The European system of plant passports is not enough to contain phytosanitary risks like Xylella fastidiosa, says Martin Ward, Director General of the European and Mediterranean Plant Protection Organization (EPPO).
First of all: what does EPPO do?
„We make recommendations on phytosanitary issues, it is technical advice that we give to the countries that are members of EPPO, and also to the European Commission in Brussels. Our work overlaps to some extent with the work of EFSA, the European food safety authority. For example, the EFSA carried out the risk analysis of Xylella fastidiosa.
Our work differs from that of the Standing Phytosanitary Committee in Brussels, which includes representatives of all EU phytosanitary services – like the NVWA from the Netherlands. They regulate rules, we provide technical advice.”
On what are EPPO recommendations based?
„On scientific research, not only in the EPPO region, but we consult experts from all over the world. That depends on the issue. For example, if an organism has been around for a long time in another part of the world, but not yet in our region and it will threaten us: then we will get information from that region.”
Apart from Xylella, which organisms are also main topics for EPPO?
„Xylella is indeed still one of the most important issues we are struggling with. Because the disease is now present in the EU, but to what extent will it spread? Other key issues are for example rose rosette disease, caused by a virus and spread by a mite.”
When you were UK chief plant health officer, in 2013 you set up an extensive risk register with hundreds of organisms in it. Does every EPPO country now work on such a register?
„Not yet, and from EPPO we follow the developments in that area. France, Finland and other countries, for example, already have interesting approaches to prioritising risks. We encourage countries to exchange information with each other. There are differences in climate zones, but I do not think it would be useful if every country carries out a risk analysis of the same organism, while there is a lot of information elsewhere.
There is always an uncertainty about an organism. The extent of distribution in an area may not always be clear.”
How does EPPO synchronize information from different countries?
„We have standards for this, such as PM9 (Phytosanitary Measures), which contain technical recommendations which can be used by a country to make contingenchy plans at national level against an organism. A country must also decide for itself questions like who pays for which aspects of the measures. For example, Ralstonia solanacearum, which causes wilt in cut roses, is already a PM9.”
Climate change and international trade are the most important factors of introduction and spreading?
„Yes, and a third factor is important: more knowledge. Perhaps we thought that an organism would not be present in a region, but through new diagnostics and more sensitive methods of detection we learn more and more about introduction and spreading.”
Does EPPO use models to predict the spread, for example?
„We use climate models, and a standard scenario for climate. We are also interested in spread models; many scientists have worked on these. Based upon such a model, for example, an appropriate size of buffer zone may be recommended, like the 10 km zone in case of an outbreak of Xylella (until now, as Brussels is changing this into 5 km). But it is difficult to answer the question: how big can the gap be between infected and not infected areas? And we are not yet able to use models routinely to answer such questions.” (picture: Donato Boscia)
Why is there no PM9 standard for Xylella?
„Because the EU, with advice from EFSA, has responded fairly quickly to the first outbreak, in southern Italy. We will consider incorporating that experience into a PM9 Standard. We have warned for many years of the risks from Xylella, but the particular threat to olive trees was not predicted. We have to look at reality and ask ourselves what can be introduced via import. But it is not easy to predict risks.”
The impact of EU rules after an Xylella outbreak is enormous.
„Yes, especially if that outbreak is in a nursery area. The impact of each quarantine organism can be large everywhere. One of my first tasks at EPPO was to map out for a training exercise the impact for Kew Gardens, if Anoplophora chinensis was found in those famous gardens in London. Which trees will be affected by this Asian longhorned beetle, and which ones will not? Learning from such a case should help our member countries to put in place technical solutions to the problem, after a finding or an outbreak.” (picture: NVWA)
Is an EU plant passport sufficient to contain a risk like Xylella?
„No system can guarantee 100%. Just look at New Zealand. The land is isolated in an ocean, the phytosanitary control is very strict and the public awareness about foreign organisms is very large. And yet new organisms can still enter NZ. If you want to prevent an outbreak of Xylella in, for example, Boskoop, EU rules are not enough.”
Great awareness and a lot of hygiene, thus, to reduce the risk?
„Yes, take hygienic measures. And see what measures you can take to reduce the risk further, and minimise the impact if there was to be a finding. That starts with traceability: know where your material comes from.”
Is North America stricter because import is often quarantined for a long time?
„The United States and Canada are strict on their borders, and also NZ, has even stricter rules. The introduction of soil pathogens is a risk, and therefore the European regime argues that importing soil as such is prohibited, but surprisingly you can import plants in soil. We would recommend against allowing imports other than in substrates which have been carefully evaluated.”
What does EPPO do to increase public awareness? Xylella finally came into Germany by a private individual who took an infected plant on holiday.
„We have helped out member countries to set up campaigns to inform the public about certain organisms, for example with posters at airports. We will also do more, but it is for the country or a region to set up a public campaign in its own language. Like Lombardy in Italy did against the Asian longhorned beetle.
It is also important that people know how to respond to a finding or outbreak. EPPO is working on guidance for our countries to help them with this. Who should they call? You have to be careful and do not give wrong information.”
Does that happen?
„Yes, by media. When ash dieback first occured in the UK, it was said that all British ash trees would be dead within a few years. We have since been criticised for being alarmist because many trees are still healthy! That was not information from Defra, the ministry where I worked, nor information from EPPO. It was the interpretation of journalists. You cannot keep that under control.” (picture: Centre for Genetic Resources)
Does the Brexit lead to stricter import requirements?
„I cannot comment on that. If the UK has left the EU indeed, I expect the UK to remain a member of EPPO. Norway and Switzerland are among 23 members of EPPO who are not in the EU.”
But are import requirements of non-EU countries stricter than those of EU countries?
„That’s hard to say; we do not monitor all requirements that countries set. EPPO prefers all countries to establish clear technically based import rules and publish them. But we still have some way to go on this, and in many cases rules are set as part of bilateral agreements. The technical basis may not be entirely clear.”
There may be rules, but must the supply chain also be transparent?
„Yes, that is true, and you have to rely on that. For example tracing seeds is difficult. Seeds can be stored in a country for a year, then moved to another country, and then sown in another country. That does not make plant health control easy.
Plant health is now such an important theme. That is why recently 2020 was declared the International Year of Plant Health. This has been promoted by Finland and will sponsored by the United Nations. EPPO will be taking part and helping to raise awareness of the importance of plant health.”
What will be the new Xylella?
„We do not know which organism, but what we do know is that more new organisms are coming towards us. Sometimes we do not even see them coming, as happened with Xylella in olive trees. Therefore, it is important that we continue to scan the horizon for possible new organisms that could threaten our trees and plants.” <
