Phytophthora austrocedrae detected on Juniperus communis in the United Kingdom
As reported in the EPPO RS 2011/135, the presence of Phytophthora austrocedrae was detected for the first time in the United Kingdom in spring 2011. So far, P. austrocedrae had only been recorded in Argentina on Austrocedrus chilensis (causing ‘mal del cipres’ in Patagonia). In the United Kingdom, P. autrocedrae was discovered in a public park in Scotland (East Renfrewshire) on Chamaecyparis nootkatensis (2 trees) and C. lawsoniana (3 trees), and eradication measures were taken. In November 2011, P. austrocedrae was also found on Juniperus communis in northern England, in the Upper Teesdale National Nature Reserve. This reserve has the second most extensive area of juniper habitat in the United Kingdom, comprising 200 ha. Investigations showed that numerous juniper bushes were showing symptoms of dieback apparently associated with lower stem and root necrosis. The presence of P. austrocedrae was detected in samples collected from 6 trees (isolation and molecular diagnosis). Subsequent enquiry revealed that P. austrocedrae had been previously diagnosed on symptomatic J. communis in other sites: once from a garden in Mid Glamorgan and twice during nursery surveys. Another suspicious case in Devon is currently being investigated. This is the first time that P. austrocedrae is reported on J. communis; previously it was only known to occur on Austrocedrus chinensis, Chamaecyparis lawsoniana and C. nootkatensis. Surveys are being conducted to determine the extent of the disease on J. communis and phytosanitary measures are being taken to prevent any further spread.
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 (2012-01).