Plasma activated water as a possible sustainable strategy towards grapevine yellows disease management

Plasma activated water (PAW) possesses significant antimicrobial properties due to the synergistic effect of reactive oxygen and nitrogen species (RONS) produced by the plasma treatment. To test its efficacy as plant resistance inducer, trials were carried out in five Glera and one Chardonnay vineyards in grapevine plants preliminary tested for the presence and identity of phytoplasmas. The PAW treatments were performed for two years injecting into the plant vascular tissues 10-20 ml of PAW or sterile distilled water (SDW) as control in a total of 130 plants (105 treated with PAW and 25 with SDW). A relevant number of PAW treated symptomatic plants showed a reduction of the symptoms, an higher number of the bunches and a higher berry weight per plant, compared to the SDW treated. Moreover the molecular analyses after the two year-treatment show a decrease of phytoplasma infected plant number treated with PAW (35.5%) compared with the SDW treated ones (12,5 %).