Analysis of Trade Flows of Ornamental Citrus Fruits and Other Rutaceae in the Mediterranean Basin and Potential for Xantomonas citri Introduction

Abstract

In this study, we built a basic scenario for risk assessment of the introduction of Xantomonas citri (X. citri), an agent of bacterial citrus canker, through international trade activities. According to the international phytosanitary authority European Food Safety Agency (EFSA), X. citri is currently included in the European Union A1 list (quarantine pests not present in the area) of the European and Mediterranean Plant Protection Organization (EPPO). Therefore, at the moment, to counter the spread of X. citri, some pest-specific phytosanitary requirements are foreseen in the case of citrus fruit commercial activities. One possible introduction route is through some ornamental Rutaceae, which are widely cultivated in Mediterranean countries, where they are economically important and have a social impact on the employees involved and the related industries. To assess the risk of introducing X. citri, we distinguished the import and export territories and the type of import material, and formulated a basic hypothesis linked to the positive correlation between commercial dependence on citrus imports from countries of the Mediterranean Basin and potential risk of invasion.

Risk management options to contrast the introduction of citrus fruit bacterial canker through ornamental Rutaceae in the Mediterranean Basin: An Italian case study

“…The main climatic data relating to average temperatures and average rainfall in the two areas (countries in which Xcc was detected and the main countries of the Mediterranean Basin) shown in Table 5, although synthetic, demonstrate the existence of ideal conditions for the development of the phytopathy in certain contexts that thus become susceptible to hosting the spread of the pathogen, favoured by high temperature and humidity [22].…”

“…Within this institutional scenario, an exploratory survey was conducted through a direct interview with professional nurserymen working in Sicily (Italy), at the center of the Mediterranean Basin [22], in order to acquire some elements of knowledge necessary for the design of a model of public intervention of prevention from the invasion of Xcc and some basic considerations have emerged:…”

“…Considering, on the one hand, the trade flow between areas at risk with Xc presence and areas in the Mediterranean Basin and, on the other hand, the interceptions made by EUROPHYT in European countries the probability of invasion is concrete and relevant, as shown in a recent analysis [22].…”

“…Among the plants concerned are "Limonia L.", "Microcitrus Swingle", "Murraya J. Koenig", "Severina", "Poncirus Raf. and their hybrids", etc., although they are hardly traded from risk areas [22]. The risk, however, is connected to the import of plant material destined for planting, as Xcc would find favorable environmental conditions for its development, but not from the import of fruit due to the low probability of transferring the bacterium to a suitable host with this medium.…”

“…The risk, however, is connected to the import of plant material destined for planting, as Xcc would find favorable environmental conditions for its development, but not from the import of fruit due to the low probability of transferring the bacterium to a suitable host with this medium. Recent studies have shown that the risk of potential invasion is significant in light of the intense commercial exchanges of plant material between some areas at risk because the pathogen is present in them, and the Mediterranean Basin [22]; the consequent potential damage is, therefore, significant [27].…”