Quackgrass-A Serious Problem Weed

Quackgrass (Elymus repens L. Gould) is a perennial problem weed of the cooler climates in the Northern Hemisphere. Quackgrass reproduction and spread, competition with crop plants, and quackgrass control methods are addressed in the article.

Nutrient Analysis Problems in Douglas-fir Christmas Trees

Christmas Tree
The results of an Oregon State University affiliated two year study on the nutrient levels of Douglas-fir trees on Oregon Christmas tree plantations. Samples were taken from trees four and five years old in the Corvallis, OR and Willamette Valley areas.

Necrotic Ringspot on Bluegrass Turf

Plant Disease
Research conducted at Washington State University's Western Research and Extension Center identified the cause of "necrotic ringspot" on bluegrass turf to be the fungus Leptosphaeria korrae. The authors discuss the signs and symptoms of the disease along with control methods.

Root Weevils: Some Adults Overwintered, Others are Still Emerging

A comprehensive guide for the management of root weevils including the strawberry root weevil (Otiorhynchus ovatus) in greenhouses, nurseries, landscapes and gardens. Topics discussed include root weevil damage, life cycle, hosts, and control.

Silver-Spotted Tiger Moths on Conifers

The silver-spotted tiger moth, Halisidota argentata, belongs to a family of stout bodied moths which can be pests of conifers, causing loss of harvestable trees for Christmas tree growers. Lifecycle, habitat, appearance, and control methods are briefly addressed.

Grovesiella Abieticola - Associated With a Canker Disease of True Firs

Grovesiella canker caused by the fungus Grovesiella abieticola was known to infect True fir in Northern California and B.C. Canada but was discovered on Noble fir Christmas tree farms in Western Oregon and Washington in the mid-1980's. Descriptions of the fungus and control methods are included in the article.

Swiss Needle Cast of Douglas-Fir

Plant Disease
Swiss needle cast (Phaeocryptopus gaumanni) is a fungal disease of Douglas-fir trees, native to the North American pacific coast, which causes needle and color loss. Topics discussed include, winter-spring symptoms, summer-fall symptoms, and control.

Pest News--Black Vine Weevil: An Increasing Problem for California Nurseries

Research was conducted on the distribution and chemical control of the black vine weevil in California nurseries after an increasing number of California nurseries were reporting control problems and damage associated with the black vine weevil.

Botrytis Cinerea

Plant Disease
Botrytis blight ( Botrytis cinerea), also known as grey mold, is one of the common diseases of greenhouse crops. Descriptions of general symptoms and symptoms on flowers, leaves, seedlings, and stems are provided along with cultural and chemical management programs.

Root Weevil Update

Information provided on an Oregon State University affiliated study conducted on root weevils and chemical control methods. The authors provide tables highlighting the results of the study for the foliar chemical applications and drench chemical applications.