Olive quick decline syndrome

Olive quick decline syndrome
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

An infected olive grove in Italy in 2019

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]

Impact

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

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]

See also

• Xylella fastidiosa § Symptoms
• Citrus greening disease

References

1. Olive Quick Decline Syndrome (PDF), Primary Industries and Regions SA, 2017
2. Stokstad, Erik (8 May 2015). "Italy's olives under siege". Science. 348 (6235): 620. doi:10.1126/science.348.6235.620. ISSN 0036-8075. PMID 25953988.
3. Martelli, Giovanni P. (1 February 2016). "The current status of the quick decline syndrome of olive in southern Italy". Phytoparasitica. 44 (1): 1–10. doi:10.1007/s12600-015-0498-6. ISSN 1876-7184. S2CID 18746881.
4. Schneider, Kevin; Werf, Wopke van der; Cendoya, Martina; Mourits, Monique; Navas-Cortés, Juan A.; Vicent, Antonio; Lansink, Alfons Oude (28 April 2020). "Impact of Xylella fastidiosa subspecies pauca in European olives". Proceedings of the National Academy of Sciences. 117 (17): 9250–9259. doi:10.1073/pnas.1912206117. ISSN 0027-8424. PMC 7196823. PMID 32284411.
5. McGrath, Matt (13 April 2020). "Deadly olive tree disease 'could cost billions'". BBC News. Retrieved 5 May 2020.
6. Saponari, M.; Boscia, D.; Altamura, G.; Loconsole, G.; Zicca, S.; D’Attoma, G.; Morelli, M.; Palmisano, F.; Saponari, A.; Tavano, D.; Savino, V. N. (18 December 2017). "Isolation and pathogenicity of Xylella fastidiosa associated to the olive quick decline syndrome in southern Italy". Scientific Reports. 7 (1): 17723. doi:10.1038/s41598-017-17957-z. ISSN 2045-2322. PMC 5735170. PMID 29255232.
7. Martelli, G. P.; Boscia, D.; Porcelli, F.; Saponari, M. (1 February 2016). "The olive quick decline syndrome in south-east Italy: a threatening phytosanitary emergency". European Journal of Plant Pathology. 144 (2): 235–243. doi:10.1007/s10658-015-0784-7. ISSN 1573-8469. S2CID 16126474.