Apulia has a significant heritage of centuries-old olive groves. In this social context, an olive tree is no ‘ordinary’ tree, they are not just perceived as a source of income central to local agri-food production, but take on an exquisitely symbolic and identity-making importance.
In 2013 olive trees in southern Apulia were signaled to show leaf desiccation symptoms. A plant disease called CoDiRo (Complesso da Disseccamento Rapido dell'Olivo) [OQDS, Olive Quick Decline Syndrome]. The drying up of leaves reported in olive plants becomes soon the object of scientific investigation. Initially, the symptoms were attributed to the presence of the Zeuzera pyrina insect, fungi and the bacterium Xylella fastidiosa (Xf). After further investigations, it became evident the main etiological role played by the bacterium Xf.
Hence shifting the construction of the plant pathology from a Complex of Causes to a Complex of symptoms identifiable in one sole cause (the bacterium Xf)
Xf is a vector-transmitted bacterial plant pathogen associated with serious diseases in a wide range of plants a bacterium that occludes the xylematic vessel of the host plant causing its decline, a plant pathogen whose presence triggers immediate eradication and containment measures wherever it appears in the EPPO region.
A few days after the Italian authorities’ notification of the presence of Xf in Salento, the Apulia Regional Council approved compulsory measures to control the Xf epidemic have been designed and implemented. The measures are based on an integrated pest management strategy that includes insecticide applications against the vector, agronomic measures to suppress nymphal stages of the vector on weeds and removal of infected and uninfected host plants. Demarcated areas and a buffer zone have been introduced across the peninsula to try and stop Xf spreading further northward.
The enormous discontent about the measures aimed to the removal of olive trees created a strong sentiment of distrust not only towards the institutions, but also toward the conduct of scientific research and the research institutes involved in the research on the plant pathology. Social and environmental movements reject the Xf>OQDS correlation, identifying alternative or contributory causes of the disease (i.e. fungi, soil pollution, and overuse of agro-chemical products). The eradication and containment of plans have encountered strong opposition from informal assemblages of local environmentalists, social activists, small organic growers, independent journalists, and political figures, who advocate, instead, an expansion of research efforts to find less drastic solutions with the ultimate goal of curing olive orchards instead of eradicating them.
Strategies used by these social movements are different and, in some way, have changed over time.
Their initial activities were mainly focused on a strong and physical opposition to the eradication measures, via public demonstrations, blockades, and by interrupting the removal of infected olive trees. Often the interruption of the mandatory phytosanitary policies (such as the removal of olive trees) was made possible via the use of legal proceedings to local courts. Another important strategy used by these movements is the organization of public seminars, workshops and meetings aimed at disseminating their 'counter-knowledge' about what they think is worthy of knowing on the plant pathology (i.e. its multi-causal etiology, and the alternative agricultural techniques aimed at coping with it). Another strategy, that brings us to more recent time, is the participation to actual research projects funded by the regional administration. In fact in year 2018, some of the member of these movements were given the opportunity to put in practice some lines of research on the multi-causality and the possibility to cure already infected olive trees.
It must be stressed that these movements are composed mainly by environmental and civic activists, (sometime even scientists from other disciplines), whose main goal is to preserve the symbolic significance of centuries old olive trees, to re-discuss agricultural policies, and to bring in the discussion of the problem an holistic approach that does not only focus on the bacterium, but questions on the different biotic, abiotic, environmental and even political- economical and social criticalities that, in their view, have allowed the pathogen to spread, or have allowed the olive trees to dry up in the first place. Their narrative is very complex and goes from a just struggle from epistemic democracy to the display of conspiracy theory like stances; from an understandable battle for the renegotiation of mandatory policies to the negation of the pathogenicity of the bacterium.
The great majority of olive oil growers in Apulia does not support these social movements, on the contrary they invoke a more decisive application of phytosanitary policies to stop the pathogen as soon as possible.