Present situation of Erwinia amylovora in Switzerland
The first outbreaks of fireblight (Erwinia amylovora – EPPO A2 quarantine pest) were discovered in Switzerland in 1989, in the eastern part of the country (Solothurn and Zürich cantons). Since then, the disease has spread in the eastern part of Switzerland and its incidence has increased. In 1999, isolated outbreaks were observed for the first time in the western part, in the cantons of Vaud, Jura, Fribourg, Neuchâtel, Geneva and Ticino, mainly on ornamentals (Cotoneaster salicifolius) and also in a few commercial fruit orchards. 2000 was a very favourable year for the disease and severe attacks were noted in the German-speaking part of Switerland, in particular in apple orchards in Thurgau. In the French-speaking part and Ticino, the disease has rapidly spread (65 communes were concerned), and only the Valais canton remained free from fireblight (Cazelles ; Hasler, 2001). The present situation (as of mid-August 2001) is the following: in French-speaking Switzerland and Ticino only a few outbreaks were observed on ornamental plants (Cotoneaster salicifolius). 8 communes located in 3 cantons were concerned (1 in Neuchâtel, 1 in Ticino and 6 in Vaud). In this part of Switzerland, commercial orchards have not been found infected in 2001. The German-speaking part of Switzerland is more severely affected by fireblight. The numbers of infested communes per canton are the following: 11 in Aargau, 4 in Appenzell Innerrhoden, 20 in Appenzell Ausserrhoden, 7 in Bern, 2 in Basel, 20 in Luzern, 46 in St Gallen, 1 in Schaffhausen, 2 in Schwyz, 64 in Thurgau and 40 in Zürich. In the canton of Thurgau, approximately 30 orchards were found infected, and two of them showed high levels of infection. In the canton of St Gallen, among the six orchards concerned, two were severely infected. Infected fruit trees have been found in several cantons of the eastern part, as well as numerous infected plants of Cotoneaster dammeri. High infection levels have also been noted on Crataegus. Measures are being taken to prevent further spread of the disease. In a few communes, destruction of ornamental plants has been ordered. Prophylactic measures are being taken, and treatments (copper compounds) can be recommended in orchards where a high risk of infection is expected. Apparently, no fireblight has been reported from nurseries in 2001.
The situation of Erwinia amylovora in Switzerland can be described as follows: Present, mainly in the German-speaking part of the country, but isolated outbreaks have been found since 1999 in French-speaking cantons (except Valais) and in Ticino.
Sources
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Cazelles, O.; Hasler, T. (2001) Progression du feu bactérien en Suisse en 2000.
Revue suisse de viticulture, arboriculture, horticulture, 33(1), 17-21.
Site Web de la Station fédérale de recherches en production végétale, RAC, Changins, CH-1260 Nyon 1. Inspectorat phytosanitaire. Feu bactérien.
http://www.admin.ch/sar/scripts/get.pl?rac+recherches/pv/phytosan8_f.html+0+60
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