Situation of Grapevine flavescence dorée phytoplasma in Italy
Considering the economic importance of Grapevine flavescence dorée phytoplasma (EPPO A2 quarantine pest) surveys and compulsory control are being implemented in Italy. Efforts are also being made to identify the phytoplasma species which are associated with grapevine yellows.
So far, Grapevine flavescence dorée phytoplasma has only been found in northern Italy (Osler & Refatti, 2002). Its vector, Scaphoideus titanus, is present in most grapevine-growing areas of northern Italy. Severe outbreaks of the disease are observed in the grapevine-growing regions of Piemonte, Lombardia and Veneto. The disease is expanding in Liguria and Emilia-Romagna (Piacenza and Reggio Emilia) but growers are trying to delay or prevent its spread by eliminating diseased plants and controlling the vector. In areas where the first severe outbreaks of the disease had been detected and where the vector had been controlled, the number of new diseased grapevines is decreasing. Bois noir (stolbur) occurs practically in all regions of northern Italy and in several instances together with flavescence dorée. Symptoms of bois noir are rarely severe, and plant recovery may be observed. In the eastern provinces of Emilia-Romagna (Valtellina), in most part of Friuli-Venezia Giulia, and in the province of Trento (Trentino-Alto Adige) only bois noir is present.
Details on the situation in northern Italy
Emilia-Romagna: found recently in the west part of this region, particularly in the provinces of Piacenza, Reggio Emilia. Isolated foci were found in the province of Parma and Modena.
Liguria: found on the west part of the coast.
Lombardia: found in most parts of this region, severe outbreaks were seen in Oltrepó pavese and provinces of Mantova and Brescia. Isolated findings were made in the provinces of Cremona, Mantova, and Vicenza.
Friuli-Venezia Giulia: found near Pordenone (see EPPO RS 2003/042).
Piemonte: found in 3 provinces (Alessandria, Asti, and Cuneo).
Trentino-Alto Adige: first foci were found in 2001 near the infested zones in Veneto.
Veneto: found in a large part of this region (provinces of Padova, Treviso, Vicenza, Verona).
In central and southern Italy (Barba & Albanese, 2002), bois noir was frequently detected. Grapevine flavescence dorée phytoplasma was not detected, with the exception of one finding in Marche in 2002. The phytoplasma was detected in a few grapevines 35 years old, but its vector Scaphoideus titanus could not be found. Therefore, it is difficult to evaluate the significance from an epidemiological point of view of such finding. But this could indicate that there is a risk of spread of the disease towards the south of the country.
The situation of Grapevine flavescence dorée phytoplasma in Italy can be described as follows: Present, found in northern Italy (Emilia-Romagna, Liguria, Lombardia, Friuli-Venezia Guilia, Piemonte, Trentino-Alto Adige, Veneto), under official control.
Osler, R.; Refatti, E. (2002) [Focus on the grapevine phytoplasma diseases – Situation in northern Italy.]
Informatore Fitopatologico, 10, 42-48.
Barba, M.; Albanese, G. (2002) [Focus on the grapevine phytoplasma diseases – Situation in central-southern Italy.]
Informatore Fitopatologico, 10, 49-52.