Update on the situation of Phytophthora austrocedrae in the United Kingdom
In the United Kingdom, the presence of Phytophthora austrocedrae was first detected in 2011 on Chamaecyparis nootkatensis and C. lawsoniana in a park in Scotland (East Renfrewshire, EPPO RS 2011/135). The pathogen was later found on Juniperus communis in northern England, in the Upper Teesdale National Nature Reserve (EPPO RS 2012/057). In 2012, the following new detections of P. austrocedrae on J. communis were made:
- on 7 trees in a heathland site in Perth and Kinross (Scotland)
- on 1 tree a private garden in Devon (South West England)
- at 3 different sites in Cumbria (North West England) in the natural environment, infection covering an area of approximately 14.5 ha (100% infection), 40 ha (10% infection), 70 ha (5% infection), respectively
- in a lot of 15;000 plants in a nursery in Cumbria (it was estimated that 5% of the plants were infected)
- 13 plants in a nursery in Devon.
In addition, investigations have been carried out at 1 site (100 ha) at Glen Artney (Scotland), on a dieback condition which has been affecting junipers for a rather long period (first noted prior to 2004). These ongoing investigations have revealed numerous juniper bushes showing symptoms of dieback apparently associated with lower stem and root necrosis. Laboratory analysis (isolation, molecular tests) confirmed the presence of P. austrocedrae in diseased plants. The ITS sequences obtained were similar to those from junipers in the Upper Teesdale Nature Reserve and those reported from Scotland in 2011 on C. nootokatensis and C. lawsoniana. Phytosanitary measures are being taken in the United Kingdom to contain the disease in the natural environment. In affected nurseries, as well as in the private garden, all infected material has been destroyed.
The pest status of Phytophthora austrocedrae in the United Kingdom is officially declared as: Present in some areas, subject to official control.
NPPO of the United Kingdom (2012-05).