FAQs

Why would I plan a fungicide application if I am not sure what disease pressure I’ll have - especially when commodity prices are low?

When it comes to addressing plant stress and disease, it’s important that you not take a “wait and see” approach, but instead consider planning ahead to protect your crop yield potential. If you take a “wait and see” approach and the disease takes a toll on the plant – that’s lost yield potential that can’t be recouped.

“To get high yields we’ve got to apply a fungicide in order to protect what potential we have.”  - Kyle Dixon, grower from Fulton, KY



Greg Kneubuhler, Agronomist with G+K Concepts Inc of Indiana suggests to combat tight times without sacrificing production. David Schrock, grower from Wakarusa, IN, explains how fungicide applications are a planned part of their crop plan.

What is Stratego® YLD fungicide?

Stratego YLD fungicide features the latest in triazole technology for corn and soybeans. Offering two modes of action, it provides both preventive and curative activities and systemic movement to provide broad-spectrum, long-lasting control of all important fungal diseases in corn and soybeans and higher yield potential.

Triazole Component
  • Unique redistribution activity, moving on the outside of the plant with free moisture, such as dew, down into the whorl, protecting new plant tissue as it grows.
  • Systemic movement inside the leaf translocates active ingredient to the leaf tips and edges.


Dr. Randy Myers, fungicide Product Development Manager for Bayer, explains how the triazole component (prothioconazole) in Stratego YLD is readily distributed on the outside surface of the plant, then slowly absorbed, moving systemically to new expanded leaves and tissue that would normally be unprotected.

Stratego YLD compared to other fungicides

Strobilurin Component
  • Rapid protection of the whole leaf through vapor phase distribution.
  • Penetration and translaminar distribution of the strobilurin complement the effect of the triazole.

Dr. Randy Myers, fungicide Product Development Manager for Bayer, explains how an audio radiograph was used to show how the unique property of Stratego YLD (vapor phase movement) redistributes trifloxystrobin (strobilurin component), even to untreated tissue.

Stratego YLD can be applied to wheat, soybeans, or to corn early season and/or at-tassel.

What diseases does Stratego YLD control?

With its powerful triazole component, Stratego YLD is effective on a broad range of diseases in corn and soybeans, including a higher degree of activity on anthracnose and rusts. Stratego YLD even stops strobilurin-resistant frogeye leaf spot (Cercospora sojina).

See Full List of Diseases >>

How does Stratego YLD combat disease resistance development?

Fungicides are vital to the future of agriculture, but their utility is at risk from pathogens developing resistance to specific modes of action. According to the Fungicide Resistance Action committee (FRAC), a specialist technical group of CropLife International, the best way to prevent and manage disease resistance is by using multiple modes of action in tankmixes and rotations—all at labeled rates. Stratego YLD contains two powerful broad-spectrum modes of action in one product, which helps fight the important fungal diseases in corn and soybeans, even strobilurin-resistant frogeye leaf spot.

What are the benefits of an Early Season Application (growth stages V4-V7) of Stratego YLD?

  • Healthier, stronger plants with increased standability and improved harvestability
  • Improved Strength - Fosters stronger, healthier plants that are better able to stave off environmental stresses
  • Low application rate of only 2 oz/A
  • Higher ROI: Lower application rate at early season timing + an average bushel increase of 7 bu/A = higher ROI when applied V4-V7
  • Tankmix compatible with postemergence herbicides: Saves on additional application cost when tankmixed with planned herbicide application

Why do the use rates differ between early season applications of Stratego YLD and tassel applications?

The recommended range of use rates for tassel applications of Stratego YLD is 4 to 5 fl oz/A. The range for early season applications (growth stages V4 to V7) is 2 to 5 fl oz/A.

Four to 5 ounces of Stratego YLD applied between growth stages VT to R2 has proven to be quite effective in controlling important diseases and improving plant health. These plants are very tall with large biomasses that need to be protected. By contrast, plants between growth stages V4 and V7 are much smaller and have less leaf area to protect. The leaves are arranged in such a fashion as to collect the most sunlight, so there is limited shading of lower leaves by upper leaves. Coverage is much easier to attain on the smaller, more exposed plants.

How can an early season rate of 2 fl oz/A of Stratego YLD be an effective rate?

The performance and residual activity of a fungicide are determined by the concentration of active ingredient per unit of plant surface area. Because less leaf area is present at early season than after tassel emergence, the active ingredient sprayed per acre is less diluted. Studies have shown that the concentration of active ingredient per unit of leaf area on the fifth leaf treated with 2 fl oz/A of Stratego YLD at V5 is more than 40% higher than on the ear leaf treated with 4 fl oz/A of Stratego YLD at VT.

There is a minimum concentration of active ingredient on the leaf’s surface that effectively controls fungal infections. Once that concentration is reached, the benefit of higher concentrations is longer residual activity. After application, the active ingredient begins to degrade or be inactivated. The higher the initial application rate, the longer it takes for the concentration to fall below the effective level. This time denotes the length of the residual control.

How is protecting a small corn plant different from protecting a plant after tassel emergence?

As the corn plant develops, the lower leaves are sloughed. The stalk expands, splitting the leaf sheaths of the early leaves, and brace roots rip through the sheaths of leaves growing from earlier nodes. These damaged leaves wilt and senesce. Because the first five or six leaves are not attached to the plant for very long after the early season spray, the residual activity provided by the fungicide does not need to be overly long.

Since the concentration of active ingredient on the fifth leaf treated early season with 2 fl oz/A of Stratego YLD is 40% higher than on the ear leaf of a plant treated with 4 fl oz/A of Stratego YLD at tassel emergence, the residual activity of the size-appropriate rate protecting the young leaves will extend well beyond the life of the leaf on the plant.

If applying 2 fl oz/A of Stratego YLD early season provides ample protection for expanded leaves, why does the use rate range from 2 fl oz/A to 5 fl oz/A?

During the early application window from growth stages V4 to V7, the expanded leaves are spatially arranged to capture the most sunlight, which also orients them to intercept the most spray solution from a fungicide application. Two ounces of Stratego YLD per acre will coat and protect the expanded leaves with active ingredient.

However, as the plant grows to the later stages of this application window, V6 and V7, three or more leaves will be developing in the whorl. These leaves will typically be on the plant much longer than the younger leaves, and thus would benefit from longer residual activity of the fungicide provided by the 4 fl oz/A rate. Additionally, the vertical orientation of these leaves makes it more difficult to deposit the desired concentration on the surfaces. Greater protection of these developing leaves can be attained with the higher rates, such as 4 fl oz/A of Stratego YLD.

What makes Stratego YLD the best fungicide choice for early season sprays on corn?

Stratego YLD has two active ingredients; each has a broad spectrum of activity on a broad range of fungal pathogens. Additionally, each chemistry has redistribution properties that are key to better protection of a plant that is rapidly expanding.

Virtually all fungicide molecules are active on the plant surfaces that come in contact with the spray solution. If there is systemic movement, the molecules move into the leaves and are carried with water flow through the xylem vessels to the edges and tips of the leaves. However, there is essentially no downward movement. Corn leaves expand from the leaf base, so new tissue coming out of the whorl is left unprotected by most products.

The unique strobilurin chemistry in Stratego YLD quickly binds to the waxy surfaces of the corn plant. This chemistry also has a vapor phase that allows for short distance movement to neighboring surfaces. As new leaf tissue forms, the strobilurin in the vapor phase can move to the expanding tissue and bind to new surfaces.

The triazole chemistry in Stratego YLD, prothioconazole, is the newest triazole on the market and also has unique redistribution properties. As with other typical triazole molecules, some prothioconazole enters the plant, attacks existing fungal infections and moves in the xylem to the edges of the intercepting leaf. What differentiates prothioconazole is how its molecules on the leaf surface are redistributed. While adhering to the leaf, it can move downward with surface moisture on the leaf. The surface moisture, such as dew, serves as a vehicle for prothioconazole redistribution. The orientation of young corn leaves further serves as a funnel, carrying prothioconazole deeper into the whorl where new tissue is emerging. Prothioconazole can enter the new leaves and be transported upward in the xylem to expand the protection of the plant.

This combination of active ingredients provides unsurpassed protection of young, quickly developing corn plants.

How does Stratego YLD help harvestability in corn?

Stratego YLD fights disease on both leaves and stalks, which keeps plants standing healthier, longer which results in improved harvestability. These stronger, healthier plants are less prone to lodging; harvesting lodged corn forces you to reduce speed to minimize yield losses, but slower speeds increase harvest expenses. By improving standability, Stratego YLD reduced lodging and improved productivity, ultimately saving you time and helping you retain more profit.

Can Stratego YLD be tankmixed with an insecticide on soybeans?

One tankmix of Stratego YLD fungicide and Leverage® 360 insecticide controls insects and diseases, while enhancing yield potential, all in a single pass. Put these two proven, yield-enhancing performers to work for your soybeans.

Stratego YLD is also compatible with most other crop protection products and adjuvants. Read Label for Full List.

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