Update on the situation of Meloidogyne chitwoodi and Meloidogyne fallax in Sweden
In Sweden, Meloidogyne chitwoodi (EPPO A2 List) was first found in October 2017 (EPPO RS 2018/031, RS 2018/195), and Meloidogyne fallax (EPPO A2 List) in 2018 (RS 2019/038). Official phytosanitary measures have been taken to reduce the nematode populations and avoid any further spread. Regular monitoring is conducted. The NPPO of Sweden has provided updates on the situation of these nematodes and reported new outbreaks. In all cases, phytosanitary measures are applied and include restrictions on movements of soil and machinery, as well as cropping restrictions, monitoring of the fields during 2023, and tracing back and tracing forward analysis.
- Meloidogyne chitwoodi
In the initial outbreak in Sölvesborg (Blekinge county), soil sampling did not detect the pest in 2019 and 2020, but 1 larva was detected in 2021. Black fallow was applied to the field and no second stage juvenile (J2) larvae were detected in 2022. In the neighbouring municipality of Kristianstad (Skåne county), as soil sampling did not detect the pest for 3 years (2019-2022) all cropping restrictions were lifted.
New outbreaks were found in 2022 and 2023. M. chitwoodi was detected in the municipality of Skara (Västra Götaland county, about 300 km north of Sölvesborg and Kristianstad) in November 2022, in the framework of soil sampling done before planting seed potatoes. Trace-back investigations showed that the seed potatoes which had been used in that field had been produced in Hörby (Skåne county). Sampling in the field in Hörby detected the presence of both M. chitwoodi and M. fallax. In addition, M. chitwoodi was detected in another field in Hörby.
The pest status of Meloidogyne chitwoodi in Sweden is officially declared as: Present, under eradication.
- Meloidogyne fallax
The first outbreak was detected in the municipality of Kristianstad (Skåne county) in 2018. Since then, several other outbreaks have been found in the demarcated area. M. fallax was also detected in the municipality of Laholm in 2020 (RS 2020/172) and further investigation also detected M. chitwoodi in that field.
In 2021 M. fallax was also detected in the municipalities of Sölvesborg (Blekinge county), Höganäs (Skåne county), and Skara (Västra Götaland county). Measures were applied and soil sampling did not detect second stage juvenile (J2) larvae in 2022.
The pest status of Meloidogyne fallax in Sweden is officially declared as: Present, under eradication.
Sources
NPPO of Sweden (2023-01, 2023-06).