Scientific Opinion on the risk to plant health posed byBurkholderia caryophyllifor the EU territory with the identification and evaluation of risk reduction options

Abstract

The EFSA Panel on Plant Health conducted a pest risk assessment for Burkholderia caryophylli for the EU territory under the scenario of current EU legislation and identified and evaluated risk reduction options. B. caryophylli is absent from the EU territory. The host range of B. caryophylli includes the genus Dianthus and three other incidental, minor, hosts (statice, lisianthus and gypsophila). Seven entry pathways were identified, with carnation cuttings and cut flowers being the most frequently traded. All pathways were considered unlikely as the pathogen is rarely associated with the pathways at origin mostly because of the high phytosanitary quality of the plant propagation material. The establishment is unlikely because outdoors the environmental conditions are not favourable to the pathogen and alternative hosts are not present, whereas in protected crops the cultural practices are very effective to keep the crop free from this bacterium. Only very short‐distance spread within a crop is likely, and spread between different crops is unlikely. Risk reduction options addressing the sanitary status of the propagation material have the best effectiveness and feasibility. Effective control measures are based on healthy propagation materials (cuttings) and hygiene practices. With the existing certification scheme of carnation plant propagation material, the probability of spread through infected cuttings is largely reduced. The high effectiveness of current measures is ensured by the absence of B. caryophylli in the EU, as in recent decades no findings of B. caryophylli have been reported.B. caryophylli is reported to be present in some third countries in Asia, where it still causes high crop losses. If the current regulation were to be removed, major consequences or changes in the potential impact of B. caryophylli are expected if no voluntary certification scheme were applied, together with good sanitation standards, along the crop production chain.