New discoveries on emerging postharvest diseases of apples in Northern Italy

Postharvest apple diseases are primarily caused by fungal pathogens entering fruits through wounds during harvesting, handling, and storage. Common wound pathogens include Penicillium spp., Botrytis spp., Rhizopus spp., and Mucor spp.. Latent pathogens, such as Neofabraea alba and N. kienholzii (bull’s eye rot) and Ramularia mali (dry lenticel rot), are increasingly significant in Italian apples, particularly in late-harvested varieties like Cripps Pink and Golden Delicious. Propagules of N. alba are present in rainwater, while R. mali transitions from an endophyte to an epiphyte before storage. White haze, linked to Entyloma, Golubevia, and Tilletiopsis species, is caused by epiphytic fungi present on fruit skin pre-harvest. Emerging pathogens such as Colletotrichum spp. (bitter rot) and Alternaria spp. (black rot) further threaten postharvest quality. Metabarcoding and qPCR analyses of fruit and aerial microbiomes provide insights into pathogen epidemiology, enabling targeted strategies for crop protection and disease prediction.