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Take These Three Steps to Fight Frogeye Leaf Spot

June 11, 2021
frogeye leaf spot on soybean leaf

Frogeye leaf spot in soybeans

Summer has arrived, and one disease in particular should come to mind. Causing yield loss across the South, frogeye leaf spot is a top concern for soybean growers every year. Researchers at the Alabama Cooperative Extension System say national yield losses due to frogeye leaf spot have been estimated as high as 30%. And if this disease wasn’t troublesome enough, frogeye leaf spot has developed resistance to the strobilurin mode of action, with confirmed cases of resistance in 18 states.

To combat this disease and protect yield potential this season, we recommend following these 3 steps:

Step 1: Understand Your Fields’ Risk for Disease

With projected high market prices, many growers are planting continuous soybeans, but this also creates a higher risk for disease development. If you planted continuous soybeans or had short rotations between your soybeans, be on high alert for signs of frogeye leaf spot. You should also be watchful if you planted a susceptible variety or practice no-till in your fields.

Step 2: Scout Often

Frogeye leaf spot thrives in warm, humid weather, so scout often as we enter the summer season. When scouting, check the upper leaf surfaces for small dark spots. As the disease develops, these spots will grow larger and lighten in color. You also may see lesions appear on pods and stems later in the season, although spotting this symptom is less likely.

Step 3: Apply a Preventive Fungicide

Frogeye leaf spot has developed an increasing resistance to strobilurin, or QoI, fungicides. This means many older formulations have reduced efficacy against strobilurin-resistant frogeye leaf spot. Be sure to choose a fungicide with multiple modes of action and apply at R3 – R5 for the most efficient protection.

To battle tough diseases like frogeye leaf spot, we recommend an application of Miravis® Top fungicide. Miravis Top is custom-built with 2 modes of action – including Adepidyn® technology – with proven activity against strobilurin-resistant pathogens, delivering superior disease control. Plus, it provides added plant-health benefits that help maximize yield potential.

To learn more about Miravis Top and see trials from your region, visit our new Miravis brands performance hub.

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