First Experience with Ozone Used in Fruit Tree Storage

In the present study we investigated the possibility to use air ozone in fruit tree storage. The variables were: rate of ozonization, length of exposure to ozonized air and storage temperature. We assessed the impact of ozone on the vitality of the trees or bench grafted rootstocks, any changes appearing after storage and the feasibility of this technique under real conditions. Supplementary research was done to test the impact of ozonization on the potential occurrence of microorganisms and pests on trees. Results showed that trees can withstand relatively high rates of ozonization except for peach which is the most sensitive fruit; all the ozonization treatments impaired peach vitality. Other species withstand three months of storage in 1 °C and one hour of exposure to ozone in fortnight intervals without a significant impact on their vitality. A higher (5 °C) storage temperature with or without ozonization decreased the vitality of trees. Although it has been proved that ozonization can suppress damage‑causing microorganisms (bacteria and fungi) on trees, the fortnight frequency of ozonization did not prevent mould to develop. Results also indicated the potential effect of ozonization on the disinfestation of plant material from overwintering pests. The main operation restrictions of ozone exposure is the ability of ozone to decompose some materials and that it is harmful to human health.