If the olive trees on your land in Puglia are browning from the tips, losing whole branches and not recovering after rain, the likely cause is Xylella fastidiosa, and the honest answer to the title is no: there is still no cure. There is a lot you can do, and some of it is a legal duty. This guide explains how to recognise it, what the rules require, and where research on treatments stands, checked in October 2026.
Drive south from Lecce towards Gallipoli or Leuca and the scale is plain: grey, leafless groves on both sides of the road, some already cut to stumps, others with new green trees planted between the old trunks. Behind our house, two of the old trees went the same way within a couple of summers. It is a hard thing to watch in a landscape built around them.
What Xylella is
Xylella fastidiosa is a bacterium that lives in the xylem, the vessels that carry water through a plant. It is spread by insects that feed on xylem sap, above all the meadow spittlebug (Philaenus spumarius). The bacterium blocks the vessels, so water no longer reaches the leaves, and the result in olives is olive quick decline syndrome: leaf scorch, wilting and the death of whole branches.
It was first identified near Gallipoli in 2013. The strain in Puglia, subspecies pauca ST53, first called CoDiRO, has since killed millions of trees across Salento and moved north through the provinces of Brindisi, Taranto and Bari.
Early signs
- leaves that turn brown and dry from the tip and edges, as if burnt;
- wilting of leaves and branches, especially in dry weather;
- twigs and branches dying back from the ends, often on one side of the tree first;
- weak growth and falling yields.
Other problems, including drought stress and fungal disease, can look similar, so a visual check is only the start. Confirmation needs a laboratory test on leaf and twig samples. In Puglia, report suspected cases to the regional plant health service (Osservatorio Fitosanitario), which runs monitoring and testing.
Where it is now
The Region updates the official map of the demarcated area regularly. The update of 11 May 2026 recorded new isolated outbreaks at Mola di Bari and Noci, where the rules aim to eradicate the bacterium. Most of Salento is an infected zone where the aim is containment, with a containment strip and a buffer zone further north. Which zone your land is in decides what you must do, so check the current map before you plant, prune or move any plants.
What the rules require
Controlling the spittlebug is the most important step, because the insect carries the bacterium from tree to tree. Every spring the Region orders owners of olive groves and other land to plough, harrow, rotovate or mow to kill the young insects before they can fly. In 2026 the deadlines were 15 May in comuni below 200 metres above sea level and 30 May in those above. Insecticide treatments against adult insects may also be required in some zones.
Where the rules aim at eradication, and in the containment strip, infected trees must be removed and destroyed, and moving plants that could carry the bacterium or its insects is restricted. In March 2026 the regional administrative court (TAR Puglia) upheld the obligation to remove infected trees where the rules require it, monumental olives included. Like most of the measures across Italy, these rules apply to small gardens as well as farms.
Every April the sound of the season changes in the countryside around us: tractors and strimmers out at once in every grove, racing the spittlebug deadline before the grass gets too high.
Replanting
The main hope for rebuilding the worst-hit areas is replanting with tolerant varieties, which can live with the infection and still crop. The varieties authorised for replanting in the infected zone are chiefly Leccino and FS-17, also sold as Favolosa. Replanting rules and grants change, so ask the Osservatorio or a local agricultural association before you buy young trees.
What research says about treatments
Some infected trees have shown signs of recovery after experimental treatments. In a 2016 statement on these treatment approaches, the European Food Safety Authority (EFSA) made clear that they do not remove the bacterium; at best they improve the health of the tree.
EFSA reviewed field trials by two research groups: professors Carlucci and Lops of the University of Foggia, and Professor Scortichini of CREA. The trials combined fertilisers, fungicides and bioactive compounds, including zinc and copper formulations, sometimes with citric acid, together with careful pruning, tillage, weed control and irrigation. All treated trees still tested positive, but they grew more foliage and new shoots than untreated ones, and some produced a reasonable crop.
The EFSA Panel on Plant Health stressed that the findings were preliminary: the treatments did not remove the bacterium, their long-term effect was unknown, and multi-year studies were needed. It accepted that such treatments might extend the productive life of trees in infected areas, particularly in the containment zone.
What to do now
Report suspicious symptoms, meet the spring deadlines for working the soil, follow the plant health service’s instructions for your zone, and where trees are lost, replant with tolerant varieties. Pruning out affected branches can buy time, but it rarely saves a badly infected tree.
References
- EFSA Panel on Plant Health (PLH); Scientific Opinion on the risks to plant health posed by Xylella fastidiosa in the EU territory, with the identification and evaluation of risk reduction options. EFSA Journal 2015;13(1):3989.
- European Food Safety Authority (EFSA). 2019. Update of the Xylella spp. host plant database, systematic literature search up to 30 June 2018. EFSA Journal 2019;17(5):5666.
- Saponari, M., Boscia, D., Altamura, G., D’Attoma, G., Cavalieri, V., Di Carolo, M., … & Martelli, G.P. (2017). Isolation and pathogenicity of Xylella fastidiosa associated with olive quick decline syndrome in southern Italy. Scientific Reports, 7(1), 17723.
