By Scout Nelson
Field pennycress, a weed known for its high frost tolerance and early germination, is being found more frequently in pastures this year, especially in Western South Dakota. This cool-season plant may look harmless, but in larger quantities, it can be toxic to livestock. It grows quickly and competes with other forages by sprouting in the fall and early spring.
When pastures contain high amounts of field pennycress, farmers should carefully observe the health of their animals. While cattle are usually less affected, horses can react more strongly if they eat too much of it. Additionally, consuming large amounts may change the taste of meat or milk, making it less appealing.
Managing field pennycress can be challenging. Mowing does not stop its growth, as it quickly regrows and branches again. A good strategy is to plant dense, competitive grasses like smooth brome or crested wheatgrass. These grasses help prevent pennycress from taking over the field. In areas where field pennycress is already growing, farmers can use electric or virtual fencing to keep animals away, allowing other grasses to grow and take control of the space.
Hay containing high levels of field pennycress should be avoided. If such hay is already baled or bought, it should be fed in controlled areas where the weed can later be sprayed, tilled, or managed. This helps prevent a large weed seed bank from forming.
To deal with serious cases of pennycress, farmers can use tools like rangeland assessments and create a plan for grazing and weed control. In cropland or cultivated pastures, cover crops or tilling can help reduce its seeds and future growth.
Photo Credit: gettyimages-imaginegolf
Categories: South Dakota, Crops, Livestock