin that is transported from the roots up the xylem to the leaves. Initial leaf symptoms appear as yellow spots between the major leaf veins (interveinal chlorosis), while the veins remain green.
High soil moisture, from rain or irrigation, and warm temperatures during the reproductive stages accelerate the production and movement of the phytotoxins, increasing symptom severity.
Tissue between the veins becomes brown and necrotic, causing the leaf to curl and drop prematurely. Leaf petioles remain attached to the stem. Hot, dry conditions can delay or stop SDS symptom development.
Defoliation reduces the plant’s ability to photosynthesize during the critical pod-fill period, which can cause shriveled and small seeds, and significant yield reduction.
Impact
SDS is consistently one of the most economically devastating soybean diseases in North America. In 2025, SDS led to an estimated yield loss of 49 million bushels, costing U.S. farmers over $512M (based on the USDA’s 2025/26 marketing year average price). Its widespread occurrence and ability to cause rapid, severe defoliation during the critical pod-filling stages result in significant yield loss annually.
The yield impact of SDS is directly related to the timing and severity of foliar symptom development, particularly how early the plant loses its ability to fill pods.
Yield loss projections:
- Early onset of severe foliar symptoms (R3-R4) ➜ Significant yield loss and shriveled seeds
- Late season onset (R6) or low severity ➜ Minimal yield loss
Managing Sudden Death Syndrome
The best way to combat SDS is an integrated management approach that focuses on reducing early-season root infection and mitigating secondary stresses like SCN.
Before planting: Reduce your risk
If you have a field history of SDS, avoid or address high-risk field areas that are low, compacted and have poor drainage. Work with your seed dealer to select soybean varieties that have genetic resistance to SDS, particularly for high-risk fields. While SDS persists through corn rotations, crop rotation to reduce SCN can help as SCN potentially increases SDS severity.
Fungicidal seed treatments can help reduce early-season root infection, and are most effective when combined with resistant varieties, improved drainage and reduced compaction.
Note, early planting can put soybeans at higher risk of SDS as infection typically occurs when soybeans are exposed to cool, moist soil conditions early in the season. Prioritize planting fields with a history of severe SDS later in the planting season for that reason.
Early Reproductive (R1-R5): Monitor fields
Scout your fields for the characteristic interveinal yellow spots in the foliage. Once these symptoms appear, the fungus has already infected the plant roots and released the phytotoxins, making fungicides applied at this stage ineffective against SDS. Disease severity can worsen if wet conditions persist.
Accurate diagnosis is challenging, as SDS foliar symptoms are similar to other diseases. To verify SDS, inspect both the roots and stems. Split open a root or base of the stem – the disease causes a distinct grayish-brown discoloration of the lower stem and taproot’s cortical tissue, while the center pith remains white. In very moist conditions, the base of the stem may also have bluish-white mold growth.
Late Reproductive (R6-R8): Track late-season infection
Monitor fields for severe defoliation and the presence of petioles still attached to the stem. Note any fields or varieties that show severe symptoms for future management decisions.
If you’d like to see how CropVoice can help your farm detect white mold before symptoms are scoutable on your farm, call (877) 418-2062 or send us a note at cropcoice@innerplant.com.
If you’d like to see how CropVoice can help your farm detect white mold before symptoms are scoutable on your farm, call (877) 418-2062 or send us a note at cropvoice@innerplant.com.
Septoria Brown Spot
Welcome to CropVoice University
The information on this page is gathered from public sources and informed by InnerPlant’s data and experts to create a one-stop, authoritative source on crop disease.
CVU Disease
Septoria brown spot, caused by the fungus Septoria glycines, is the most common soybean foliar disease. The disease can be found across most soybean-producing regions in the U.S., especially where soybeans are grown continuously.
Septoria brown spot thrives in warm, wet weather. Infection often occurs soon after planting, with symptoms becoming visible first in the lower canopy.
Disease Cycle
- Septoria glycines overwinters in infected crop residue
- Conidia spread by wind and rain to lower leaves of new plants
- Leaf lesions appear starting in the lower canopy. Infected leaves turn yellow, causing defoliation.
- Infection moves up plant canopy if warm, humid conditions persist
- Sporulation from lesions cause secondary infections
Septoria brown spot overwinters in infected soybean residue. In warm (60-85 ºF), humid conditions, Septoria brown spot fungal spores (conidia) spread by wind, rain, or irrigation. The infection starts in the lower canopy.
Symptoms typically first appear on young plants as small dark brown spots, sometimes with a yellow halo, on the unifoliolate leaves and will move further up the plant if warm, wet conditions continue. Lesions can spread to both the top and bottom of leaves, petioles and stems. Spots merge to form irregular brownish blotches. Infected leaves (typically in the lower to mid-canopy) turn yellow and drop. Symptoms for Septoria brown spot can easily be confused with bacterial blight. However, bacterial blight typically shows up on young leaves higher in the canopy while Septoria brown spot begins lower in the canopy.
The disease usually stops progressing in hot, dry conditions. New spores from infected plants can cause secondary infections in the same field.
Impact
Septoria brown spot can lead to yield reduction and premature defoliation, though significant yield loss is uncommon in the U.S. In 2025, Septoria brown spot resulted in an estimated yield loss of 1.5 million bushels, costing farmers over $15M (based on the USDA’s 2025/26 marketing year average price).
Yield loss from Septoria brown spot depends on how far up the canopy the disease progresses during podfill. The greatest yield loss is typically caused by severe early-season infection that leads to premature defoliation that spreads beyond the lower canopy.
Yield loss projections:
- Early and severe infection ➜ Reduce photosynthesis and slight yield loss
- Late season or low severity ➜ Minimal or no yield loss
Managing Septoria Brown Spot
Before planting: Reduce your risk
Understand which fields will be at highest risk for severe infection. Fields in low-lying areas with poor drainage or with a history of severe Septoria brown spot will likely be where Septoria shows up first. Additionally, fields with a history of other conditions like severe soybean cyst nematode damage or Fusarium root rot are at higher risk for Septoria brown spot.
While there are no varieties completely resistant to Septoria brown spot, if Septoria brown spot has been an issue for you in the past, work with your seed dealer to select soybean varieties that are less susceptible.
Vegetative stages (V1-Vn): Monitor for initial symptoms
Keep an eye out for warm, humid conditions, which are ideal for Septoria brown spot development. Monitor the lower canopy for the first signs of small, dark purple or brown spots.
One simple way to detect Septoria brown spot early is by using CropVoice. CropVoice sends you Disease Alerts when your crops are infected by monitoring daily InnerSoy™soybean plants engineered to signal when infected by fungus, like Septoria brown spot.
Reproductive Stages (R1-R5): Evaluate infection spread and treat if necessary
Check for disease becoming more severe and symptoms progressing up the plant. You can apply foliar fungicides from R3-R5 to limit infection spread to the middle to upper canopy during podfill. However, unless you see severe, early-season symptoms, applying fungicide might not be economically justified.
Late Reproductive (R6-R8): Track late-season infection
Monitor fields for premature defoliation. At this stage, fungicide application offers no benefit. Track the performance of your varieties for future crop rotations.
If you’d like to see how CropVoice can help your farm detect white mold before symptoms are scoutable on your farm, call (877) 418-2062 or send us a note at cropcoice@innerplant.com.
If you’d like to see how CropVoice can help your farm detect white mold before symptoms are scoutable on your farm, call (877) 418-2062 or send us a note at cropvoice@innerplant.com.
Cercospora Leaf Blight
Welcome to CropVoice University
The information on this page is gathered from public sources and informed by InnerPlant’s data and experts to create a one-stop, authoritative source on crop disease.
CVU Disease
Cercospora leaf blight, caused by the pathogens Cercospora flagellaris or Cercospora kukuchii, is a fungus that can infect soybeans and threaten both the yield and seed quality of soybean crops. While it is found across most of the U.S. where soybeans are grown, Cercospora leaf blight is most commonly seen in the Southern and Midwestern states. Impact to yield is typically highest in the Southern U.S., where the warm, humid conditions are most conducive.
Disease Cycle
- Mycelia overwinter in infected crop residue
- When conditions are humid and between 75-80° F mycelia produce conidia, which spread by wind, rain splash, or irrigation
- Conidia infect soybean leaves, petioles and stems. In the presence of sunlight, the pathogen produces a toxin called cercosporin which causes plant cells to rupture
- Leaf lesions develop as leathery, bronze or purple discoloration in the upper canopy and progress to premature defoliation
- Sporulation from lesions cause secondary infections
- Purple seed stain may occur if pods become infected
Cercospora leaf blight survives over winter in infected soybean residue. As temperatures rise to between 75-80° F and humidity increases, Cercospora leaf blight mycelia produce fungal spores, or conidia, that spread to new soybean tissue by wind, rain or irrigation.
Infected leaves, petioles, and stems may begin to show signs of disease late in the season, after the R1 growth stage. The pathogen that causes Cercospora leaf blight produces a toxin, called cercosporin, in the presence of sunlight, which causes plant cells to rupture. Because sunlight is critical for the toxin formation, leaves in the upper canopy typically show the most severe symptoms. Initial symptoms show as a leathery, purple or bronze discoloration on the uppermost leaves, petioles and stems. This discoloration can look like sun scorch.
Lesions can eventually lead to premature defoliation, leaving only petioles attached to the stem. Premature defoliation reduces the plant’s ability to photosynthesize, which can cause shriveled and small seeds, and reduced yield.
If warm, humid conditions persist, new spores from infected plants can cause secondary infections. Fields with dense canopies are particularly vulnerable to severe late-season Cercospora leaf blight.
If infection spreads to the seed pods, the seed coat near the hilum will show a pink or purple discoloration, otherwise known as purple seed stain. If Cercospora leaf blight reaches this final stage, there’s a much higher chance it will survive into the next season.
While infected seeds can also carry the pathogen into the next year’s crop (not depicted on the graphic above), transmission from seed-to-seedling is less common.
Impact
Cercospora leaf blight can cause significant yield loss and reduced seed quality. In 2025, Cercospora leaf blight and purple seed stain led to an estimated yield loss of 6.1 million bushels, costing farmers over $63M (based on the USDA’s 2025/26 marketing year average price).
The yield impact of Cercospora leaf blight is directly related to the severity and timing of the upper-canopy defoliation.
Yield loss projections:
- Early and severe defoliation ➜ Significant yield loss and reduced seed quality
- Late season (after R6) or low severity ➜ Minimal yield loss
Managing Cercospora Leaf Blight
The best way to combat Cercospora leaf blight is an integrated management approach that includes in-season monitoring and timely in-season intervention when appropriate.
Before planting: Reduce your risk
When selecting soybean seed, choose certified, pathogen-free seed. If you have a field history of Cercospora leaf blight, work with your seed dealer to select soybean varieties that are more resistant to Cercospora leaf blight.
Late vegetative through early reproductive: Start monitoring conditions
Keep an eye out for warm (between 75-80° F), humid conditions and extended leaf wetness hours (more than 8 hours/day), which are ideal for Cercospora leaf blight development.
One simple way to detect Cercospora leaf blight before symptoms are visible is by using CropVoice. CropVoice scouting reports combine daily monitoring of InnerSoy™ (soybean plants engineered to signal when infected by fungus, like Cercospora leaf blight) with advanced models to forecast disease risk. CropVoice sends you a Disease Alert when there is confirmed Cercospora leaf blight infection near your fields
Reproductive (R3-R5): Actively monitor and manage your fields
Scout the upper canopy of your soybeans for the characteristic purple or bronze discoloration. Efficacy of fungicide application is highest when applied before significant symptoms appear.
Before applying fungicide, consider your farm’s specific risk factors, such as whether your fields have a history of Cercospora leaf blight and if the soybean varieties you planted are resistant to Cercospora leaf blight. Your cost of fungicide product and application will also determine the ROI of any application. Again, in many regions in the Upper Midwest, yield impact of Cercospora leaf blight is limited.
If you do decide to apply a foliar fungicide, ensure the product you select is labeled for use against Cercospora leaf blight and is effective. Recently, there has been increasing fungicide resistance documented for QoI (Group 11).
Late Reproductive (R6-R8): Track late-season infection
Monitor fields for severe defoliation, particularly in the upper canopy. While very severe Cercospora leaf blight can be confused with Sudden Death Syndrome, damage from Cercospora leaf blight typically starts in the upper canopy with reddish-purple or bronze discoloration, instead of the interveinal yellowing that characterizes Sudden Death Syndrome.
At this stage, fungicide application offers limited return on investment. Note any fields with Cercospora leaf blight and track the performance of your varieties for future crop rotations.
If you’d like to see how CropVoice can help your farm detect white mold before symptoms are scoutable on your farm, call (877) 418-2062 or send us a note at cropcoice@innerplant.com.
If you’d like to see how CropVoice can help your farm detect white mold before symptoms are scoutable on your farm, call (877) 418-2062 or send us a note at cropvoice@innerplant.com.
Frogeye Leaf Spot
Welcome to CropVoice University
The information on this page is gathered from public sources and informed by InnerPlant’s data and experts to create a one-stop, authoritative source on crop disease.
CVU Disease
Frogeye leaf spot, caused by the fungus Cercospora sojina, is a foliar soybean disease found across the United States and Eastern Canada. Because frogeye leaf spot is easily confused with other foliar diseases, proper scouting and diagnosis is critical. The disease thrives in warm, humid conditions with extended leaf wetness, either from frequent rainfall, overhead irrigation, or overcast conditions that prevent the canopy from drying
Disease Cycle
- Cercospora sojina pathogen survives in crop residue for 2 years or more
- Conidia spread to the canopy through rain droplets and wind
- Lesions appear and enlarge, which may lead to leaf blight and premature defoliation
- Stem and pod lesions may develop late in season
- Infected tissue results in crop residue with conidia
Frogeye leaf spot survives in the residue of previous soybean crops for two years or more. Splashing water droplets from rain and wind spread conidia, or fungal spores, up into the canopy. While frogeye leaf spot can infect at any soybean growth stage, young leaves are most susceptible and symptoms typically appear after flowering in the upper canopy.
Initial symptoms appear as small, dark spots that spread into lesions about a ¼-inch wide with gray-brown centers and a characteristic brownish-red margin (giving it the name “frogeye leaf spot”). Individual leaf spots can blend and appear as irregular blighting patterns. Later in the season, infection can develop on stems and pods, appearing as long, thin lesions on the stem and sunken, reddish brown lesions on the pod. Severe infection can lead to discolored and cracked seed.
New spores from infected plants can spread to healthy plants in the same field. The frogeye leaf spot cycle repeats multiple times throughout a single growing season, building up disease pressure and inoculum that will overwinter.
While infected seeds can also carry the pathogen, transmission through seed is not common.
Impact
Risk from frogeye leaf spot is highest in fields that have a history of frogeye leaf spot disease. More susceptible soybean varieties are at risk as infected residue can more easily build up to infect the following year’s crop.
Per the most recent national disease loss survey, frogeye leaf spot was estimated to reduce U.S. soybean production by 5.4M bushels in 2025, or roughly $56.9M in farm-gate value lost (based on the USDA’s 2025/26 marketing year average price).
Frogeye leaf spot’s effect on yield can vary greatly, depending on disease timing, varietal susceptibility to disease, and weather conditions during soybean reproductive stages:
- Early reproductive infection + severe disease + warm, humid weather ➜ up to ~35% yield loss with extensive leaf blighting
- Late infection (after R5.5) or low severity ➜ minimal yield loss
Managing Frogeye Leaf Spots
To combat frogeye leaf spot, combine long-term management approaches while addressing in-season when risk to yield is highest. Frogeye leaf spot can be easily confused with other foliar disease or injury. Knowing the difference will help you apply the best management strategy.
Before planting: Reduce your risk
Identify areas that will be at highest risk for the upcoming season by looking at fields with previous soybean crops that were flagged for significant frogeye leaf spot pressure. If possible, choose resistant soybean varieties, like those with the Rcs3 resistance gene. In order to reduce the risk of introducing frogeye leaf spot into new fields, select certified seed.
Late vegetative through early reproductive: Start monitoring conditions
Because frogeye leaf spot can infect at any growth stage, it’s important to keep an eye out for warm, humid conditions and extended leaf moisture early in the season.
CropVoice is one tool that can help to keep tabs on frogeye leaf spot pressure. Weekly scouting reports from CropVoice combine daily monitoring of InnerSoy™ (soybean plants engineered to signal when infected by fungus like frogeye leaf spot) with advanced models to forecast frogeye leaf spot disease risk in your fields. CropVoice will send you a Disease Alert when there are active frogeye leaf spot infections near your fields, often before you see symptoms, so you can take action when it is warranted.
Early reproductive (R1-R4): Actively monitor and manage your fields
Risk to yield peaks and severe outbreaks occur early in the reproduction stages.
Unfortunately, frogeye leaf spot has become more resistant to commonly used fungicides over the last decade. Not all fungicides perform equally well against frogeye leaf spot. Resistance to Group 11 (QoI) fungicides is widespread, requiring farmers to take a more strategic approach. Consider using multiple modes of action, such as Group 3 or Group 7 fungicides.
Late reproductive (R5-7): Track late-season infection
Infection risk continues through the growing season, but yield impact is typically minimal if the disease begins after R5. Fungicide applications at this stage provide limited ROI. Make sure to note which fields had high frogeye leaf spot pressure and variety performance for your next soybean rotation.
If you’d like to see how CropVoice can help your farm detect white mold before symptoms are scoutable on your farm, call (877) 418-2062 or send us a note at cropcoice@innerplant.com.
If you’d like to see how CropVoice can help your farm detect white mold before symptoms are scoutable on your farm, call (877) 418-2062 or send us a note at cropvoice@innerplant.com.
White Mold
Welcome to CropVoice University
The information on this page is gathered from public sources and informed by InnerPlant’s data and experts to create a one-stop, authoritative source on crop disease.
CVU Disease
White mold, caused by the pathogen Sclerotinia sclerotiorum, is a fungus that can infect a wide range of broadleaf crops, including soybeans. This fungus is most common in regions that see cool, wet weather during flowering and dense canopies. These include parts of the Midwest, particularly the Upper Midwest.
Disease Cycle
- Sclerotia persist in soil
- Sclerotia germinate and form apothecia
- Apothecia release ascospores.
- Ascospores infect senescing petals rich in pectin (R1-R3). Infection spreads into stem nodes, triggering plant defense.
- Signs and symptoms appear: white mycelium, sclerotia, bleached stem lesions, wilt, lodging, plant death resulting in no seeds or poor pod fill.
- Sclerotia develop in or on stems and pods; drop to soil at harvest where they can persist up to 10 years
White mold survives in the soil as hardened, densely packed fungal tissue structures called sclerotia. These structures form inside or on infected soybean stems and drop into the soil where they can persist for 10 or more years.
When conditions are right, sclerotia release apothecia—small, mushroom-like structures that release airborne spores (ascospores) that typically infect the plant through senescing soybean flowers. Because sclerotia can produce multiple flushes of apothecia, infection pressure can persist through the flowering window.
Once spores colonize the internal stem or branch tissue, the pathogen destroys girdles the stem or branch, cutting off water and nutrient flow. Visible symptoms like wilting and signs like white mycelium typically appear 2-3 weeks after infection, which may lead to plant death.
White mold thrives in high-yield environments, specifically fields with a high plant population (particularly bush-type varieties), dense canopy, narrow row spacing, and moist soil. The crop is at highest risk when cool to moderate temperatures below 85 °F and sustained soil moisture coincide with flowering and canopy closure. A dense canopy creates its own humid microclimate, ideal for apothecia formation and infection.
Once spores colonize the internal stem or branch tissue, the pathogen destroys girdles the stem or branch, cutting off water and nutrient flow. Visible symptoms like wilting and signs like white mycelium typically appear 2-3 weeks after infection, which may lead to plant death.
White mold thrives in high-yield environments, specifically fields with a high plant population (particularly bush-type varieties), dense canopy, narrow row spacing, and moist soil. The crop is at highest risk when cool to moderate temperatures below 85 °F and sustained soil moisture coincide with flowering and canopy closure. A dense canopy creates its own humid microclimate, ideal for apothecia formation and infection.
Impact
White mold is one of the most economically destructive soybean diseases. In 2025, white mold was estimated to reduce U.S. soybean production by 17.7M bushels, meaning farmers lost over $184M in farm-gate value (based on the USDA’s 2025/26 marketing year average price).
Because white mold impacts seed quality, volume and yield, it doesn’t follow a simple straight-line yield loss relationship. Earlier infections on the lower stem cause heavier yield loss than later infection of the branches. Reduced seed fill (“shrunken” seeds) and seeds infected in pods (“mummy” seeds) can lead to lower crop yield and grade. Sclerotia contamination in grain loads can create dockage at the elevator.
Yield loss projections:
- 0–40% DIX ➜ minimal yield loss
- 40–65% DIX ➜ measurable yield decline
- Above ~65% DIX ➜ ~10 bushels lost/acre for every 10% DIX increase
*Disease severity index (DIX): a 0–100 score researchers use to rate white mold in a field that combines how many plants are infected with severity of each infection. Zero means no white mold, 100 means every plant is dead.
Managing White Mold
Because infected plants produce new sclerotia that can persist for a decade, eradication is difficult. Farmers will need a long-term management strategy instead of a single-season fix.
Before planting: Reduce your risk
Consider each field’s history with white mold, including observations of disease hot pots, yield maps, or aerial imagery. If you do have fields with a history of white mold, there are a few steps you can take to reduce your risk.
Wider row spacing (like 30”) can help keep the canopy open to reduce the moist microclimate where white mold thrives. Reducing seeding rate can also allow for greater airflow.
If you had severe white mold infection in previous seasons, post-harvest application of biological control may be worth considering to break down sclerotia and thus reduce infection in future seasons.
Unfortunately, no variety of soybean is fully resistant to white mold. Varieties differ in susceptibility, so if white mold is a problem in your fields, it may be worth considering less-susceptible varieties.
Vegetative stages (V1-V6): Look for sclerotia
While you are scouting, closely look at the soil surface to spot any sclerotia or emerging apothecia, which will help identify potential hotspots later in the season. Note that it is very easy to miss sclerotia since they are small, dark structures that can easily blend into the soil.
Early Reproductive (R1-R3): Consider CropVoice for early detection
One simple way to detect white mold before symptoms are visible is by using CropVoice. CropVoice scouting reports combine daily monitoring of InnerSoy™ (soybean plants engineered to signal when infected by fungus, like white mold) with advanced models to forecast white mold risk in your fields. CropVoice sends you a Disease Alert when there is confirmed white mold infection near your fields.
If white mold risk is high in your fields, the critical window to apply fungicide is between R1 and R3, when the plant is most vulnerable as flowers begin to senesce. Not all fungicides are created equal when it comes to efficacy against white mold, so check which products are most effective here.
Late Reproductive (R4-R6): Monitor symptoms and track hotspots for next year
Look for signs and symptoms like leaf wilting, bleached (white) stems or white mycelium that suggest active infection. The presence of sclerotia and mycelia (white fluffy growth) on the stems differentiates white mold from brown stem rot, sudden death syndrome, or stem canker.
Once signs and symptoms are visible, it is too late for a fungicide application to effectively control white mold. Make sure to note the GPS coordinates of white mold hotspots for your next soybean rotation.
1 Renfroe-Becton, Hope, Maria Oros, Adam M. Byrne, Martin I. Chilvers, Nathan Kleczewski, Daren S. Mueller, Kiersten A. Wise, and Damon L. Smith. 2026. “Meta-Analytic and Economic Evaluation of Fungicide Programs Applied for Managing Sclerotinia Stem Rot in Soybean Across the North Central United States.” PhytoFrontiers™ 6 (1). https://doi.org/10.1094/PHYTOFR-07-25-0068-R.
If you’d like to see how CropVoice can help your farm detect white mold before symptoms are scoutable on your farm, call (877) 418-2062 or send us a note at cropcoice@innerplant.com.
If you’d like to see how CropVoice can help your farm detect white mold before symptoms are scoutable on your farm, call (877) 418-2062 or send us a note at cropvoice@innerplant.com.