Practical observations on the presence of AP disease (‘Candidatus Phytoplasma mali’) in Trentino (Italy)

An epidemic spread of apple proliferation, a disease caused by ‘Candidatus Phytoplasma mali’, started in Trentino (north-eastern Italy) in 1998. This disease was already known in this region, as its first report dates back to 1951, but this was the first time that it showed an epidemic behaviour, spreading over both mountain and bottom-valley environments. Since 2008 the distribution of this disease appears to be locally, again due to a typical “recovery” phenomenon. In this note some field observations carried out in two research projects, funded by Provincia di Trento (SMAP1 and SMAP2), are reported. Symptoms, transmission trials by insect vectors and root bridges, monitoring surveys, practical control experiences and examples for “recovery” are presented.