Discusses options for managing major insect pests and diseases of conifers in Oregon forests: bark beetles, wood borers, and ambrosia beetles; defoliators; aphids, adelgids, and scale insects; terminal and branch insects and pitch moths; root diseases; stem decays; foliage diseases; canker diseases and canker-causing rust diseases; and mistletoes. Extensive references...
This publication discusses the environmental requirements of needle diseases, their potential impact on tree vigor, when disease levels signal a problem, and what you can do to minimize damage.
Previous studies have indicated that roots from five tree species (Picea sitchensis, Tsuga heterophylla, Pseudotsuga menziesii, Pinus ponderosa, and Pinus contorta) decompose at different rates across an environmental gradient in Oregon. Measurements of wood chemistry from each tree species as well as moisture and
temperature from each location do not...
White and grand fir are both valuable components of the mixed-conifer stand structure managed for late-successional reserves in central Oregon. However, they are often short-lived species because of high susceptibility to root diseases, defoliating insects, bark beetles, and wildfire. This study focuses on the effects of root diseases caused by...
The larvae, or “worms,” of sawflies resemble small, green caterpillars
that feed on the leaves of various plants. Although sawflies are
rarely an economically important problem in Oregon cereal crops, unusually large populations (300 larvae/10 sweeps) of one species, probably Pachynematus sp., were found in Umatilla County in 2003. The...
"Infestations of the spotted wing Drosophila fly (Diptera: Drosophilidae), an exotic pest, have been found in Oregon fruits in 13 counties. Of the 3,000 species of Drosophila, commonly known as vinegar flies, approximately 175 are known in North America. Two of these known species have been found to be harmful...
An important disease of Vitis vinifera production in Oregon and all other commercial growing regions is powdery mildew of grape, caused by the obligate fungal pathogen Uncinula necator (Schwein.) Burril. Grape production can be characterized as a long-term investment in the establishment and maintenance of the vineyard. Establishment times have...
A necrosis at the tip of cones was observed on hop (Humulus lupulus), cultivar "Nugget", grown in Oregon in the early 1990's. Fusarium sambucinum and F. avenaceum were recovered from symptomatic cones in 1998 and preliminary inoculation experiments suggested both Fusarium species could cause hop cone necrosis. Studies were carried...
Winter grain mite, Penthaleus major (Duges), is a small, colorful, cool season mite that damages grass and cereal crops throughout the Pacific Northwest as well as in most other temperate regions of the world. Hosts include most cereals and grasses of economic importance. Winter grain mite has been a frequent...
This publication reviews the growth stages of grapes. For each growth stage (or group of growth stages), the document lists the more effective pesticides used to control insects, weeds, and disease; their rates; and application timing for Oregon grape growers. It also covers the effectiveness of various fungicides for control...