Abstract :
At the begititiing of spring 1996, raised, brown areas
along the bark of trunk and twigs were observed on
young apple trees in Piedmont (northern Italy). In many
cases the epidermis flaked off. Longitudinal cracks
accompanied by necrosis of the tissues beneath the bark
were also observed. In one orchard the disease caused the
death of 2500 trees. Biochemical, nutritional and pathogenicity
tests, as well as the comparison of whole-cell
protein profiles of the isolates with type-strains, indicated
that Pseudomonas syringae pv. syringae was the causal
agetit of the disease. Bacterial blister bark remains a
threat for apple cultivation also in Italy, especially in
orchards planted in sandy soils
