Pest risk assessment made by France on Citrus exocortis viroid (CEVd) considered by France as harmful in French overseas department of Réunion - Scientific Opinion of the Panel on Plant Health

Following a request from the European Commission, the Panel on Plant Health was asked to deliver a scientific opinion on 30 pest risk assessments made by France on organisms, which are considered by France as harmful in four French overseas departments, i.e. Guadeloupe, French Guiana, Martinique and Réunion. In particular, the Panel was asked whether these organisms can be considered as harmful organisms for the endangered area of the above departments, in the meaning of the definition mentioned in Article 2.1.(e) of Directive 2000/29/EC and thus potentially eligible for addition to the list of harmful organisms in Directive 2000/29/EC.This document presents the opinion of the Panel on Plant Health on the full[1] pest risk assessment conducted by France on Citrus exocortis viroid (CEVd) with Réunion considered as endangered area.CEVd isa well-characterised viroid of the family Pospiviroidae, which infects citrus, grapevines and several herbaceous species of economic importance belonging to different families. CEVd is considered as widespread all over the citrus-growing areas of the world.The Panel examined in detail the risk assessment provided, and considered the accuracy and quality of the information provided and methods applied for pest risk assessment purposes. The review was based on the principles and terminology of the International Standard on Phytosanitary Measures ISPM No. 11[2] [Pest risk analysis for quarantine pests including analysis of environmental risks and living modified organisms (2004)] and the terminology of ISPM No. 5 [Glossary of Phytosanitary Terms (2007)] by the International Plant Protection Convention (FAO, 2007).The French document is unclear in its conclusion, stating that CEVd could feature as a pest in Réunion, yet acknowledging that CEVd is already present in the PRA area[3]. The document suggests that although preventative measures are limiting its further spread, its impact is minimal. The Panel found that many other statements, for example, those relating to economic impact, appear contradictory to the ratings given, or to statements made earlier in the assessment. In addition, many statements are neither substantiated by references nor supported by verifiable data, for example, relating to the extent of the occurrence of CEVd, the control measures undertaken and the impact of citrus exocortis disease in the PRA area.CEVd is present in citrus producing countries worldwide and it can be spread by graft-propagation of infected planting material. Therefore, the Panel agrees that the introduction of infected propagation material is the most important entry pathway. The volume of imported material into Réunion, however, is acknowledged in the French assessment to be low, due to the small area of citrus under production.CEVd is a well-characterised viroid in terms of its molecular and biological properties and suitable methods are available to identify and detect it in plant material. As a result, the Panel considers that viroid-indexing can reduce the probability of entry via propagation material to a negligible level. The probability of entry was rated as moderate in the French document. However, in the absence of viroid-indexing, the probability of entry is considered by the Panel to be moderate to high.The probability of establishment was rated as moderate in the French document but the Panel considers this to be high, as CEVd would be established following the planting of any infected material. CEVd is also acknowledged as present in old plantings in the PRA area where the original plants have not been subjected to viroid-testing procedures. The Panel, however, considers these represent a low risk in terms of being a source of contamination of newly established CEVd-free orchards. Although CEVd can be spread by vegetative propagation of infected material, efficiency of mechanical transmission under field conditions is low and transmission can be avoided by disinfecting cutting and pruning tools.CEVd is not spread by seed-transmission and has no known natural vectors. As a consequence, the probability of spread is considered by the Panel to be low.CEVd is a pathogenic agent for citrus grown on sensitive rootstocks, causing stunting and reduced yield. The Panel confirmed that sensitive rootstocks such as Carrizo citrange are used for new plantings in Réunion.Existing risk management measures prevent the importation of citrus planting material from Third (non-EU) countries (Annex III A of Directive 2000/29/EC). Virus indexing procedures can be applied as part of existing certification schemes for citrus propagation material in the EU. Furthermore, in the absence of virus indexing, the Panel considers the impact of CEVd to be limited, due to the absence of a natural vector, which limits the potential for further dissemination of the viroid.Therefore, the Panel concludes that CEVd is not appropriate for evaluation of further risk management measures and thus is not considered by the Panel to be eligible for addition to the list of harmful organisms in Directive 2000/29/EC