BRUSSELS – From 2012 to 2017, Xylella fastidiosa seriously damaged about 6.5 million olive trees in Puglia. These are some of the new estimates on the impact of the bacterium presented at the second xylella conference of the European Food Safety Authority (EFSA), in Ajaccio. From 28 to 30 October in the Corsican capital over 350 scientists, institutional representatives and trade associations of farmers and nurserymen met to take stock of the fight against new plant pathogens. Mainly Xylella fastidiosa, considered by the EU to be public enemy number one. The parasite detected for the first time in 2013 by researchers from the Institute for the Sustainable Protection of Plants (Ipsp) of the Cnr of Bari is the one with the greatest potential impact in economic, social and environmental terms in Europe, as certified by a study by the Joint Research Center of the Commission.
The ‘three days’ of work began with the concluding conference of the Ponte research project, the first funded by the EU to also investigate xylella, which since 2015 has involved 25 organizations from Europe and third countries. Ponte made it possible, among other things, to experiment with methods of early remote detection and to start tests on resistant olive varieties in Puglia. A work that will continue with the EU XF-Actors project, the preliminary results of which were discussed at the second Efsa conference, on 29 and 30 October. On the resistant varieties, a simulation of the University of Wageningen showed how in the current situation the economic damage for the olive growers alone, not counting the oil industry, in Greece, Italy and Spain could reach nine billion euros in 50 years . With the replanting it would go down to 4. On the control of Xylella, encouraging data come from California, where bacteria are being tested capable of substantially reducing the infection on the vine.
The researchers of the Ipsp-Cnr of Bari are experimenting the same type of solutions on the olive tree and have presented in Ajaccio the evidence that the Apulian strain of the bacterium does not infect the vine, laying the foundations for the free marketing of 26 varieties from the nurseries of the infected area in Puglia. “Since the first conference two years ago, research has expanded – says Giuseppe Stancanelli of Efsa – today we know much more about the vectors that transmit the bacterium, about the development of the disease and its control”. The range of subspecies and strains that have colonized different territories in Europe, with different impacts, is also known and broader. In short, if in the years following 2013 we looked at the Xylella fastidiosa as a unique specimen, now the situation is more complex. Based on the new knowledge, in the first months of 2020 the European Commission should present a proposal to the EU countries to update the control measures on the pathogen.