Much of the state is still wet and waiting for dry conditions to resume field activities. Scouting for weeds now can help spot any issues and plan for spring burndown programs. By late spring, it’s not uncommon to see many fields covered in yellow flowers of an increasingly common winter annual weed. This weed can appear in winter wheat and ahead of corn and soybean production but can be a deadly concern in managed systems where livestock are fed. Scouting for cressleaf groundsel, also called butterweed, at this time can prevent unexpected issues for livestock production later in the season.
Depending on the level of infestation cressleaf groundsel can be toxic to livestock fed with hay or grazing pastures, causing liver disease and losses on animal performance. Although toxic properties are higher in more mature plants, the best time to control this weed is when plants are small. Waiting until plants have bolted and flowers are visible reduces control options and increases risk of losing the first hay cutting. In the rosette stage, cressleaf groundsel can appear similar to other common winter annual weeds in Ohio, but can be differentiated by leaves arranged opposite to each other and with round lobed margins. Resources for cressleaf groundsel identification and control include videos, fact sheets, PowerPoints, and a control guide. Previous C.O.R.N. newsletters listed below cover the biology, toxicity, and control of this weed.
Spring control of winter weeds in hay and pasture
Scout now for cressleaf groundsel in hayfields, or pay the price in May