Italiano English
Download PDF

There comes a bacterium from America: it is alert phytosanitary

A new bacterium was imported from American continete and is capable of causing extensive damage to olive trees. It's called Xylella fastidiosa and in Italy it was found in the Puglia region in the Salento area, during the last summer. The affected plants have experienced a sharp deterioration coming, in extreme cases even death. The infestation currently covers an area of about 10,000 hectares of olive groves and has a very fast progression.

Dissemination and alert. Xylella fastidiosa bacterium is new for Italy and for Europe: the reporting of Salento is the first in Europe and is the only bacterium included in Annex I (parasites of maximum danger ) of the European plant protection regulation and Italian ( D. Decree 214/ 05 and subsequent amendments ). Until now it was only present in continete American of citrus, almond and other species. In the literature, in fact, Xylella fastidiosa is reported as dangerous parasite lives and citrus. However, it has 3-4 subspecies and that arrived in Italy is the subspecies that affects the olive, oleander, oak and almond trees. In Puglia, for now, there were no reports of damage to citrus groves and vineyards. A bacterium from the "black list ", and rightly so, given its importance infectious. It is gram negative bacterium, slow-growing, isolated and described in the U.S. from Pierce in 1987. In nature it would be in a latent state in many plants, especially grasses, which serve as inoculum for insect vectors, in our case the buzzer Homolodisca vitripennis or Cicadella viridis or other leafhopper, carried out through the bite to eat. Many plants will have to be torn down, with serious consequences for the production that will inevitably have a negative fallout on an economic level. For the moment, as a precaution, to nurseries in the area has been imposed ban on the marketing of the species, since we still do not know the true extent of this phenomenon and its harmful consequences. Even the Tuscany Region has disclosed a note inviting the local nurserymen to pay particular attention to susceptible crops.

Symptoms and struggle. The bacterial disease causes yellowing dellel start a showy leaves, due to dehydration, followed by a significant leaf drop and a general deterioration of the plant, until the death of the plant. In Italy it is not allowed the use of antibiotics in agriculture on a large scale and it is undeniable, also, the difficulty of reaching the bacteria within the xylem vessels. In the USA, in the laboratory was effective l ' exposure to temperatures of -5 degrees C, although it is impossible to ' application in the field.

In Photo: damage on citrus fruit (M. Scortichini, Experimental Institute for Fruit, Rome)



It's called Xylella fastidiosa, attacking olive trees, citrus and other species has already provided extensive damage in Salento.