On the use of food additives for the growth of fruit trees as antifungal agents

Typical commercial antifungals such as SCHOLAR® and PENBOTEC® are applied as washing solutions after harvesting and at the beginning of the fruit preservation process in cold storage. Unfortunately, these antifungals suffer from loss of activity after a few years of use, due to the development of resistance by the fungal strains. Our research activity aims to possibly replace currently used antifungals with solutions of salts widely employed as soil nutrients during fruit growth and ripening, to be applied also as washing solutions after harvesting. Preliminary results show that the Al(III) and Zn(II) salts possess a high antifungal activity by inhibiting the sporulation of P. expansum, P. citrinum, C. gloeosporioides, and M. piriformis, and in the case of Zn(II) salts the efficiency is even superior to the previously mentioned antifungals. Further studies are underway to evaluate the minimum inhibitory concentrations from in vivo tests directly on fruit and to identify the mechanism of action.