Move Quickly to Control Frogeye Leaf Spot

soybean field

If you grow soybeans in the South, you know the question isn’t whether frogeye leaf spot will show up. The question is when.

Though you can’t answer this question at the beginning of the season, watching the weather can give you a pretty good idea of when that timing is upon your field. When that happens, grab the spray rig. Bugwood.org explains why: “Under the temperature range of 77-86˚F (25-30˚C) and in the presence of water, the fungal conidia can germinate within an hour upon arrival on healthy soybean tissue.”

An hour. Once the frogeye leaf spot fungus lands on a leaf, infection starts. If the crop is full of young leaves, the temperature is in that sweet spot for disease, and relative humidity is over 90 percent, the infection spreads rapidly.

That’s why Bayer Senior Technical Service Representative Malone Rosemond recommends using prevailing conditions and crop stage to decide when to treat. Don’t wait until you see signs of disease. The most vulnerable period for soybean crops in the south is between R1 and R3.

“It’s best to spray as conditions are conducive for disease,” Rosemond said. “Start those applications at flowering, or R2, and then repeat on a 14-day schedule if the conditions are still there.”

In untreated fields, loss can be significant.

Double Up Your AIs to Manage Resistance

In most years, many fields will only need one treatment application. That said, scouting is essential to monitor for disease. Since strobilurin-resistant frogeye leaf spot is well established in the south, Rosemond recommends using a product with two active ingredients. Stratego® YLD is one of those products.

“With Stratego YLD, there are two active ingredients that provide both curative as well as protective activity. And it will control resistant frogeye,” Rosemond said.

Those are just the headlines for Stratego YLD. Stratego YLD also offers:

  • Increased Yield. Research shows soybean fields treated with Stratego YLD bring an average yield of 3-4 bu/A higher than untreated fields.  
  • Tankmix Compatibility. Stratego YLD is tankmix compatible with most crop protection products, including herbicides, insecticides and adjuvants.
  • Low-Use Rate. Protect soybean plants from disease with rates as low as 4 fl oz/A for traditional applications
  • Higher Profit Opportunity. Decreased disease and higher yield potential ultimately lead to higher profit opportunity.

Be ready to protect your soybean crop when disease threatens. Contact your Bayer representative for more information.



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