Controlling marestail or pigweeds post-emergence in soybeans is always easier when the weeds are small – less than 2 inches tall is preferable for good control. This article outlines some suggestions for controlling these weeds post-emergence in soybeans.
Controlling marestail in soybeans continues to be a big challenge for Kansas no-till producers. Application timing and weed size are critical factors for successful control of this weed that germinates in the fall or early spring.
Timely herbicide applications are key for post-emergence control of marestail. Management is complicated due to some populations in Kansas with resistance to glyphosate and ALS-inhibiting herbicides. However, there are some options for control of large marestail.
With row crop harvest well underway, it is time to start planning fall herbicide applications. Herbicide applications in late October through November can improve control of difficult winter annual weeds.