First identification of Venturia asperata from atypical scab-like symptoms in Italian apple orchards

Atypical scab symptoms were reported for the first time at the end of July in 2012 in Northern Italy (Cesena province, Emilia Romagna region) on fruit apple cultivar CIVG198 Modi® carrying the Rvi6 (=Vf) major resistance gene to Venturia inaequalis; it is a hybrid of ‘Gala’ x ‘Liberty’ with more than half the total world production area of cv ‘Modi’ located in Italy. The symptoms were also established in all the following years and Venturia asperata was identified as a causal agent of these atypical scab symptoms through morphological studies and molecular analysis of conidia from fruits and ascospores from overwintered leaves, using specific primers for V. asperata, V. inaequalis and V. pirina. Pathogenicity tests carried out on fruit at different phenological stages showed only light symptoms. Venturia asperata could represent an emergent disease for cv ‘Modi’ and disease control may be necessary.