An Integrated Weed Management Procedure for the Control of Dodder (Cuscuta indecora) in Alfalfa (Medicago sativa)

Abstract

Largeseed dodder is the most troublesome weed in alfalfa fields in the high desert of Southern California. Preemergence treatment with trifluralin controls dodder early in the season, but, as the season progresses, control declines. A method was needed to control attached dodder plants that escaped preemergence treatment. Flail mowing was compared to burning with a handheld propane-fueled weed burner. These methods were equally effective for controlling attached dodder, but flail mowing was more economical, and less injurious to alfalfa yield and stand density. Burning dodder patches at the end of the season reduced dodder seed viability by an average of 99%. Thus, we propose the use of a three tiered integrated approach consisting of PRE herbicide treatment followed by flail mowing in mid-season to control escaped dodder and burning at the end of the season to reduce dodder seed.