Agronomy Talk

Agronomy Update

Considerations for Wheat Fungicide Applications

Published on Thursday, April 28, 2016

Most of the wheat in our area was planted between October 1-10, with the majority planted by October 7. Along with timely planting, the warm fall promoted excellent fall growth and tillering for overwintering. I noticed a few challenges this spring where seeding depth was too shallow or significant residue created poor seed-to-soil contact. I continue to see that the best stands are the ones where residue has been evenly-distributed and lightly incorporated with a vertical tillage tool or disk prior to seeding. No-till also continues to work well where the seed is placed deep enough for good seed-to-soil contact.

Low temperatures the week of April 3 (22°F to 26°F) brought on concerns about freeze damage to the growing point. Most of the wheat during this time was just starting the jointing stage (Feekes 5 to 6). The wheat I have looked at from Decatur, IL to Ottawa, IL survived these cold weather events. The only noticeable damage in some areas has been leaf tip-burn, which is usually only cosmetic and very rarely translates to any negative yield. Inspections of the developing wheat head inside the stem, which is currently above node 2 or 3, appears healthy and is developing normally. (See Figure 1.)

Figure 1. A normal, healthy developing wheat grain head inside the stem
above node 3 documented on April 26 in east central Illinois

The majority of wheat in our area is now entering one of the most critical growth stages for managing leaf diseases. The flag leaf will be fully emerged in most fields by April 30. We often refer to this stage as Feekes 9. (See Figure 2.) Leaf diseases have been reported in southern Illinois and Kentucky, and with the latest storms and precipitation forecast for our area, assessing the need for a flag leaf fungicide now is important for protecting the genetic yield potential. No-till fields with residue currently appear to have more leaf disease than fields that were tilled prior to planting.

Figure 2. A wheat plant with the flag leaf (knife pointer) beginning to emerge.
This plant is currently at Feekes 8 and will likely be at Feekes 9 in a few days.

To protect wheat yield potential, it's important to keep the upper leaves of the plant disease-free and nutrient-rich. When scouting, I usually focus on diseases that are present on the flag leaf as well as two leaves below the flag leaf. The developing grain heads will remobilize the majority of stored nutrients from these upper leaves. If disease is currently present, or wet, humid conditions favor disease development, I normally recommend a fungicide at flag-leaf stage that contains multiple modes of action to provide a broad spectrum of control and combat disease resistance.

Midwestern University research currently indicates combination mode-of-action products such as Stratego® YLD, Quilt Xcel™, Priaxor®, and TwinLine® have been very effective to control and prevent many leaf diseases to help maintain optimum plant health. Single mode of action products, such as Headline® or Quadris® may also be very effective. Check individual labels for recommended application rates, required adjuvants, and diseases controlled. Please keep in mind that a fungicide applied at flag-leaf stage will not protect wheat against head scab (Fusarium head blight).

Once wheat reaches flag-leaf stage, it will take approximately 9 to 16 days to reach flowering, depending upon factors such as temperatures, fertility, and soil health. This stage is referred to as Feekes 10.5.1. (See Figure 3.) In our area, this growth stage is currently projected to occur as early as May 9 to 16. Proper timing of fungicide application during flowering is very critical.

Figure 3. Wheat at Feekes 10.5.1 (flowering). This is optimum timing to apply a
fungicide to protect against head scab (vomitoxin) with Caramba® or Prosaro®.

Wet, humid conditions during flowering will promote the development of head scab. Left uncontrolled, head scab can cause significant levels of vomitoxin, lower test weights, and lower yields. The triazole fungicides, Caramba or Prosaro, have been the best products to control head scab and can also help provide effective leaf disease protection. If your wheat plants are relatively disease-free at flag-leaf stage and you choose to only apply a product for head scab protection at flowering, you will get the benefit of leaf disease protection as well. It's important to note that a strobilurin-containing fungicide, such as many of those used at flag-leaf emergence, should NOT be used at flowering.

We will also be monitoring fields for the presence of armyworm larvae and the potential need for an insecticide mixed with the head scab fungicide. Please contact your local Beck's representative or field agronomist if you need additional help in scouting to determine how to help maximize your wheat yields and return on investment.

















Stratego® and Prosaro® are registered trademarks of Bayer. Quilt Xcel™ and Quadris® are trademarks of a Syngenta Group Company. Priaxor® Headline® Caramba® and TwinLine® are registered trademarks of BASF Corporation. 

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Chad Kalaher
Chad Kalaher>

Chad Kalaher

Beck’s Hybrids team sales agronomist for 22 counties in NE ¼ of IL and 7 counties in NW IN. Raised on grain and livestock farm in southern IL. B.S. Agronomy 1995 – University of Illinois, M.S. Weed Science 1997 – North Carolina State University. Previous positions in seed industry as researc

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Full biography

Beck’s Hybrids team sales agronomist for 22 counties in NE ¼ of IL and 7 counties in NW IN. Raised on grain and livestock farm in southern IL. B.S. Agronomy 1995 – University of Illinois, M.S. Weed Science 1997 – North Carolina State University. Previous positions in seed industry as research agronomist, district, and regional sales manager.


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