Cuscuta spp. Dodder

Tobacco may be parasitised by dodder (Cuscuta spp. Dodd) which gradually colonises the tobacco plant by its voluble stems (figure 1.) On the leafless stems, there are haustoria that enable dodder to absorb nutrients from its host without any photosynthetic activity. Dodder has also clusters of small flowers with different colours depending on the species (white, yellow, pink) (figure 2).

It produces countless seeds which remain viable in the soil for several years and are easily spread, similar to  the majority of soilborne pathogens, by water, or by soil particles.
 
To control dodder is particularly difficult. It requires additional measures such as those used to control soilborne pests: crop rotations with non-host plants crops, herbicides against pre-emergence. In France dodder may sporadically affect tobacco in traditional nurseries.