Italian authorities are facing an uncontrolled spread of an infection that threatens olive tree plantations as well as citrus and vineyards. According to the European Commission, about 10% of olive trees in the province of Lecce are infected with Xylella fastidiosa bacteria. If measures to contain the disease are not taken soon, Italy faces an economic crisis.
Insects feeding on the sap of plants contribute significantly to the spread of the disease. Some scientists are of the opinion that seemingly healthy plants can also act as carriers of the bacteria, so systematic cutting down only diseased specimens may not produce the desired result. According to Italian officials, the creation of 15-kilometer buffer strips around plantations of infected trees should, with a certain degree of probability, stop the increase in the focus of infection.
The presumed cause of the disease in Italy is ornamental plants, which were imported from Costa Rica. However, there is another theory, which was put forward by the Italian research group Peacelink: the threat to olive plantations is not the bacterium Xylella fastidiosa, but a fungus. The basis for this claim was the results of a spring 2014 study in which more than 500 trees were saved by treating them with antifungal compounds. Thus, says the Peacelink group, the mass cutting of diseased trees in the province of Lecce may not be justified.