Marestail (Erigeron canadensis), also called horseweed, is a troublesome weed in several cropping systems in Kansas and beyond. Marestail is most problematic in reduced or no-tilled fields. Learn how to identify and control this pest in this latest World of Weeds article.
Giant ragweed, also called horseweed, often comes to mind as a contributor to seasonal allergies in the fall. However, emergence of this weed begins in early spring, making it a timely topic for the March World of Weeds article.
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. Marestail that does survive over winter is often robust and can be difficult to control with herbicides, especially later in the spring.
Marestail, or horseweed, is a challenging weed to manage in no-till or minimum-till systems. Acceptable control of fall-emerged marestail with herbicide applications at planting will be unlikely because the marestail are generally too large, but control can be achieved with both fall and early spring herbicide applications. Other control options include tillage and cover crops.