Disease Risk of Potting Media Infested with Phytophthora ramorum Under Nursery Conditions

Phytophthora ramorum

Phytophthora ramorum in North America

Two apparently unlinked events marked the beginning of one of the most devastating forest diseases known to man in recent times: Sudden Oak Death (SOD). In the mid 1990s, while a novel species of Phytophthora was being isolated from mildly diseased Rhododendron and Viburnum plants in German and Belgian nurseries, the first reports of inexplicable death of tanoaks (Notholithocarpus densiflorus) ...

Evaluation of Potting Media for the Production of Rough Lemon Nursery Stock

Effect of different potting media on growth of rough lemon (Citrus jambhiri L.) rootstock was studied. Freshly harvested seeds of rough lemon were germinated in flat trays of sterilized sand under greenhouse conditions. Six week old seedlings, uniform in size were transplanted from trays to pots (15x15 cm). Leaf manure, peat, spent compost of oyster and button mushroom were added in different c...

Status of California’s Phytophthora ramorum Stream Survey

Since 2004, we have annually monitored Phytophthora ramorum in streams, creeks, and rivers throughout infested and at-risk areas of California by baiting with rhododendron leaves. This survey helps delineate the pathogen’s range and can quickly detect its spread. Our sites are dispersed from Del Norte to San Luis Obispo counties on the coast, and in Butte, El Dorado, Nevada, Placer, and Yuba Co...

Genetic Diversity of Phytophthora ramorum in Belgium

Phytophthora ramorum is thought to be an introduced pathogen in North America and in Europe based on the presence of only three clonal lineages. The North American lineages (NA1 and NA2) are responsible for infections in North American forests and nurseries, while the European lineage (EU1) is responsible for infections in Europe, mostly in nurseries. There have also been a few isolated finding...