Updated situation of ‘Candidatus Phytoplasma mali’ in Belgium
In Belgium, the presence of ‘Candidatus Phytoplasma mali’ (associated with apple proliferation – EPPO A2 List) was first confirmed in 2011. During a research project carried out from February 2009 until January 2011, this phytoplasma was detected in root samples collected from symptomatic and asymptomatic trees in 11 commercial and family apple orchards, as well as in psyllids captured in 2 apple orchards. These orchards, located in 6 different provinces (Hainaut, Liège, Limburg, Namur, Oost-Vlaanderen, and Vlaams-Brabant), had been selected because of the presence of symptoms or were neglected orchards (not always symptomatic). ‘Ca. P. mali’ was detected in each studied orchard (see EPPO RS 2011/132). As a consequence of these results, an extensive and systematic survey was carried out by the Federal Agency for the Safety of the Food Chain in 2011-2012 in 87 apple tree nurseries. In 2011, 368 leaf samples (each composed of 20 leaves from 4 different trees) were taken in 60 nurseries, and in 2012, 418 leaf samples were taken in 52 nurseries. Collected leaf samples were tested (PCR assays) by the national reference laboratory. During this 2 year- survey, ‘Ca. P. mali’ was detected in 5 nurseries located in the provinces of West-Vlaanderen, Luxembourg and Hainaut. All affected trees were destroyed and eradication measures were imposed in the nurseries concerned. Surveillance for ‘Ca. P. mali’ will continue in 2013. Finally, a research project has been launched and will focus on the distribution of ‘Ca. P. mali’, ‘Ca. P. pyri’ and the role of psyllid vectors.
The pest status of ‘Candidatus Phytoplasma mali’ in Belgium is officially stated as: Present, restricted distribution; under official control in nurseries.
NPPO of Belgium (2013-05).