Wrap-up from a Consortium Meeting and Field Trip to Alicante on April 20-22nd, 2022.
Alicante is a historic Mediterranean port and the coast around it is a famous vacation place both for Spaniards and for the rest of Europe.
Alicante city | photo pixabay
The main crops grown in the province of Alicante are citrus fruit and various nuts, including almonds and walnuts. Almond trees are the plants most affected by Xylella fastidiosa in Alicante. This is also the case of the trees in BIOVEXO experimental farms in Tarbena.
Tarbena, a community in the north of the Alicante province
Since over a year, BIOVEXO through its partner ASAJA runs experiment with numerous BIOVEXO products against Xylella in the eradiation zone in Northern Alicante in the Es Figueral estate of José Tomás Mascáro. It is a farm of ca. 12,000 m2 that he inherited from his ancestors.
BIOVEXO experimental farm No. 1
Tomás’ plots were formerly planted with vineyards that disappeared due to phylloxera at the beginning of the 20th century. He has currently about 500 almond trees placed on terraces supported by stone walls. Some trees are over 50 years old, but most are young trees that have been replanted within the last 15 years. There are also about 50 carob trees that are older. Before the Xylella fastidiosa plague, the approximate production of almonds was 3500 Kg. Nowadays, however, the almond production is only about 5% of those past years.
Tomás Mascáro, our first host in Tarbena in front of his finca, passionate about his groves
BIOVEXO develops biological solutions to limit the impact of the disease on the trees affected, as well as to limit the transmitting power of the insects spreading the bacterium. Whereas its main focus is on olive trees, in Alicante and in Mallorca we test the effectiveness of our products also on almond trees. In this particular orchard of José Tomás, no Xylella symptoms have been observed in time zero of the experimentation, thus it has been selected for testing of products for preventive treatment.
Preventive treatment in farm No. 1
José Tómas decided to offer his marcona almond trees for BIOVEXO testing both because they are directly affected by the pest, and because they see the importance of scientific research in developing solutions against Xylella and similar plagues. At the moment, unfortunately, the only effective tool to stop the pandemic is abandonment and eradication of the trees infected.
The only treatment available at the moment – eradication
The small-scale experimentation of BIOVEXO consists of applying BIOVEXO products to six different groups of trees, plus one group of trees remains untreated to serve as a control group. We test three products, each applied via foliar spray and via irrigation. Products are applied every 20-30 days, and effects are checked regularly, visually, and, at the end of the treatment, at the end of October, where the leaves will be inspected by a qPCR.
Manual Lucena, ASAJA, explaining BIOVEXO trials
The second farm BIOVEXO works with, the Rafalet farm, belongs to Miguel Angel Salvà. It is also a farm inherited from his ancestors, a bit smaller, with an area of 7,000 m2. Formerly, it was also planted with vineyards that disappeared and was replanted with 190 almond trees almost a century ago. This farm is located at the flat top of a hill and the average production before the plague was 2,200 kg of almonds annually. It is heavily infected already by Xylella and consists of two parts: one part where all trees have been cut and removed, and a second part where they still stand. Unfortunately, the almond yield is so low that it is not economically feasible to harvest the crop.
BIOVEXO experimental farm No. 2: eradicated section in the front, still standing section in the back
In the remaining trees, BIOVEXO experiments have just started and, unlike in the first farm, the treatment here is curative. First, dead branches of the trees are cut off and then the three most promising BIOVEXO treatments from recent preventive tests are applied. Worth noticing is that some of the trees produce beautiful oval almonds endemic to the region of Tarbena.
Affected trees suitable for treatment in farm No. 2
Whereas the farmers receive compensation from the government for eradicating the sick trees, neither of the farmers, Miguel explains, accept any money for making their farms available to BIOVEXO. They do it for the benefit of science.
Mateo Signes, Tarbena, believer both in science and in eradication of sick trees
Fortunately, not everywhere in Spain is the situation as drastic as in Tarbena. Large almond farms north of the Cànyoles valley in the neighbouring province of Valencia are for example quite prosperous and not affected at all. However, one has to be vigilant, raise awareness and apply proper measures before it becomes too late there as well.
No sign of Xylella infection on almond trees in the neighbouring province of Valencia | photo Josep Pocalles