New website focusing on species of Phytophthora launched by OSU Professor Jennifer Parke.

Forest Phytophthoras of the World is an international resource for the latest information on ten major species of Phytopthora.

Hearing date set for possible expansion of the Sudden Oak Death (SOD) quarantine area in Southern Oregon.

A hearing is scheduled to discuss proposed changes to the quarantine area and allow use of an oak from disease free area.

Root Death in the Landscape

Nursery Crops
A discussion about the importance of plant root health in the landscape environment and the factors that can influence root system health. The authors address a variety of topics that influence root health ranging from nursery production methods to landscape practices.

Cold Tolerance of Container-grown Green Ash Trees Is Influenced by Nitrogen Fertilizer Type and Rate

Nursery Crops
Container-grown ‘Summit’ green ash (Fraxinus pennsylvanica) trees were used in a recent study in an effort to determine whether cold tolerance of the tree's buds and stems are related to nitrogen (N) application rate and fertilizer form.

Bud Necrosis of Green Ash Nursery Trees Is Influenced by Nitrogen Availability and Fertilizer Type

Nursery Crops
Nursery-grown green ash (Fraxinus pennsylvanica ‘Summit’) trees were tested to determine the relationship between the nitrogen (N) status of the trees in the fall and bud necrosis during the following spring. The results of the study and it's implications are discussed by the authors.

Spraying Leaves of Pear Nursery Trees with Urea and Copper Ethylenediaminetetraacetic Acid Alters Tree Nitrogen Concentration without Influencing Tree Susceptibility to Phytophthora syringae

Nursery Crops
An investigation was conducted into the increased susceptibility of pear nursery trees to infection by Phytophthora syringae following fall foliar sprays of urea which increased nitrogen (N) content in the trees. The authors discuss the methods and materials involved in the experiments along with the results.

Tree Growth Stage and Environment After Pathogen Inoculation Alters Susceptibility of Pear Trees to Phytophthora Canker

Nursery Crops
The results of an investigation on pear (Pyrus communis L. OHF97) to determine whether specific factors influence the tree's susceptibility to Phytophthora syringae Klebahn. The factors included tree growth stage, nitrogen (N) status, wound age, and infection environment.

Christmas Tree Weed Identification and Control

Christmas Tree
Informative look at weed identification and control in Christmas tree production by Oregon State University affiliated researchers, Ed Peachey and Chal Langren.

Fertilization of Nordmann and Noble fir

Christmas Tree
Field trials testing the effects of fertilization on Nordmann and Noble fir trees in relation to the Christmas tree industry, the results of the trials and the implications for growers are discussed.

The “ Best” Seed Sources for Christmas Trees

Christmas Tree
Information provided on Christmas tree seed sources and a review of research and collections in Turkey by Oregon State University affiliated researcher, Chal Landgren.