First Paragraph: Esca, also known as black measles, and Petri disease or young esca, are caused by a complex of fungal pathogens. Esca typically occurs in older grapevines and is caused primarily by Phaeoacremonium aleophilum (Togninia minima) as well as other species of Phaeoacremonium. Young esca, also known as vine decline as it occurs on immature grapevines, is typically caused by another closely related fungus Phaeomoniella chlamydospora. However, both of these fungi can be found in plants affected by both disorders. When diseased wood is obtained from nurseries or disease occurs in newly planted vineyards, symptoms can be seen in vines as young as two to three years of age.
