A severe case of pear decline disease

A recent severe outbreak of pear decline in a four month-old orchard in Northern Italy is reported. The symptom was seen since July 2019 in about 30% of the plants which increased to 80% by the end of the summer season. Molecular analyses confirmed the presence of the pear decline phytoplasma (16SrX-C), ‘Candidatus Phytoplasma pyri’ in symptomatic and asymptomatic leaf materials and also in the roots of the symptomatic plants. The infected plants belong to the cultivar Abate Fetel grafted to quince MA; considering the frequency of the symptom appearance after transplantation and its spread in the field it is very likely that the rootstock was already phytoplasma infected and contributed to the quick dissemination of the pathogen in the field that was also emphasized by the presence of low numbers of the pear decline phytoplasma insect vector Cacopsylla pyri. The orchard is under process of uprooting and will be replanted with phytoplasma-free tested materials.