Soybean Rust Fungicide Best Practices

If soybean rust is present in your area, a preventative soybean fungicide application should be considered. Consult your local extension agent or crop advisor before applying a fungicide. The contact information for your local extension office can be obtained by consulting your telephone directory or the following website:
Please pay particular attention to the following points when considering a fungicide application:
  • There are products containing the active ingredients chlorothalonil and azoxystrobin that have full registrations (Section 3) for use on soybeans to control soybean rust. Syngenta Crop Protection markets these products, Bravo and Quadris, and makes their labels available at:
  • Some states have obtained Emergency Exemption (Section 18) labels for one or more other compounds.
    • A list of states that have obtained Section 18 labels for propiconazole (Tilt, Propimax, Bumper), myclobutanil (Laredo), and/or tebuconazole (Folicur) is available at:
    • These labels will not be in effect until your state pesticide regulatory agency, usually the state department of agriculture or department of environmental protection, determines that implementation of one or all of these Section 18s is appropriate.
    • For the Section 18 application to be lawful, you must be in possession of the label that describes controlling soybean rust with the product. This may include both the label that came with the product packaging and any applicable Section 18 label dealing specifically with this crop or disease.
    • Contact your local extension agent or crop advisor for more information regarding your soybean rust control options.
  • Follow the product's directions. Specific questions regarding application methods, timing, rates, etc., can be found on the product label. Your extension agent or crop advisor may provide further recommendations.
  • Proper post-emergence fungicide application may require different techniques than growers and custom applicators normally use for post-emergence herbicide applications. Some of the techniques generally recommended by fungicide labels include:
    • Complete spray coverage. While complete spray coverage is important for post-emergence herbicide applications, canopy penetration is critical for late season fungicide applications. The product's label recommendations and best management practices may require that you use,
      • Different nozzles
      • Different spray carrier volume
      • Different spray pressure
      In addition to local guidance, the following websites provide helpful fungicide application tips:

      University of Georgia: Soybean Pesticide Application Guidance

      TeeJet: Nozzle Selection Guide

    • Sequential applications. Temperature and precipitation conditions may dictate sequential fungicide applications. Refer to the product label and additional manufacturer recommendations for proper spray intervals.
  • When using any new pesticide formulation pay particular attention to:
    • The mixing instructions and spray tank agitation to avoid mixing problems or nozzle clogging; and The safety, environmental, and stewardship precautions outlined on the product label.
See also for more information and links