Longevity of active Phytophthora ramorum in terminal tree hosts following the removal of primary sporulating hosts
| Authors: | Barnaby Wylder, Mick Biddle, Anna Harris, Joan Webber |
| Year: | 2017 |
| Type: | General Technical Report |
| Station: | Pacific Southwest Research Station |
| Source: | Proceedings of the sudden oak death sixth science symposium. Gen. Tech. Rep. GTR-PSW-255. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station: 104. |
Abstract
The Forestry Commission-managed forest estate located in Plym, Devon (southwest England) was one of the first locations in late summer 2009 to have stands of Larix kaempferi (Japanese larch) confirmed as infected with Phytophthora ramorum (EU1 lineage). The 398 ha forest had a high proportion (>30%) of L. kaempferi showing catastrophic levels of P. ramorum infection with trees of all ages affected to some extent. Although a few infected rhododendron were present, larch was the primary sporulating host so all larch trees were removed from Plym forest between 2009-2011 as part of disease management. Prior to removal however, the spores released from infected foliage on larch trees had already initiated dieback and bole cankers in a wide range of non-sporulating coniferous and broadleaved trees that were either part of the understory or present in stands next to the infected L. kaempferi.