Each year the Wisconsin Field Crops Pathology Program conducts a wide array of fungicide tests on alfalfa, corn, soybeans, and wheat. These tests help inform researchers, practitioners, and farmers about the efficacy of certain fungicide products on specific diseases. This year we were a bit delayed in publishing the report, due to the challenges of COVID-19. However, we do appreciate your patience and hope you find the report useful in making decisions for the 2021 field season.
Mention of specific products in these publications are for your convenience and do not represent an endorsement or criticism. Remember that this is by no means a complete test of all products available. You are responsible for using pesticides according to the manufacturers current label. Some products listed in the reports referenced above may not actually have an approved Wisconsin pesticide label. Be sure to check with your local extension office or agricultural chemical supplier to be sure the product you would like to use has an approved label. Follow all label instructions when using any pesticide. Remember the label is the law!
https://badgercropdoc.com/wp-content/uploads/sites/5/2021/02/Screen-Shot-2021-02-04-at-3.52.22-PM.png14641132damonsmithhttp://badgercropdoc.com/wp-content/uploads/sites/5/2018/05/bcd-color-300x153.pngdamonsmith2021-02-04 22:16:262021-02-05 19:20:142020 Wisconsin Field Crops Pathology Fungicide Tests Summary Now Available
Damon Smith, Extension Field Crops Pathologist, Department of Plant Pathology, University of Wisconsin-Madison
Shawn Conley, Extension Soybean and Small Grains Agronomist, Department of Agronomy, University of Wisconsin-Madison
Roger Schmidt, Nutrient and Pest Management Program, University of Wisconsin-Madison
Figure 1. Sporecaster predictions for selected non-irrigated locations in Wisconsin for July 29, 2020.
Figure 1 illustrates the calculated risk of white mold for select Wisconsin locations for non-irrigated soybeans, as determined by Sporecaster for July 29, 2020. This means that if soybeans are flowering and the area between rows is filled in more than 50%, risk is just moderate in most locations of the state, with the exception of the far northeast portions of the state and Door County. This moderate risk indicates that there may not be apothecia present in fields in these locations at this time, with reduced risk of subsequent white mold development due to hot and dry conditions. Remember that this season, you have the ability to change the action threshold for each field in the app. Last season the action threshold was locked at 40%, which is still a reasonable threshold for Wisconsin. Thus, figure 1 risk is calculated based on 40%. You can tailor this threshold to your liking based on your prior knowledge of a field, or your acceptable risk level. Further tailored predictions for irrigated locations and locations planted to narrower row-spacing can be run by downloading the Sporecaster app to your smartphone.
As we move toward the end of the fungicide spray window at R3, a fungicide application might not be warranted at this time on non-irrigated fields. In irrigated fields, we are seeing higher risk and finding apothecia in irrigated fields in central locations. A fungicide spray might be warranted in this situation.
I’m Ready To Spray, What Should I use?
If the canopy has met threshold, soybeans are flowering, and your Sporecaster risk is high, then a fungicide might be warranted. If you have decided to spray soybeans for white mold, what are the best products to use? I have written extensively about this in a previous post which you can find HERE. Over the last several years we have run numerous fungicide efficacy trials in Wisconsin and in conjunction with researchers in other states. In Wisconsin, we have observed that Endura applied at 8 oz once between the R1 and R3 growth stages performs well. We have also observed that the fungicide Aproach applied at 9 fl oz at R1 and again at R3 also performs comparably to the Endura treatment. Other fungicide options also include Omega and Proline. You can view results of past fungicide evaluations for Wisconsin by CLICKING HERE. If you would like to run tailored estimations of return on investment for various fungicide programs, you can use another smartphone application called Sporebuster.
Damon Smith, Extension Field Crops Pathologist, Department of Plant Pathology, University of Wisconsin-Madison
Shawn Conley, Extension Soybean and Small Grains Agronomist, Department of Agronomy, University of Wisconsin-Madison
Roger Schmidt, Nutrient and Pest Management Program, University of Wisconsin-Madison
Figure 1. Sporecaster predictions for selected non-irrigated locations in Wisconsin for July 23, 2020.
Figure 1 illustrates the calculated risk of white mold for select Wisconsin locations for non-irrigated soybeans, as determined by Sporecaster for July 23, 2020. This means that if soybeans are flowering and the area between rows is filled in more than 50%, risk is just moderate in most locations of the state, with the exception of the far northern portions of the state and Door County. This moderate risk indicates that there may not be apothecia present in fields in these locations at this time, with reduced risk of subsequent white mold development due to hot and dry conditions. Remember that this season, you have the ability to change the action threshold for each field in the app. Last season the action threshold was locked at 40%, which is still a reasonable threshold for Wisconsin. Thus, figure 1 risk is calculated based on 40%. You can tailor this threshold to your liking based on your prior knowledge of a field, or your acceptable risk level. Further tailored predictions for irrigated locations and locations planted to narrower row-spacing can be run by downloading the Sporecaster app to your smartphone.
We are finding risk to be higher for irrigated locations. As expected, we found apothecia (Fig. 2) present in our irrigated research location on the Hancock Agricultural Research Station located in Hancock, Wisconsin. Irrigated environments are often highly conducive for white mold development.
I’m Ready To Spray, What Should I use?
Figure 2. An apothecium of the white mold fungus. The dime is included for size comparison.
If the canopy has met threshold, soybeans are flowering, and your Sporecaster risk is high, then a fungicide might be warranted. If you have decided to spray soybeans for white mold, what are the best products to use? I have written extensively about this in a previous post which you can find HERE. Over the last several years we have run numerous fungicide efficacy trials in Wisconsin and in conjunction with researchers in other states. In Wisconsin, we have observed that Endura applied at 8 oz once between the R1 and R3 growth stages performs well. We have also observed that the fungicide Aproach applied at 9 fl oz at R1 and again at R3 also performs comparably to the Endura treatment. Other fungicide options also include Omega and Proline. You can view results of past fungicide evaluations for Wisconsin by CLICKING HERE. If you would like to run tailored estimations of return on investment for various fungicide programs, you can use another smartphone application called Sporebuster.
Damon Smith, Extension Field Crops Pathologist, Department of Plant Pathology, University of Wisconsin-Madison
Shawn Conley, Extension Soybean and Small Grains Agronomist, Department of Agronomy, University of Wisconsin-Madison
Roger Schmidt, Nutrient and Pest Management Program, University of Wisconsin-Madison
Figure 1. Sporecaster predictions for selected non-irrigated locations in Wisconsin for July 14, 2020.
Figure 1 illustrates the calculated risk of white mold for select Wisconsin locations for non-irrigated soybeans, as determined by Sporecaster for July 14, 2020. This means that if soybeans are flowering and the area between rows is filled in more than 50%, risk ranges from medium in the southern and western regions of the state to high in the central and northeastern regions for the presence of apothecia and subsequent white mold development. Remember, canopy closure is critical in calculating the probability of apothecial presence and subsequent white mold risk. DON’T CHEAT when using Sporecaster at your own locations! Also remember that this season, you have the ability to change the action threshold for each field. Last season the action threshold was locked at 40%, which is still a reasonable threshold for Wisconsin. Thus, figure 1 risk is calculated based on 40%. You can tailor this threshold to your liking based on your prior knowledge of a field, or your acceptable risk level. Further tailored predictions for irrigated locations and locations planted to narrower row-spacing can be run by downloading the Sporecaster app to your smartphone.
I’m Ready To Spray, What Should I use?
If the canopy has met threshold, soybeans are flowering, and your Sporecaster risk is high, then a fungicide might be warranted. If you have decided to spray soybeans for white mold, what are the best products to use? I have written extensively about this in a previous post which you can find HERE. Over the last several years we have run numerous fungicide efficacy trials in Wisconsin and in conjunction with researchers in other states. In Wisconsin, we have observed that Endura applied at 8 oz once between the R1 and R3 growth stages performs well. We have also observed that the fungicide Aproach applied at 9 fl oz at R1 and again at R3 also performs comparably to the Endura treatment. Other fungicide options also include Omega and Proline. You can view results of past fungicide evaluations for Wisconsin by CLICKING HERE. If you would like to run tailored estimations of return on investment for various fungicide programs, you can use another smartphone application called Sporebuster.
Damon Smith, Extension Field Crops Pathologist, Department of Plant Pathology, University of Wisconsin-Madison
Shawn Conley, Extension Soybean and Small Grains Agronomist, Department of Agronomy, University of Wisconsin-Madison
Roger Schmidt, Nutrient and Pest Management Program, University of Wisconsin-Madison
Figure 1. Sporecaster predictions for selected non-irrigated locations in Wisconsin for July 9, 2020.
Figure 1 illustrates the calculated risk of white mold for select Wisconsin locations for non-irrigated soybeans, as determined by Sporecaster for July 9, 2020. This means that if soybeans are flowering and the area between rows is filled in more than 50%, risk ranges from medium to high for the presence of apothecia and subsequent white mold development. Remember, canopy closure is critical in calculating the probability of apothecial presence and subsequent white mold risk. DON’T CHEAT when using Sporecaster at your own locations! Tailored predictions for irrigated locations and locations planted to narrower row-spacing can be run by downloading the Sporecaster app to your smartphone.
I’m Ready To Spray, What Should I use?
If the canopy has met threshold, soybeans are flowering, and your Sporecaster risk is high, then a fungicide might be warranted. If you have decided to spray soybeans for white mold, what are the best products to use? I have written extensively about this in a previous post which you can find HERE. Over the last several years we have run numerous fungicide efficacy trials in Wisconsin and in conjunction with researchers in other states. In Wisconsin, we have observed that Endura applied at 8 oz once between the R1 and R3 growth stages performs well. We have also observed that the fungicide Aproach applied at 9 fl oz at R1 and again at R3 also performs comparably to the Endura treatment. Other fungicide options also include Omega and Proline. You can view results of past fungicide evaluations for Wisconsin by CLICKING HERE. If you would like to run tailored estimations of return on investment for various fungicide programs, you can use another smartphone application called Sporebuster.
Damon Smith, Extension Field Crops Pathologist, Department of Plant Pathology, University of Wisconsin-Madison
Shawn Conley, Extension Soybean and Small Grains Agronomist, Department of Agronomy, University of Wisconsin-Madison
Roger Schmidt, Nutrient and Pest Management Program, University of Wisconsin-Madison
Paul Mitchell, Extension Economist, Agricultural and Applied Economics, University of Wisconsin-Madison
Figure 1. Apothecia, small mushroom-like structures of the white mold fungus that give rise to spores, which infect soybean flowers
In Wisconsin, the first week of July brings us a heightened awareness of white mold in soybeans, and its management. Late planting in 2019, coupled with cool, wet conditions, meant that there were some areas significantly affected by white mold last season. These conditions led to susceptible bloom time lining up directly with weather conducive for the fungus.
Remember that the white mold fungus infects soybeans through open and senescing flowers, by spores that are born from small mushroom-like structures called apothecia (Fig. 1). Remember that if the bloom period gets extended due to cool weather, this can lead to an extended window for infection by the fungus.Often cool weather is a double whammy as it is good for the white mold fungus and slows down soybean crop development, thereby extending bloom.
While conditions have been hot and dry in parts of the state, other portions have seen wetter conditions. The white mold situation can change rapidly based on weather, thus anticipating favorable conditions for white mold, can help you protect your soybean crop.
Predicting White Mold
Figure 2. Sporecaster predictions for selected non-irrigated locations in Wisconsin for July 3, 2020.
The flowering growth stages are a critical time to manage white mold in-season. You can view a fact sheet and video on the subject. As you probably know, timing in-season fungicide sprays at the correct time during the soybean bloom period can be extremely difficult. To help solve this decision-making issue, models were developed at the University of Wisconsin-Madison in conjunction with Michigan State University and Iowa State University to identify at-risk regions which have been experiencing weather favorable for the development of white mold apothecia. These models predict when apothecia will be present in the field using combinations of 30-day averages of maximum temperature, relative humidity, and wind speed. Using virtually available weather data, predictions can be made in most soybean growing regions. To facilitate precise predictions and make the model user-friendly, we use Sporecaster smartphone application for Android and iPhone.
The purpose of the smartphone app is to assist farmers in making early season management decisions for white mold in soybean. The best time to spray fungicides for white mold is during flowering (R1 and R3 growth stages) when apothecia are present on the soil surface.
Sporecaster uses university research to turn a few simple taps on a smartphone screen into an instant forecast of the risk of apothecia being present in a soybean field, which helps growers predict the best timing for white mold treatment during the flowering period.
University research has indicated that the appearance of apothecia can be predicted using weather data and a threshold of percent soybean canopy row closure in a field. Based on these predictions and crop phenology, site-specific risk values are generated for three scenarios (non-irrigated soybeans, soybeans planted on 15″ row-spacing and irrigated, or soybeans planted on 30″ row-spacing and irrigated). Though not specifically tested we would expect row-spacings of 22 inches or less to have a similar probability response to fungicide as the 15 inch row-spacing.
The Sclerotinia apothecial models that underlie the Sporecaster prediction tool have undergone significant validation in both small test plots and in commercial production fields. In 2017, efficacy trials were conducted at agricultural research stations in Iowa, Michigan, and Wisconsin to identify fungicide application programs and thresholds for model implementation. Additionally, apothecial scouting and disease monitoring were conducted in a total of 60 commercial farmer fields in Michigan, Nebraska, and Wisconsin between 2016 and 2017 to evaluate model accuracy across the growing region. Across all irrigated and non-irrigated locations predictions during the soybean flowering period (R1 to early R4 growth stages) were found to explain end-of-season disease observations with an accuracy of 81.8% using the established probability thresholds now programmed in the app. We have made additional improvements for 2020, to further refine accuracy. So if you have used Sporecaster before, you might want to watch the embedded video above to learn about the changes that were made for 2020 and how to best use Sporecaster. If you want to learn more about the science of Sporecaster, check out the embedded video below.
Not only can users run predictions of risk during the soybean bloom period for any field, you can also set up visual maps to look at multiple sites simultaneously. An example for the state of Wisconsin can be found in figure 2, which represents risk for July 3, 2020 for non-irrigated soybeans. Currently, if soybeans are flowering, risk is moderate to low in the southern third of Wisconsin for non-irrigated soybeans. And higher for flowering soybeans in the northern portions of the state. Check back to this blog regularly as I will post maps like these with interpretation of risk for Wisconsin as we move through the season.
What to Spray for White Mold?
If you have decided to spray soybeans for white mold, what are the best products to use? Over the last several years we have run numerous fungicide efficacy trials in Wisconsin and in conjunction with researchers in other states. In Wisconsin, we have observed that Endura applied at 8 oz at the R1 growth stage performs well. We have also observed that the fungicide Aproach applied at 9 fl oz at R1 and again at R3 also performs comparably to the Endura treatment. Other fungicide options also include Omega and Proline. You can view results of past fungicide evaluations for Wisconsin by CLICKING HERE.If you would like to run tailored estimations of return on investment for various fungicide programs, you can use another smartphone application called Sporebuster.
What is Sporebuster?
When a fungicide application is needed to control white mold in soybeans, Sporebuster can help determine a profitable program. You enter your expected soybean price, expected yield, and treatment cost. Sporebuster instantly compares ten different treatment plans at once to determine average net gain and breakeven probability of each. You can mark, save and share by email, the best plans for your farming operation.
The purpose of Sporebuster is to assist soybean farmers in making a fungicide program decision that is profitable for their operation. Sporebuster is meant to complement Sporecaster. Once Sporecaster recommends a fungicide application, Sporebuster can be used to determine a profitable program.
Information that drives Sporebuster is based on research from 2009-2016 from across the upper Midwestern US. Statistical models were developed based on these data that included white mold pressure and yield response from fungicide for 10 common fungicide programs. Details about the research behind Sporebuster can be found by CLICKING HERE to download a PDF version of a research update on the subject.
To watch an in-depth video on white mold management, CLICK HERE.
To find more information and download a fact sheet on white mold from the Crop Protection Network, CLICK HERE.
Scientific References
Willbur, J.F., Fall, M.L., Blackwell, T., Bloomingdale, C.A., Byrne, A.M., Chapman, S.A., Holtz, D., Isard, S.A., Magarey, R.D., McCaghey, M., Mueller, B.D., Russo, J.M., Schlegel, J., Young, M., Chilvers, M.I., Mueller, D.S., and Smith, D.L. Weather-based models for assessing the risk of Sclerotinia sclerotiorum apothecial presence in soybean (Glycine max) fields. Plant Disease. https://doi.org/10.1094/PDIS-04-17-0504-RE
Willbur, J.F.,Fall, M.L., Byrne, A.M., Chapman, S.A., McCaghey, M.M., Mueller, B.D., Schmidt, R., Chilvers, M.I., Mueller, D.S., Kabbage, M., Giesler, L.J., Conley, S.P., and Smith, D.L. Validating Sclerotinia sclerotiorumapothecial models to predict Sclerotinia stem rot in soybean (Glycine max) fields. Plant Disease. https://doi.org/10.1094/PDIS-02-18-0245-RE.
Fall, M., Willbur, J., Smith, D.L., Byrne, A., and Chilvers, M. 2018. Spatiotemporal distribution pattern of Sclerotinia sclerotiorum apothecia is modulated by canopy closure and soil temperature in an irrigated soybean field. Phytopathology. https://doi.org/10.1094/PDIS-11-17-1821-RE.
Willbur, J.F., Mitchell, P.D., Fall, M.L., Byrne, A.M., Chapman, S.A., Floyd, C.M., Bradley, C.A., Ames, K.A., Chilvers, M.I., Kleczewski, N.M., Malvick, D.K., Mueller, B.D., Mueller, D.S., Kabbage, M., Conley, S.P., and Smith, D.L. 2019. Meta-analytic and economic approaches for evaluation of pesticide impact on Sclerotinia stem rot control and soybean yield in the North Central U.S. Phytopathology. https://doi.org/10.1094/PHYTO-08-18-0289-R.
https://badgercropdoc.com/wp-content/uploads/sites/5/2018/08/IMG_37321-e1534709668147.jpg640480damonsmithhttp://badgercropdoc.com/wp-content/uploads/sites/5/2018/05/bcd-color-300x153.pngdamonsmith2020-07-03 20:27:142020-07-03 20:27:14Time to Think About White Mold Management in Soybeans in Wisconsin
Damon Smith, Extension Field Crops Pathologist, Department of Plant Pathology, University of Wisconsin-Madison
The Fungicide for Field Crops Information webpage on the Badger CropDoc website has now been updated! The update includes links to the latest fungicide efficacy tables from the Crop Protection Network as well as several updated fact sheets from UW Integrated Pest and Crop Management Program. Many fungicide application decisions will be made over the next month or so. Even if you are already familiar with fungicides and how they work, a little refresher might be helpful as you make product and application decisions. If you aren’t familiar with fungicides or how to use on field crops, this page covers the basics with lots of useful information.
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Updated for 2020! Fungicides are important tools for managing plant diseases in corn, soybean, and wheat. Unlike insecticides and herbicides that are used to kill insects and weeds, fungicides act as a barrier to protect healthy plant tissues from infection by fungi. But resistance to fungicides can become a real problem if not managed well. This 8 page publications has background information about resistance, reviews the relevant FRAC codes, management guidelines and has two significantly updated, handy tables that list fungicides by FRAC code and registered crop.
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Damon Smith, Extension Field Crops Pathologist, Department of Plant Pathology, University of Wisconsin-Madison
Roger Schmidt, Nutrient and Pest Management Program, University of Wisconsin-Madison
The Sporecaster smartphone app for predicting white mold epidemics in soybean has been updated for 2020. The new version is now available for download, or has been updated on your phone if you have automatic updates turned on. Updates include modifications internally and also a change on the user interface. These modifications were made based on feedback from users and our own internal testing over the winter of 2019/2020.
The most substantial changes include modifications to how we handle weather internally. The modifications were made to improve accuracy of the prediction when using GPS-referenced weather data. We also added the ability for the user to now adjust the action threshold for each individual location. This can be done based on your prior knowledge of severity at that location or the amount of risk you feel comfortable with. If you don’t know how severe past epidemics have been, then we suggest leaving the action threshold at its default.
Check back to badgercropdoc.com often during the season as we will also provide white mold updates on risk and commentary. Also follow us on Twitter @badgercropdoc for the latest in-season updates for field crops in Wisconsin. Don’t forget to subscribe to the Wisconsin Crop Manager for valuable crop updates.
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Each year the Wisconsin Field Crops Pathology Program conducts a wide array of fungicide tests on alfalfa, corn, soybeans, and wheat. These tests help inform researchers, practitioners, and farmers about the efficacy of certain fungicide products on specific diseases. The 2019 Wisconsin Field Crops Fungicide Test Summary is now available. These tests are by no means an exhaustive evaluation of all products available, but can be used to understand the general performance of a particular fungicide in a particular environment. Keep in mind that the best data to make an informed decision, come from multiple years and environments. To find fungicide performance data from Wisconsin in other years, visit the Wisconsin Fungicide Test Summariespage. You can also consult publication A3646 – Pest Management in Wisconsin Field Cropsto find information on products labeled for specific crops and efficacy ratings for particular products. Additional efficacy ratings for some fungicide products for corn foliar fungicides, soybean foliarand seed-applied fungicides, and wheat foliar fungicides can be found on the Crop Protection Network website.
Mention of specific products in these publications are for your convenience and do not represent an endorsement or criticism. Remember that this is by no means a complete test of all products available. You are responsible for using pesticides according to the manufacturers current label. Some products listed in the reports referenced above may not actually have an approved Wisconsin pesticide label. Be sure to check with your local extension office or agricultural chemical supplier to be sure the product you would like to use has an approved label. Follow all label instructions when using any pesticide. Remember the label is the law!
https://badgercropdoc.com/wp-content/uploads/sites/5/2020/01/2019-Fungicide-Summary.png24161864damonsmithhttp://badgercropdoc.com/wp-content/uploads/sites/5/2018/05/bcd-color-300x153.pngdamonsmith2020-01-10 20:52:152020-01-10 20:54:222019 Wisconsin Field Crops Pathology Fungicide Tests Summary Now Available
