This directive has been revised from the original version in order to update the phytosanitary requirements under Section VII.2.2.2.
Parasitic plants obtain their nutritional requirements directly from their hosts.
In this way, they are different from weeds, which compete for space, nutrients, light, etc., but do not feed off other plants. They have the potential to cause serious economic damage to crops in Canada and they are not easily amenable to control with chemical pesticides as are other plant pests, including weeds. It is difficult to distinguish propagative materials, especially seed, of the different species within these named genera of plant parasites. Therefore all propagative material of Cuscuta , Striga , and Orobanche spp. are regulated at the genus level i.e. regardless of the species. Niger seed and buckwheat hulls may originate from areas where these pests are known to occur, and are known carriers of these pests.