Epidemiological aspects of ‘Candidatus Phytoplasma pyri’ transmission

Studies were carried out on pear decline epidemic in an experimental field located in Pignataro Maggiore (Caserta, Italy) where ‘William’, ‘Comice’ and ‘Conference’, pear varieties were grafted on the rootstocks ‘Quince A’ (EMA), ‘Farold 333’, ‘Quince C’, Farold 282’, ‘Farold 40’, ‘Farold 87’, ‘BP1’, ‘Farold 51’ and assessed their different susceptibility to ‘Candidatus phytoplasma pyri’ infection. The research continued to study susceptibility of Pyrus betulaefolia and a selection of Cydonia oblonga, Quince BA29 rootstocks. Five plants for each of the same three varieties, grafted on the two rootstocks were used for graft and insect inoculation with ‘Ca. P. pyri’ and controlled for two years for symptom expression and pathogen presence. None of the combination studied showed differences in susceptibility to the pathogen.