Olive trees affected by Xylella fastidiosa

An olive tree in Italy is infected with the lethal bacterium Xylella fastidiosa, which can now be detected early by aerial surveillance. Credit: Juan A. Navas-Cortes

Imaging

'Eyes in the sky' spot hidden threat to Italy’s olive trees

Airborne sensors find early signs of lethal infection.

A remote-sensing system can detect signs of a devastating infection in olive groves before trees show visible symptoms.

An outbreak of the deadly and incurable disease caused by the bacterium Xylella fastidiosa has destroyed olive groves in southern Italy and threatens to spread to the rest of Europe. Pablo Zarco-Tejada at the European Commission’s Joint Research Centre in Ispra, Italy, and his colleagues surveyed 15 olive groves using an aircraft carrying both a thermal camera and a hyperspectral sensor, which makes high-resolution measurements across a wide range of wavelengths.

The sensor system detects biochemical and physiological changes that can indicate onset of the disease in trees. Trees that were identified as undergoing such changes went on to develop visible symptoms at twice the rate of trees that free of such changes.

Early diagnosis of infection can help to contain the disease, the authors say.