Scientific Opinion on the risk to plant health of Xanthomonas citri pv. citri and Xanthomonas citri pv. aurantifolii for the EU territory

Baker , Richard [Oxford University] Bragard, Claude [UCL] Candresse, Thierry [INRA] Gilioli, Gianni [University of Parma] Grégoire, Jean-Claude [UCL] Holb, Imre [Institute of Plant Protection, Budapest, HU] Jeger, Michael John [Imperial College London] Karadjova, Olia Evtimova [Institute of Soil Science, Agrotechnologies and Plant Protection, Sofia, Bulgaria] Magnusson, Sven Christer [Bioforsk Plant Health, Norwegian Institute for Agricultural and Environmental Reseach] Makowski, David [INRA] Manceau, Charles [Agence nationale de la sécurité sanitaire de l'alimentation, de l'environnement et du travail] Navajas, Maria [INRA] Rafoss, Trond [Farsund mucicipality] Rossi, Vittorio [Universita cattolica del Sacro Cuore, Piacenza, Italy] Schans, Jan [Netherlands food and consumer product safety authority] Schrader, Gritta [Julius Kuehn-Institut (JKI)] Urek, Gregor [Agricultural Institute of Slovenia] van Lenteren, Johan Coert [Wageningen University] Vloutoglou, Irene [Benaki Phytopathological Institute] Winter, Stephan Stephan [Leibniz Institut DSMZ] van der Werf, Wopke [Wageningen University] et al.[show all]

The Panel conducted a pest risk assessment for Xanthomonas campestris (all strains pathogenic to Citrus) for the EU territory and an assessment of the effectiveness of present EU requirements against Xanthomonas strains pathogenic to citrus. The risk assessment was conducted under the scenario of absence of the current specific EU plant health legislation and the assumption that citrus-exporting countries apply measures to reduce yield and quality losses. Risk reduction options were systematically identified and evaluated. The strains of X. campestris pathogenic to citrus have been reclassified as four distinct infraspecific taxa within two species: X. citri and X. alfalfae. Only two pathovars (X. citri pv. citri and X. citri pv. aurantifolii) are responsible for the citrus bacterial canker thatpresents a major risk for the citrus industry in the EU. Seven entry pathways have been identified and evaluated. The likelihood of entry was rated unlikely for fruit, very likely for fruit plants for planting, moderately likely for ornamental plants for planting and unlikely for leaves and twigs. The uncertainty of probability of entry was rated as high. The probability of establishment was rated as moderately likely to likely with a medium uncertainty because host plants are widely present in EU areas where environmental conditions are suitable. Once established, spread would be likely with a low uncertainty. The impact of the disease, even if control measures are applied, was rated as moderate to major with a medium uncertainty. The disease would cause yield losses in areas where citrus is the main crop, increase the need for control measures and create environmental problems.The combined EU regulations have been shown to be effective in preventing the introduction of X. citri pv. citri or X. citri pv. aurantifolii in the EU, as no outbreaks of citrus canker in the EU territory have been reported.