Weed Watch: Marestail

 

Marestail

Marestail, also known as horseweed, can follow a winter or summer lifecycle and grows rapidly - and once this troublesome weed grows above 5 inches, it can be difficult to control with herbicides alone.1,2

 

This annual broadleaf weed is native to North America but can now be found worldwide.3

 

Failure to rein in its growth early can reduce yield by 40%.4

 

Young Plants

Up to 90% of fall emerged seedlings can survive winter and "bolt" in spring.5

 

Mature Plants

Leaves are entirely without petioles, and solid stems can reach 6 feet, while root systems consist of short taproots with fibrous secondary roots.6

 

Seed Pain Points

Seeds are numerous as each plant can produce up to 200,000 SEEDS, and 80% of these seeds can germinate immediately after falling from the mature plant.7

The evolution of herbicide-resistant and tough-to-control marestail is widespread. Keep weeds from affecting your bottom line by using well-designed best management practices, including a fall and spring burndown treatment, as well as residual herbicides to control weeds after planting. An integrated approach combining different sites and modes of action along with cultural practices can protect fields now and help prevent resistance in the future.

Keys to Managing Marestail

  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.