Weed Watch: Lambsquarters



Lambsquarters is one of the first summer annuals to emerge in the spring, with approximately 25% of the plants emerging prior to any spring tillage or burndown herbicide application. Peak emergence is typically mid- to late-season, but lambsquarters can emerge throughout the growing season.1


Lambsquarters is one of the most prevalent weeds found in the U.S. Soybean Belt.1


Can reduce soybean yields up to 25% with less than one lambsquarters plant per foot of row.2


Young Plants

Cotyledons and seedling leaves have a mealy gray cast but turn green with age. Leaves alternate and are triangular, 1 � to 10 inches long.3


Mature Plants

Lambsquarters plants typically average around 3.5 feet but under the right conditions can grow to 6.5 feet.3,4


Seed Pain Points

One lambsquarters plant can produce up to 176,000 seeds, and one study found that 32% of seeds remained viable after 20 years.2

Because of its early emergence, lambsquarters can be one of the more difficult weeds to control in soybeans. It is critical to make sure weeds do not exceed the maximum height for postemergence weed control.2

Keys to Managing Lambsquarters1, 3, 4

  1. Rotate crops

    to diversify herbicide programs and weed control strategies.

  2. Start clean

    with a burndown herbicide or tillage.

  3. Apply a pre-emergence residual application,

    using a residual product within 2 weeks before planting or prior to crop emergence.

  4. Apply a postemergence application to target small weeds early,

    before weeds grow taller than 4 inches.

  5. Prevent Seed Production.

    If weeds escape, use tillage or physically remove them before plants produce seed.

A Closer Look At Postemergence Application

The key to controlling lambsquarters is all about the right timing and the right products. Apply a postemergence herbicide 20-30 days after planting, when lambsquarters is less than 4 inches tall and easier to control. Choose the right products with the right modes of action to give your crops the best defense against weeds:

XtendiMax® herbicide with VaporGrip® Technology 
  • XtendiMax® herbicide with VaporGrip® Technology, a restricted use pesticide, gives you up to 14 days of soil activity on certain small-seeded broadleaf weeds and is an effective tool to control emerged lambsquarters*
Warrant® Herbicide 
  • Warrant® Herbicide provides excellent levels of residual control on small-seeded broadleaf and grass weeds
Roundup PowerMAX® 
  • Roundup PowerMAX® herbicide controls emerged broadleaf weeds and grasses

With the right postemergence application, as part of a complete strategy, you can keep better control of weeds and help protect your crops to canopy.

Choose the System That Means Results

Choose the system that gives you advanced weed control and yield potential.

See System Overview