Scientific Opinion on the risk to plant health posed by Puccinia horiana Hennings for the EU territory, with the identification and evaluation of risk reduction options

The Panel on Plant Health conducted a pest risk assessment for Puccinia horiana Hennings (the causal agent of chrysanthemum white rust) for the EU territory, identified risk management options and evaluated their effectiveness. The assessment was conducted taking into account current EU legislation. The Panel also provided an opinion on the effectiveness of the present EU requirements against this organism, listed in Council Directive 2000/29/EC. Two major pathways for entry were identified: plant material of susceptible hosts for propagation purposes and cut flowers of Chrysanthemum × morifolium. The probability of further entry of the pest was considered unlikely, as the existing certification schemes for propagation material should reduce the risk of importing infected cuttings. For cut flowers, pest transfer to susceptible hosts is associated with the potentially incorrect disposal of cut flower waste within the vicinity of places of production, which is considered a rare event. The probability of establishment and further spread were both considered very likely. The current overall impact in the risk assessment area was considered minor, with medium uncertainty, mainly because standard protective actions are taken in most EU production areas. Risk reduction options to reduce the probability of entry and spread and mitigate the impact were analysed. Council Directive 2000/29/EC addresses mainly the sanitary status of the propagation material. The Directive cannot prevent the entry, establishment and spread, or mitigate the impact, of the pathogen. Were the current regulation to be removed, the frequency of introduction would probably increase. This poses a risk because, although the pest is widespread in the risk assessment area, not all Member States are infested and not all pest pathotypes are present. If a statutory certification system, with associated import requirements for propagation material of host plants, were introduced, this would include practically all prescriptions of the present regulation.