Act Soon To Manage Invasive Marestail In Pasture

By: Gary Stone

Early Detection and Rapid Response is a concept to identify potential invasive species before or just as the establishment of the invasive species is taking place. An integrated pest management plan can be developed to manage, contain and eradicate the invasive species before it can spread further, avoiding costly, long-term control efforts.

A native species that has become a major problem in the Nebraska Panhandle and Sandhills rangeland is marestail or horseweed.

With the advent of no-till farming and repeated use of glyphosate products, marestail has become glyphosate-resistant and a major weed problem in corn and soybean-producing areas. Marestail also is resistant to some ALS inhibitor (amino acid synthase) and PPO (cell membrane disruption) herbicides.

Some have speculated that marestail’s increase in pastures and rangeland is because of recent cool, wet springs, causing an increase in seed germination. While these plants may not be glyphosate-resistant, ranchers are concerned they are losing valuable grazing potential because of this plant.