Unfortunately, these herbicides have a limited longevity, making repeated treatments necessary. Herbicides applied after attachment have limited success. General contact herbicides can be effective, but also will injure the forage plants. Paraquat is a herbicide in this classification. Herbicide selectivity is difficult to accomplish at this stage.
Selective herbicides can control the stems but often the haustoria escapes.
Research has shown limited success but no practical recommendation is presently available. Studies in California in the late 1980s showed trifluralin, pendimethalin and prodiamine to be effective soil-applied herbicides for dodder control. However, dodder control diminished throughout the growing season. A high, early season application rate or a split application improved season-long control. Dodder plants that escaped the treatments were controlled by burning or flail mowing.