Diane's Plant of the Week: Dodder

Today I had a sample of one of my favorite and most interesting

Photo credit: Charlie Cambre

plants, a parasitic plant known as dodder. Often times people describe it as orange/yellow spaghetti growing in ditches or crop fields.  Dodder offers no benefit to its host, it strictly derives all nutrition from its victim to survive. 

Dodder does not have any leaves or, for that matter, any chlorophyll to produce its own food. It lives by attaching to a host plant and extracting the host plant’s carbohydrates. It does this by penetrating the host plant with small appendages called “haustoria.” Through the haustoria, dodder will extract the carbohydrates. It is not to the advantage for a parasite to kill its host, thus dodder generally will not kill its host, but if the infestation is severe enough, it may result in the death of the host plant.

Once thought to belong to the morning-glory family, it is now being placed in a family of its own, called cuscutacease. Dodders belong to the genus Cuscuta. The USDA plant data base lists approximately 47 species (http://plants.usda.gov).

Since dodders are annuals and are spread by seed, control

Photo credit: Charlie Cambre

with pre-emergents should work before it can attach to the host. Pre- applications of Kerb have provided good control of dodder in ornamentals and turf. Treflan and Prowl have also been reported to suppress dodder germination. However, Pre-applications often do not retain enough residual activity to provide control for the rest of the season.

Control of dodder with herbicides is dependent on the crop that you wish to control it in. Some herbicides may have an effect on the dodder, but may also either have an effect on the crop or may not be labeled for use in that crop. Always read and follow herbicide labels.

Excerpts taken from Dodder Publication from Purdue Plant Pest Diagnostic Laboratory.