«Hands off the olive trees!»: the epistemic war in the Xylella fastidiosa epidemic in Italy. A Computer-Assisted Text Analysis of User-generated content on social media

From Firenze University Press Journal: Cambio

University of Florence
3 min readNov 18, 2022

Giuseppe Tipaldo, University of Turin

Fabio Bruno, Quaerys srl

Sara Rocutto, University of Turin

During the summer of 2013, a series of farmers from Salento, Apulia’s southern sub-region (Italy), noticed an alarming phenomenon: a group of olive trees showed signs of desiccation, and pruning did not seem to have any positive effect. The symptoms appeared to be so aggressive that the first trees were already dying, while the surrounding plants were beginning to get sick.The olive growers turned to Dr. Donato Boscia, head of the Bari branch of the Italian National Institute for the sustainable protection of plants (IPSP-CNR), who asked his mentor, Prof. Giovanni Martelli, for advice.

Martelli, Professor Emeritus at the University of Bari, was among the leading experts on Xylella fastidiosa (hereinafter referred to as X. fastidiosa or simply X.), a bacterium — hitherto unobserved in Europe — which has infested many American crops for over a century and a half, including Brazilian citrus groves, Costa Rican oleanders and Californian vines. Here, X. has caused Pierce’s disease, which manifests itself with a pathogenesis quite similar to that observed in the Salento area (Bassi et alii 2016; Almeida et alii 2008; Efsa 2016; 2015).In October 2013, analyses conducted by Boscia’s team demonstrated that the disease — named «Olive Quick Decline Syndrome» (OQDS) — was indisputably associated with the presence of X. DNA on all the dis-eased plants. Within a month, the Regional Council of Apulia issued an emergency plan (Regione-Puglia Dgr 2023/2013), approved by the European Food Safety Authority (Efsa 2013): since there was (and still is) no cure, the only possible options to prevent an outbreak were pruning, eradication of trees with symptoms, and use of chemical treatments against vector insects (Saponari et alii 2014).

General Giuseppe Silletti of the Forest Police was appointed Commissioner of the Italian government for the emergency in the Apulia region, with the assignment to contain the epidemic. His measures required eradicating every plant showing symptoms of OQDS and all the asymptomatic plants in a radius of one hundred metres. Along with the first eradications of infected plants, however, tensions arose; the olive trees are admittedly part of the cultural heritage that has forged the social identity of local communities. Between 2014 and 2015, Maria Luisa Mastrogiovanni — a local journalist — came into the limelight because of the doubts she raised about the spontaneous appearance of OQDS. She first mentioned an illegal intervention by the Monsanto corporation and then attributed some responsibilities to the group of IPSP-CNR researchers who had isolated the bacterium: in her account, in 2010 X. would have escaped from their laboratory during a test. Both theories were endorsed and amplified on social media by well-known Italian opinion leaders (i.e. comedians and bloggers Beppe Grillo and Sabina Guzzanti), as well as some prominent politicians belonging to the 5 Star Movement (M5S), a populist, anti-establishment national party (Pirro 2018; Tipaldo, Pisciotta 2014).

Therefore, on 18 December 2015, the public prosecutor’s office in Lecce (the province capital) ordered the emergency seizure of all olive trees destined for eradication. General Silletti and five scientists (including team leader Boscia) were charged with the culpable outbreak of plant disease. The action, in fact, neutralised the «Silletti plan», and the General himself would resign less than a week later. Meanwhile, the new Apulia governor, Mr. Michele Emiliano, welcomed the justice intervention, declaring that the region was ready to support any alternative solution to cure the epidemic which did not involve the felling of the olive trees.For the following four years, various solutions were tested, but none proved effective in containing the epidemic (Elbeaino et alii 2014; Haelterman et alii 2015 ; Bassi et alii 2016; Coletta-Filho et alii 2016; Logrieco et alii2016; Boscia et alii 2017; Saponari et alii 2017; Luvisi et alii 2017; Bucci 2018; Scortichini et alii 2019). W hen, in May 2019, the accusations of the judiciary were dismissed, millions of olive trees had already been lost. As of 2022, the disease has become endemic, attacking centuries-old olive trees in the province of Bari, more than 250 km north of the area where the first outbreak took place in 2013.

DOI: https://doi.org/10.36253/cambio-12308

Read Full Text: https://oaj.fupress.net/index.php/cambio/article/view/12308



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