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Top 5 Reasons to Manage Your Weed Seed Bank

March 2, 2020
This agronomic image shows velvetleaf weeds


In 2019, wet weather conditions delayed and prevented planting as well as preemergence herbicide applications, setting us up for a nasty weed situation in 2020. An elevated level of weed seeds waiting to germinate means vigilant management is key to a successful season.

Here are 5 reasons to prioritize a strong ag herbicide program and prevent weeds from going to seed:

  1. Weeds produce an extraordinary amount of seeds. For example, a single waterhemp plant can produce up to one million seeds. That means one waterhemp escape in 2020 can create up to potentially one million new waterhemp plants to fight in 2021.
  2. Weed seeds are quite hardy. They can survive in the soil for varying lengths, with some lasting multiple generations. Palmer amaranth can remain dormant up to 6 years, while velvetleaf can remain viable up to 60 years.
  3. Weeds impact yields by altering a corn plant’s behavior. Iowa State University found weeds reflect sunlight against crops, triggering a natural response in corn that reduces yield potential. Another study found corn uses its energy to grow taller than weeds to reach that sunlight instead of developing strong root systems – a crucial part of early-season development that has implications through harvest.
  4. Weeds impact yields by competing with crops for valuable water, nutrients and sunlight. Did you know a single giant ragweed consumes nearly 3x as much water to produce 1 lb. of dry matter as a corn plant1, meaning even small populations are significant yield robbers? In soybeans, the trifecta is so substantial that weeds can reduce yield by 1% per day if left uncontrolled after the V2 to V3 stage.2
  5. As if lower yields and extra cost spent on herbicides to clean up escapes weren’t enough, weeds can continue to have financial implications after harvest. If weed seed is hauled to the elevator along with a grower’s hard-earned crop, their grain’s price point could face dockage.

As you can see, what may appear to be just 1 innocent weed can quickly multiply and wreak havoc on corn and soybean yields. That’s why it’s important to plan ahead with a comprehensive control strategy, including herbicides as well as sound agronomic principles such as tillage.

There are several types of herbicides we recommend. With fast-acting results in as little as 48 hours, Gramoxone® SL 3.0 herbicide delivers convenient, flexible and dependable burndown of emerged grass and broadleaf weeds in corn and soybeans.

If corn hasn’t emerged and weeds are present at application, tank mix Gramoxone SL 3.0 with Acuron® corn herbicide in reduced or no-till systems for additional control. As an added bonus to weed control, trials show Acuron delivers 5-15 more bushels an acre than any other corn herbicide*, and with the current commodity prices, every bushel counts. Calculate the potential extra revenue you could be making with Acuron.

In soybeans, we recommend a preemergence application of Boundary® 6.5 EC, BroadAxe® XC or Prefix® herbicide followed by Tavium® Plus VaporGrip® Technology, the market’s first premix residual dicamba herbicide. Tavium controls a broad spectrum of both preemergent and post-emergent weeds through contact and residual control for up to 3 weeks longer than dicamba alone.

Weed seed banks have the potential to be devastating, but with the right strategy in place, growers can rest easy knowing their fields are protected. See how weed resistance has spread across the U.S. in the last 50 years, and learn more about how to keep tough weeds from jeopardizing your profits.

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2Hartzler, R. 2003. Is your weed management program reducing your economic return? Iowa State University.

*When applied preemergence and at full label rates. Yield advantage range based on 2016 Syngenta and University trials comparing Acuron to Corvus®, Resicore®, SureStart® II and Verdict®. For more information on Acuron versus an individual product, ask your Syngenta representative.