Biocontrol of Xylella and its vector in olive trees for integrated pest management
Olive cultivation in southern Europe is a long-standing tradition, one that has shaped the environment and the culture in many European countries. However, there is a growing threat to this part of history. Xylella fastidiosa is a pathogen that is increasingly causing diseases on olive trees and various other crops in the Mediterranean region. It wiped out a number of olive groves in Italy and Spain in only a few years, while infections have also been detected in France and Portugal. Unfortunately, the climate of the southern European Union is ideal for Xylella, and if the disease continues to spread, it could reduce yields of olive harvests by as much as 70 %.
Currently, there are no pesticides available on the market proven to be effective against Xylella, which is spread by xylem-feeding insects – notably the spittlebug – common in the Mediterranean climate. Farmers are often forced to destroy infected plants or use chemical insecticides, damaging incomes as well as organic production. BIOVEXO will demonstrate environmentally sustainable and economically viable plant protection solutions that can be deployed as a method of integrated pest management.
BIOVEXO’s approach involves developing biopesticides that target Xylella – X-biopesticides – and those that target the insects spreading the disease – V-biopesticides. The X-biopesticide candidates will be based on an onion extract (a food industry by-product) and antagonistic bacteria; the V-biopesticide candidates will be based on a plant extract (also a food industry by-product), a fungus and a microbial metabolite.
The overarching objective of the BIOVEXO project is to reduce the pressure and disease severity caused by Xylella in olive cultivation without an adverse environmental impact. This will help protect long-established olive orchards, which are integral to southern Europe’s history and culture. It will also preserve the cultural heritage and jobs provided by Europe’s olive orchards and permit the continuation of organic production methods. It also seeks to prevent Xylella infections becoming established in new olive plantations.
Within these, the BIOVEXO project has a number of specific objectives. These are:
- Optimising production of antagonistic bacteria and onion extract for targeting Xylella (X-biopesticides) for prevention and cure.
- Optimising production of the active substances targeting the spittlebugs that act as a transmission vector (V-biopesticides) and identifying the best application methods, thus reducing the likelihood of Xylella infection.
- Upscaling production of the prototypes of X- and V-biopesticides to prepare them for field trials. This involves producing qualities of up to 2000 litres at an industrially relevant scale.
- Performing large-scale validation of the pesticides as part of an integrated approach to pest management to provide data on efficacy.
- Determining the mechanistic effects and mode of action of the pesticides on their target organisms.
- Assessing the sustainability of the pesticides in terms of their environmental impacts over their full life cycle, to prove their superior environmental characteristics over existing solutions.
By achieving its overall objectives, the BIOVEXO project will bring potential new solutions to the challenges facing orchard owners in southern Europe. In addition, it will also make contributions to specific BBI KPIs through:
- Establishing at least two new cross-sectoral interconnections. One will be between the biotech industry, represented by ACIES, and biopesticide producers; the other will be between the biotech industry and the farmers.
- Creating at least six new bio-based value chains, as each of the biopesticides being developed represents a value chain of their own. Up to four of these will be tested in large-scale field trials.
- Contributing to developing at least two new products in the form of two biopesticides for large scale production in the coming years (one for Xylella and one for the insect transmission vector).
In addition, the BIOVEXO project will have a positive environmental impact, by offering the potential to switch to biological treatment options. While there is a limited amount of data available on the environmental footprint of vector-targeting biopesticides, some measures suggest potential reductions of up to 85 %. For the Xylella-targeting biopesticides, this should prevent the need to eradicate infected plants and the associated environmental damage.