XyIlella Fastidiosa, origin or symptom of one of the most serious crises in the Italian agricultural system. 5 years of even judicial battles and diatribes still seeking solutions. History, analysis and evidence of a solution that comes from Made in Italy scientific research, already successfully tested but still undervalued. With a view to conserving olive trees and restoring depressed ecosystems.
Apulian olive growers, 5 years of battles
February 2019 Will be remembered by farming communities in Italy for the sheep milk crisis in Sardinia, but also for the one of the olive growers at Apulia. The ‘orange vests’ have been trying for months to draw attention to the woes that plague them, Xylella Fastidiosa and missed reimbursements for the February 2018 frost. In addition to inefficiency,
ça va sans dir.
, of the Rural Development Plan (RDP).
The battle of Apulian olive growers has continued unabated since October 2013, when the Regional Phytosanitary Service was informed of the probable presence of Xylella Fastidiosa on some olive trees near Gallipoli (Le). The Puglia region immediately took the first steps, to try to eradicate the pathogen or at least stem its spread. The infected territory was zoned, setting a schedule of interventions for plant and land management due to proximity to outbreaks. (1)
Minister Gian Marco Centinaio, by decree 14.2.19, adopted the ‘Intervention Plan for the revitalization of the agricultural and agribusiness sector in the territories affected by Xylella‘. With a total allocation of 100.65 million euros (48.05 from MiPAAFT, 52.60 from the Region) to compensate, at least in part, for the damage caused by the phytopathy that is damaging olive trees. In addition to the 30 million euros allocated by the Interministerial Committee for Economic Planning (CIPE) on 9.2.19 to the new ‘Contingency Plan for the Containment of Xylella Fastidiosa. (2)
Xylella Fastidiosa
, the symptom of the crisis
Xylella Fastidiosa
is an asporigenic gram-negative bacterium that colonizes the xylem vessels of plants and occludes them, preventing sap from reaching any part of the plant. Symptoms are often similar to those resulting from water stress (leaf bruscature, desiccation of branches and portions of the canopy). And it is not easy to identify them at the first infection, as they occur even after a year.
The plant continues its biological cycle and produces healthy fruit (albeit in smaller quantities), until the bacterium reaches the roots, prevents it from absorbing nutrients and thus leads it to death. The bacterium has several sub-species (ST53 strain, in Apulia) and spreads through different vectors. Such as the Sputacchina Media, Philaenus Spumarius, which feeds on the tender leaves of olive trees and spreads the bacterium to other plants.
The spittoon can travel as much as 100 meters per week and thus spread the pathogen with potential rapidity (also due to possible passive travel, via vehicles and wind). It is precisely for this reason that rapid and incisive intervention would have been useful, but it has been slowed down by scientific uncertainties about the bacterial strain and subsequent diatribes. (3)
The pathogenicity of the bacterium is still being questioned by some quarters, although the scientific community has exhibited proof of this through demonstration of the so-called Koch postulates. Indeed, some consider the depletion of soils due to the massive use of pesticides and herbicides (rather than the presence of wood fungi and the lepidopteran Zeuzera Pyrina) as the primary cause of plant diseases.
Xylella, the Italian-European debate.
The discordant positions have garnered support from associations and politicians interested in protecting olive growers (or more likely their own votes and favors) in the face of the most drastic prospect, the eradication of olive trees. Invariably, the conspiracy theory surfaced, with the result that most olive growers felt ‘safe’ without needing to do anything to try to stem the contagion or save their plants.
The European Commission intervened with two subsequent measures:
– in 2014 Brussels banned ‘the movement of plants intended for planting out of the province of Lecce, Puglia region, Italy.’ Ordering annual official inspections to ascertain the presence of the Xylella bacterium and ordering member states to provide for the collection of reports on at-risk territories,
– in 2015 then ordered the most drastic measure, eradication. To be extended to all potential host plants of the bacterium within 100 m of the infected olive tree, regardless of their apparent health status. (4)
In 2016, the EU Court of Justice ended three years of debate. Stating that the eradication requirement is ‘appropriate and necessary’ to ensure a high level of phytosanitary protection in the European Union. (5) Taking into account Efsa’s expressed scientific assessments that there is no cure to plant disease. Although ‘it is possible that changes made to cropping systems (e.g., pruning, fertilization, and irrigation) may have some impact on the disease, but this is generally not enough to cure the plants.’ (6)
Therefore, in 2017, the Lazio and Puglia Regional Administrative Courts rejected countless administrative appeals against orders to uproot infected trees, affirming the priority of interest in safeguarding plant health and the duty to apply the precautionary principle.
In January 2019, Bari prosecutors ordered the seizure of an infected olive tree found in Monopoli. Garnering harsh criticism from the spokesmen of the ‘orange vests’ and Confagricoltura, who are instead calling for a green light to eradicate any plant that tests positive. As early as 2015, the Lecce Public Prosecutor’s Office obtained the preventive seizure of some of the plants, impeaching Commissioner Giuseppe Silletti (delegated to manage the Xylella emergency) and 9 other experts.
Xylella
, the traveling bacterium
The disease advances northward, where the Apulia Region gradually redefines the boundaries of ‘demarcated’ areas (infected zones and buffer zones). Since 2013, the affected area has expanded from 8 thousand hectares (in the province of Lecce alone) to 715 thousand hectares. The entire provinces of Lecce and Brindisi, much of the province of Taranto, and some municipalities in the Bari area. 36 percent of the region, about 21 million trees (out of a total of 60).
One third of Italian olive oil is produced in Puglia (40-45% extra virgin, 30-35% virgin, 25-30% lampante), where olive production expresses 15 percent by value of regional agricultural production. Plant disease has reportedly contributed to the cessation of operations of about 400 mills over the past 5 years. The Centinaio Decree will now be implemented by assigning roles and responsibilities, simplifying the
iter
of eradication and incentive for replanting of
cultivars
that tolerate the bacteria (e.g. Leccino, Favolosa FS17).
However, other outbreaks of different sub-species have already been reported in Spain, as well as in France. Curbing the spread of the bacterium thus appears wishful thinking, if not entirely utopian. Rather, without losing hope, we need to stimulate the resilience of those same plants that already nourish the economies of the world’s two leading olive oil producers, Spain and Italy precisely. Respecting the original cultivars, perhaps even.
Olive trees in Salento, the underlying problem.
The olive tree in Salento is a traditionally poor crop, with infrequent marginality, historically intended to produce lamp oil (lampante, in fact). Saving on running has always been an imperative, to the point that olives were picked from nets thrown on the ground and taken to the mill after several days, with no hurry or care for the oxidation of the drupes.
The land, however, was being worked, at least under the plants. Until systematic chemical weeding took over human labor. (7) Resulting in zero organic matter in soils. Olive growers believed they were saving money (the harder the soil, the better they worked) and instead caused the pre-desertification of soils (below which there is often limestone rock). Water and systemic stress.
Biologist and phytopathologist Margherita D’Amico, head of the project ‘Eco-friendly control systems against Codiro,’ noted that precisely in Salento, the dominant plant species are those resistant to glyphosate. Therefore, proposing to investigate whether and to what extent the broad-spectrum herbicide has afflicted the roots, which in diseased olive trees in Salento have often been found to be rotten.
Scientific research conducted in Apulia following the emergency, according to the researcher, has never considered the root system. Although international studies conducted on the bacterium, as early as 2004, we have shown the deterioration of xylema in trees. That is, the tissue of vascular plants, from roots to leaves, used to conduct raw sap (i.e., water and the solutes dissolved in it).
In turn, the study of olive groves conducted by the University of Basilicata over 15 years highlights the need for analysis of soils and roots (of plants infected with the bacterium as well as those exposed to related risks, for the purpose of accurate diagnosis of the problems to be addressed. Where the deficiency of organic substances already in itself constitutes a premise for a variety of pathologies and unproductivity, with respect to which intervention to restore the lost balance is indispensable. (8)
Mycorrhizae, the solution
Made in Italy
at your fingertips
‘
Biodiversity
Of an agricultural soil, Xylella cause or consequence?
‘ Giusto Giovannetti – brilliant biologist at the Center for Experimental Crops(CCS
) in Aosta, which the writer had the honor of knowing back in the day-he has been working for decades on microbial bacteria to promote plant health, resilience and growth. In fact, microbial communities intervene in the rhizosphere (from the Greek
rhìza
, root and
sphàira
, sphere), that is, the portion of soil around the roots from which plants absorb the nutrients and water they need to grow. Through mycorrhizae.
Mycorrhizae (from Greek mikos, fungus, and rhìza, root) are symbiotic associations between soil fungi and non-lignified plant roots. The host plant gives up organic matter (sugars, proteins, vitamins) to the fungus and achieves better absorption of nutrients. Where mycorrhizae develop (as in nature, near 90 percent of trees in forests) plants are healthier, more vigorous, and less susceptible to environmental stresses. (9)
The experiment conducted on 1350 olive trees in Presicce (LE) with a group of farmers from ‘Sustainable Salento‘ was based on an intervention to restore the microbial stock of the soils by inoculating a high concentration of microbial biota. Thus, the metabolic function of olive trees was reactivated, with more than positive results. In fact, after the treatments, ricacci were evident on the main and secondary branches, as well as basal suckers even on already dry sections.
The
cocktail
of microbiota
used has been produced by CCS in Valle D’aosta for several decades and is regularly used to improve soil health. The vascular system of the plant is itself rich in biota, which is precisely absorbed by healthy soil. Microorganisms, for millions of years, have been a living part of plants and animals and thus activate a kind of ‘positive epidemic.’ The ‘super-organism’ tends to recover functions weakened by stressful conditions by rebalancing symbiotic activity. With an intervention in some ways analogous to what can be accomplished with prebiotics on the microbiome human.
Conclusions. System crisis or brain crisis?
Since the mid-20th century microorganisms (considered pathogens) were considered enemies. And it appeared reasonable at the time to plan for its elimination. The mistake, however, that is repeated-and no longer justifiable in the current state of research-is instead to continue destroying indispensable microorganisms under the pretext of destroying harmful ones. This approach is already being revised in medicine, where probiotics often prove more effective than antibiotics, on which widespread resistance has accrued. And it is time for it to be reconsidered in agronomy as well.
‘
To combat the bacteria
it is necessary to look at the olive grove as a whole and improve its “immune system” by adopting sustainable agronomic practices that enhance the plants’ ability to counteract biotic and abiotic stresses. By doing so, it is possible to live with the bacterium while limiting its spread and recovering infected plants‘. (10)
Eradication of millions of olive trees – today in Apulia, tomorrow who knows – will benefit the economy of the sectors concerned in the short term. No wonder, then, that the vultures funded by the seed monopolies and pesticides hymn funding to devastate and rebuild. The question remains whether it is right for us and our children to persist in destroying thehabitat And its unique landscapes. Instead of caring for the ecosystem and the
biodiversity
, developing a healthy economy free from standardized seeds, herbicides and
pesticides
.
Dario Dongo
(with the collaboration of Marina De Nobili and Guido Cortese. Cover photo by Alberto Mileti)
Notes
(1) In fact, in the face of the immediate danger of spreading harmful organisms such as the one under consideration, member states must take interim protective measures. See dir. 2000/29/EC, ‘on protective measures against the introduction into the Community of organisms harmful to plants or plant products and against their spread within the Community‘
(2) To supplement the Agriculture Operational Plan, with use of residual funds from the 2014-2020 Development and Cohesion Fund.
(3) Xylella Fastidiosa had been extensively studied in other areas of the planet (especially in the U.S., where Pierce’s disease caused by it affected grapevines) but not as much in Europe
(4) See Decisions (EU) 2014/497 and 2015/789, both on ‘measures to prevent the introduction and spread within the Union of Xylella fastidiosa (Wells et al.)‘. The European Commission, after putting the Italian government on notice, referred Italy to the Court of Justice in December 2015. And the sentence (of conviction, in all likelihood) is still awaited
(5) ECJ, joined cases C 78/16 and C 79/16, judgment 9.6.16
(6) See EFSA opinions 6.1.15 and 20.3.15. Margherita Ciervo, a geographer at the University of Foggia, notes how both European Food Safety Authority documents lack scientific evidence on hypothetical eradication successes
(7) Lecce and Brindisi provinces topped the podium for herbicide consumption (Istat data, 2003-2008)
(8) See Cristos Xiloyannis, Adriano Sofo, Assunta Maria Palese (2015). ‘
Against Xylella from olive trees, good agronomic practices.
‘. The Agricultural Informant, 19-2015, https://www.scribd.com/document/378573314/Xylella-articolo-Xiloyannis#download
(9) On mycorrhizae and CSS work, see also.
https://www.arsacweb.it/wp-content/uploads/2016/07/Opuscolo-funghi-micorrizici.pdf
(10) See note 8
Dario Dongo, lawyer and journalist, PhD in international food law, founder of WIISE (FARE - GIFT - Food Times) and Égalité.
Graduated in law in Trento, she follows a master's degree in food law at Roma Tre. She is passionate about food and wine, she is between culture and tradition.
Computer scientist and professional beekeeper. A former conscientious objector, he served and then volunteered in a canteen for the homeless in Turin. He deals with the right to food, food policy, food sovereignty and biodiversity. He founded the association of Metropolitan Pollinators with the aim of defending biodiversity through specific projects of social and environmental regeneration. He represents the Slow Food Community of Metropolitan Pollinators. He promoted the birth of the national network of urban beekeepers. He directs an independent agricultural market, collaborates and writes for Egalitè (Onlus Rome) which deals with defending the rights of disadvantaged people, and with the newspapers Great ItalianFood Trade, Qualiformaggio, L'apicoltore Italiano and minor magazines.
