PRA prepared by the Secretariat. A document with extract of reports were the PRA was presented is also available.

Overall, the replies of this pest risk assessment seem to be “not very likely”. Striga spp. are not very likely to be introduced by existing pathways, not very likely to establish in most of the EPPO region, and not very likely to be a serious problem in the parts where they might establish. Despite fairly free movement of seeds and other pathway commodities into most of the EPPO region, no Striga sp. has ever been reported. The most important hosts (maize and sorghum) are not grown on their largest scale in the EPPO region in the southeast where Striga could most easily establish. As obligate parasites, Striga spp. need hosts on which to persist, and are not particularly favoured by the conditions of Euromediterranean agriculture. Provided seed stocks can be kept free, there is little risk of widespread Striga infestation. Nevertheless, it could be concluded that S. lutea, with its relatively wide geographical distribution and some history of spread, and its host preferences, stands out as the species which presents most risk for the EPPO region. It can also be added that EPPO countries have in general taken measures to avoid introduction of pests with soil from the tropical areas where Striga spp. mostly occur. The exclusion of semi-parasitic weeds such as Striga continues to be one of the justifications for such general measures applied to the import of soil.