The Termoxyvid R&D project is coming to an end with important advances in the application of thermotherapy to control the Xylella fastidiosa bacterium on vine rootstocks at an industrial level. Furthermore, it has been possible to ensure that the treatment carried out does not have a detrimental effect on the plant material.
The initiative has been developed over three years and has been supported by the company Viveros Enrique Bravo, the Research Institute of Vine and Wine of the University of León, as well as the financial support of the CDTI through ERDF funds of the European Union.
The project began with the challenge of using, for the first time, thermotherapy to tackle the harmful bacterium Xylella fastidiosa. Although this technique had already been applied at an industrial level to control fungal diseases of vine wood in plants, Termoxyvid proposed its use in vine rootstocks against this bacterium that can cause so much damage in vineyards.
Despite the fact that, until then, the application of hot water treatment on vine rootstocks had not been proven, the main challenge that Termoxyvid addressed was, precisely, to demonstrate and endorse the effectiveness of thermotherapy on vine rootstocks, using a non-pathogenic bioindicator microorganism, and without damaging the plant material.
Among the technical results obtained, firstly, the determination of Stenotrophomonas maltophilia as the appropriate bioindicator bacterium to address the initial challenge of Termoxyvid stands out.
This bacterium is more tolerant than Xylella fastidiosa to temperatures above 37ºC, making it a good bio-indicator. It has even been observed that in the laboratory it has been able to grow at 45ºC.
With regard to the application of standard thermotherapy conditions on an industrial scale (50ºC / 45 minutes), this technique has been shown to be highly effective for all the varieties tested in the control of the bioindicator bacterium. Thus, given that the thermal resistance of the bioindicator bacterium is much higher than that of Xylella fastidiosa, Termoxyvid confirms that the thermotherapy treatment is «tremendously effective» in the control of this bacterium in rootstocks.