Antifungal Activity of ZnO and MgO Nanomaterials and Their Mixtures against Colletotrichum gloeosporioides Strains from Tropical Fruit

Avocado (Persea americana) and papaya (Carica papaya) are tropical fruits with high international demand. However, these commercially important crops are affected by the fungus Colletotrichum gloeosporioides, which causes anthracnose and results in significant economic losses. The antifungal activity of metal oxide nanomaterials (zinc oxide (ZnO), magnesium oxide (MgO), and ZnO:MgO and ZnO:Mg(OH)(2) composites) prepared under different conditions of synthesis was evaluated against strains of C. gloeosporioides obtained from papaya and avocado. All nanoparticles (NPs) at the tested concentrations significantly inhibited the germination of conidia and caused structural damage to the fungal cells. According to the radial growth test, the fungal strain obtained from avocado was more susceptible to the NPs than the strain obtained from papaya. The effect of the tested NPs on the fungal strains confirmed that these NPs could be used as strong antifungal agents against C. gloeosporioides to control anthracnose in tropical fruits.