01878nas a2200157   4500008004100000022001400041245015100055210006900206260001600275300001400291490000800305520130900313100001801622700001501640856006501655       2016                        eng d  a0191-291700aEffects of Soil Solarization and Trichoderma asperellum on Soilborne Inoculum of Phytophthora ramorum and Phytophthora pini in Container Nurseries0 aEffects of Soil Solarization and Trichoderma asperellum on Soilb  cJan-02-2016  a438 - 4430 v1003 a<p>Infested container nursery beds are an important source of soilborne <em>Phytophthora</em> spp. for initiating disease through movement with surface water or splashing onto foliage. We investigated the effects of soil solarization, alone or with subsequent amendment with a <em>Trichoderma asperellum</em> biocontrol agent, on the survival of <em>Phytophthora</em> spp. inoculum. In field trials conducted with <em>Phytophthora ramorum</em> in San Rafael, CA and with <em>P. pini</em> in Corvallis, OR, infested rhododendron leaf inoculum was buried at 5, 15, and 30 cm below the soil surface. Solarization for 2 or 4 weeks during summer 2012 eliminated recovery of <em>Phytophthora</em> spp. buried at all depths in California trial 1, at 5 and 15 cm in California trial 2, but only at 5 cm in Oregon. There was no significant reduction of <em>Phytophthora</em> spp. recovery after <em>T. asperellum</em> application. Although the population densities of the introduced <em>T. asperellum</em> at the 5-cm depth were often two- to fourfold higher in solarized compared with nonsolarized plots, they were not significantly different (<em>P</em> = 0.052). Soil solarization appears to be a promising technique for disinfesting the upper layer of soil in container nurseries under certain conditions.</p>1 aFunahashi, F.1 aParke, J L  uhttp://apsjournals.apsnet.org/doi/10.1094/PDIS-04-15-0453-RE