Ozonated water was tested to control powdery mildew development. Two approaches were conducted: one to test the curative effect of ozonated water (application after the first contamination of the fungus), the other as a complement to biosolutions. For the latter approach, the hypothesis to be tested was to use ozonated water as a solution destroying the endogenous micro-organisms to facilitate the implantation of the biosolutions tested. Thus, the ozonated water treatment took place 24 hours before the application of the biosolutions. The production of the ozonated water was carried out using a laboratory prototype developed by the company AGROZONO. The work carried out did not identify any effect of ozonated water in either case. On the other hand, we were able to confirm the limit of this type of solution in the sense that the ozonation of the water had a very short life span (5 to 10 minutes).
The way we worked, producing small quantities of ozonated water and applying it manually within 30 minutes of manufacture, showed us that the quantity of ozonated water was very small or even zero. We were therefore unable to judge the real effectiveness of ozonated water. In 2022 we plan to work with an on-board ozonated water production machine on the sprayer to ensure that the ozonated water is applied as soon as it is produced.