First report of Grapevine flavescence dorée phytoplasma in Hungary
The NPPO of Hungary recently informed the EPPO Secretariat of the first confirmed record of Grapevine flavescence dorée phytoplasma (EPPO A2 List) on its territory. At the end of August 2013, flavescence dorée was detected in 2 locations (Lenti and Kerkateskánd) in the county of Zala (Southwestern Hungary) during a specific survey carried out in a region bordering Slovenia where the disease occurs. The identity of the pathogen was confirmed by the Plant Health and Molecular Biology National Reference Laboratory of the NPPO using molecular methods: 1) for plant samples: multiplex-nested PCR (following EPPO Standard PM 7/79) confirmed by real-time PCR and sequencing; 2) for insect vector samples: real-time PCR.
- At Lenti, Grapevine flavescence dorée phytoplasma was found in grapevine (Vitis vinifolia) and Clematis vitalba plants in 1 household vineyard (500 m², about 500 vines). Symptoms of grapevine yellows were observed in approximately 5 % of the plants, and 4 out of the 6 collected grapevine samples tested positive for Grapevine flavescence dorée phytoplasma. Two samples were collected from an adjacent vineyard but gave negative results. A sample of C. vitalba collected in the vicinity of the vineyard was also found to be infected. In this locality, no specimens of the insect vector, Scaphoideus titanus, could be caught during the survey. An infected area of 1 km radius has been delimited around the affected vineyard, with a buffer zone of 3 km radius around the infected area.
- At Kerkateskánd, Grapevine flavescence dorée phytoplasma was detected in the insect vector, Scaphoideus titanus, and in C. vitalba plants in 1 household vineyard (2500 m², about 1000 vines). Grapevine plants growing in this vineyard did not show any symptoms. An infected area of 1 km area has been delimited around the affected clematis plants.
The possible origin of these infections is unknown, but the close proximity with infected vineyards in Slovenia strongly suggests that the disease has spread naturally from these infected areas to Hungary.
The following phytosanitary measures are being implemented to contain the disease.
- In infected areas:
- prohibition to move propagating and planting material;
- intensive survey of all vine-growing areas, including sampling and testing;
- removal and destruction of plants (roots included) of Vitis sp. and C.;alba which test positive for this phytoplasma, as well as of all Vitis plants showing characteristic symptoms of grapevine yellows;
- application of emergency chemical treatments in 2013 against S. titanus on behalf of the NPPO, mandatory chemical treatments will then be performed by growers in the following years.
- In the buffer zone:
- survey to determine the incidence of plants showing characteristic symptoms of grapevine yellows, including sampling and testing;
- removal and destruction of plants with confirmed positive laboratory test.
- application of mandatory chemical treatments to be performed by growers in the following years.
Finally, a nation-wide information campaign has been launched to draw the attention of grapevine-growers and the general public to the need for preventive actions to stop the spread of the disease.
The pest status of Grapevine flavescence dorée phytoplasma in Hungary is officially declared as: Present, only in some areas (Southwestern Hungary).
NPPO of Hungary (2013-09).