Widespread Phytophthora infestations in European nurseries put forest, semi-natural and horticultural ecosystems at high risk of Phytophthora diseases

摘要: An analysis of incidence Phytophthora spp. in 732 European nurseries producing forest transplants, larger specimen trees, landscape plants and ornamentals, plus 2525 areas which trees shrubs were planted, is presented based on work conducted by 37 research groups 23 countries between 1972 2013. Forty-nine taxa recorded 670 (91.5%); within these nurseries, 1614 1992 nursery stands (81.0%) infested, although most affected appeared healthy. In plantings, 56 recovered from 1667 tested sites (66.0%). Affected frequently showed symptoms such as crown thinning, chlorosis dieback caused extensive fine root losses and/or collar rot. Many well-known highly damaging host-Phytophthora combinations detected but 297 407 new Phytophthora-host associations also observed respectively. On average, 1.3 species/taxa per infested stand planting site isolated. At least 47 the 68 plantings exotic species several are considered well established both Europe. Seven known found for first time Europe, while 10 had not been previously or plantings; addition, 5 detections woody plant species. unknown to science. The reasons failures biosecurity implications semi-natural ecosystems possible ways improve discussed.