Olive quick decline syndrome | |
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![]() An olive grove infested with Xylella fastidiosa in Apulia, Italy in 2019 | |
Common names | OQDS |
Causal agents | Xylella fastidiosa |
Hosts | Olive trees |
Vectors | Meadow froghopper |
Distribution | Southern Italy |
Symptoms | Dieback of the leaves, twigs and branches |
Olive quick decline syndrome (OQDS) (in Italian: Complesso del Disseccamento Rapido dell'Olivo, CDRO or CoDiRo) is a wasting disease of olive trees which causes dieback of the leaves, twigs and branches so that the trees no longer produce crops of olives. The main cause is a strain of the bacterium, Xylella fastidiosa, which is spread by plant-sucking insects such as the meadow froghopper. The bacteria restrict the flow of sap within the tree and so choke its extremities.[1]
The disease particularly affects olive groves in Southern Italy. It was first detected in Italy in 2013,[2] in the Salento Peninsula; by late 2013, it was estimated that approximately 8,000 hectares were affected.[3] As of 2020, the disease was threatening olive groves and oil production in Italy, Greece, and Spain, which together account for 95% of European oil production.[4][5] One 2020 model predicts a potential economic impact of the disease for Italy over 50 years between 1.9 billion to 5.6 billion Euros.[4]
In addition to Europe, the disease has also been detected in olive crops in California, Argentina and Brazil.[6]
Symptoms include leaf scorch and desiccation of twigs and branches, beginning at the upper part of the crown and then moving to the rest of the tree, which acquires a burned look.[7]