Slovenia was recognized as free from Erwinia amylovora until 2001. A low incidence of the disease was reported in 2001 and 2002 in the north-west uplands of the Gorenjska region. In 2001, only 3 trees in extensive orchards were found positive at one location out of 791 monitoring locations all over the country. In 2002, the same location in Naklo and a second one in a 1-km radius were found positive, whilst 875 other monitoring locations were fireblight-free. Despite strict phytosanitary measures implemented after discovery of the first focus, the bacterium spread in 2003 to the entire Gorenjska region, with further spread towards eastern and southern Slovenia. The NPPO registered 184 new foci by the end of the season in Gorenjska. Twenty-three foci are scattered in other regions. Phytosanitary measures were applied in every focus. Spread of the bacterium was probably enabled by favourable weather conditions, the presence of the inoculum and intensive bee-hive movement, resulting in flower infections. Since eradication has not been successful, it is concluded that E. amylovora is now present at low prevalence in Slovenia.

After causing damage in Asia and the USA, Dryocosmus kuriphilus Yasumatsu recently established in Europe on Castanea. The first outbreak in Europe occurred at a C. sativa nursery for production of plants for planting in Cuneo (Piemonte, Italy) in 2002. The Piemonte official service notified Slovenia that a consignment originating from an infested nursery was sold to Slovenia. Prompt phytosanitary action was taken in Slovenia in 2005 in order to trace back plants from this consignment and prevent establishment of the pest. In the period 2006–2009, intensive surveys of forests and fruit production areas showed absence of the pest in the majority of the Slovenian territory, including the demarcated area from 2005. An earlier introduction of infested plants from Cuneo in January 2004 remained undiscovered until 2007. Despite the radical measure of eliminating the infested orchard and removing infested Castanea trees in the forest bordering this orchard, the pest was not eradicated in this outbreak area. Individual infested trees in the forest were confirmed at a distance of up to 10–34 km in 2008, and a further 15 km in 2009. The results of annual surveys, eradication campaigns based on generic contingency elements and the change of strategy after the finding of infested forests are presented.

Sharka, caused by Plum pox potyvirus (PPV), was first observed in Slovenia in 1987. In the following years, the presence of PPV was confirmed by DAS‐ELISA in samples originating from orchards, individual trees and propagation material of stone fruits. In 1998, a systematic survey was initiated to prevent and control the spread of sharka and to establish pest‐free production sites. In the first 3 years of the systematic survey, the presence of PPV was also monitored outside production sites for propagating material and their buffer zones, in order to establish the current incidence of sharka in Slovenia. The results showed an overall presence of PPV infection in Slovenia. Since 2000, the survey has focused mainly on nurseries, mother trees and stool‐beds. In spite of strict official supervision and eradication measures, the incidence of sharka in propagating material production sites increased until 2002. A significant decrease in the number of PPV‐infected mother trees, stool‐beds, nurseries and buffer zones was finally obtained in 2002, as a consequence of the vast effort dedicated to containment of sharka in Slovenia.