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Solo-strobis slipping for soybean frogeye leaf spot control

June 21, 2016

frogeye leaf spot

With 2016 soybean planting all but wrapped up, growers should begin to scout fields for pest pressure. Heavy disease pressure in 2015 followed by a mild winter can bring diseases like frogeye leaf spot into fields earlier this year. And, with the growing frequency of strobilurin-resistance, researchers recommend using fungicides with multiple modes of action to effectively manage frogeye leaf spot.


  • Appears as yellow-grey lesions with reddish-brown borders
  • Can result in premature defoliation, seed infestation and/or yield loss by as much as 30 percent

Best management practices:

  • Scout for the disease as plants approach reproduction
  • Apply a fungicide at the R3-R5 growth stage for the most consistent yield protection (under conditions of high disease pressure), according to The University of Tennessee
  • Use a fungicide with more than one mode of action to prevent or delay resistance

Multiple MOAs offer superior control

Quadris Top® SBX fungicide contains two active ingredients, azoxystrobin and difenoconazole, for superior disease control and resistance management. Independent trials from the Purdue University Extension showed that these two active ingredients offered the best control of frogeye leaf spot compared to the chemistries used by competitors.  The pictures below from the 2012 fungicide efficacy trials in Valley View, AR tell the story.


While some fields may have dodged frogeye leaf spot in the past, they are still susceptible to the important disease and its resistant strains. Staying vigilant and properly treating frogeye leaf spot with multiple modes of action can help save yield and manage resistance.

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Product performance assumes disease presence.

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