Apulia is not famous for its coffee plantations, it’s in Italy. Yet it seems that Xylella fastidiosa, a bacterium associated with the death of thousands of olive trees, was imported from Costa Rica a few years ago with an infected coffee plant. The landscape and the local economy are paying the costs.
Ceratocystis platani, a microscopic fungus, seems to have been imported from the United States some eighty years ago through crates made of infected wood. Thousands of London planes along both roads and canals in Southern Europe are gone.
Phytophthora infestans seems to have been imported to Ireland in the mid-nineteenth century with a batch of infected potatoes. Since the cultivation of potatoes was the primary source of income and carbohydrates, misery, famine, death (about a million people) followed. For those who had the chance, emigration was the only chance.
The microfungus Cryphonectria parasitica, responsible for the desiccation of branches and stems of sweet chestnut, seems to have been imported from Japan to the United States at the end of the ‘800. In this case, recognizing the important role of the timber market in moving the parasite, in 1912 the US Congress issued the “Quarantine Act”, the first example of an attempt of disease containment by law. Despite this, the same parasite arrived in Europe a few years later.
Little was known yet, but today we do not know much more …
Exchange of goods worldwide cannot be stopped, but the inspection of those that could potentially be dangerous in the place of destination is possible. This is the reason why, sometimes with questionable technical times, the international quarantine regulations are constantly updated.
For Europe, we are talking about an EU Directive in which it is written the plant species at risk, which parts of them must be checked at boundaries, what to control, and so on.
Despite this effort, thanks to the presence of skillful phytosanitary inspectors, a small part of this material delivered from every corner of the world and arriving with a document certifying the lack of infections, is found infected. The consignement returns back home, or it’s disinfected at the harbour or arrival, or it’s destroyed.
A container of tomatoes, azaleas, bonsai or Christmas trees, however, to be inspected under a microscope can not be entirely damaged. For each type of goods there is an official sampling protocol that works 100% in a super-equipped laboratory, but much less in the dark of a container. Furthermore, there may be plants already infected but still with no symptoms, because the incubation times of diseases are long, sometimes years.
Despite this strong organization, therefore, it is inevitable that something escapes from the inspectors’ eyes. Unfortunately, this “something” is increasing year by year.
As long as all of us will continue to ask the grocery, the nursery or the gardener for exotic fruits and plants just because they are less expensive, or because they are more beautiful than the beautiful ones we already have, import of exotic diseases certainly will not slow down. We are all responsible for it.
Last year during an international meeting I said that “the growing importation of exotic pathogens is a bioindicator of human stupidity”.
Someone has taken it badly, but I still think so.