Possibility of using an ozonized-solution sprayer in organic viticulture

The EU has set the target of a 50%-reduction of pesticides in agriculture by 2030, due to the increasing concerns about possible negative effects of these substances on the people (specif. the workers) and the environment. At the same time, organic farming techniques for the management of the vineyards are encouraged, even though maximum limits on the use of Copper- based substances are becoming increasingly stringent. To this end, a two-year field experimentation has been carried out in a vineyard near Udine (northern Italy) using an innovative sprayer able to instantaneously prepare and distribute ozonized water. The aim of these tests was to verify the effectiveness of this technical solution and the simultaneous possibility to limit the use of Copper or other pesticides in vineyards. The final yields of several theses in the same vineyard were hence quantified at the grape harvesting. The collected data evidenced a 100%-damage (hence the total loss of the grape production) within the untreated witness thesis. In the theses treated with different doses of Sulphur and Copper, it was also recorded a high damage, in this case characterized by an intensity decreasing with the used amount of those two substances, and, in any case, with production losses always exceeding 70%. Those results allow stating that even the defence techniques making use of different proportions of pesticides and ozonized water did not yield the desired results and led to an average decrease in the harvested crop of around 40%. The addition of ozonised solution to the treatments carried out, whatever the quantity used, was found to be completely ineffective, especially in a particularly difficult year for vineyard defence such as 2024, characterized by very frequent and intense rains. Concluding, the results referred to the observed year have evidenced that the application of ozonized water did not give any particular benefit, probably because the ozone, even if dissolved in an aqueous solution used to wet the vines’ canopy and not in its gaseous state, has no sufficient persistence of action to effectively contrast the pathogens.