Pseudomonas Syringae Damage Increasing in Some Nursery-Grown Shade Trees

Plant Disease
Increased damage by Pseudomonas syringae, a bacterial disease, was noticed on a variety of nursery-grown shade trees. Research was conducted to determine how the bacterium was spreading, conditions encouraging infection, and possible control methods.

Grafted Tree Survival Increased, Grafting Season Extended by Inexpensive Hot-Callusing Device

Studies were conducted to test the effectiveness of using a hot-callusing device when grafting a variety of different trees. The authors discuss the results of the hot-callusing method and it's effects on apple, peach, pear, prune, and Douglas-fir trees.

Every Christmas Tree a '10'

Christmas tree
The idea of using clones in the Christmas tree industry is debated by the Oregon State University affiliated author. The use of clones could lead to more uniform sellable trees but could also lead to a lack of genetic diversity in the Christmas tree industry.

Pine Needle Sheath Mite Damages Ornamental Pines in the Pacific Northwest

The pine needle sheath mite, Trisetacus campnodus (Acarina: Eriophyidae), was reported to be causing damage first on plantation scotch pine. The mite was then discovered on two other pines, black pine (Pinus nigra), and cluster pine (Pinus pinaster).

The Western Spruce Budworm Strikes Again!

The western spruce budworm (Choristoneura occidentalis Freeman), a native Oregon insect, is the subject of discussion. The author addresses the history of the pest in Oregon, life cycle, damage caused, controls, and plans to implement a spray program.

'Autumn Blaze' - New Callery Pear Introduction from Oregon State University

Breeding and Selection
Callery pear (Pyrus calleryana) cultivars are the subject discussed after the introduction of a new cultivar, 'Autumn Blaze', to the nursery industry. The characteristics of 'Autumn Blaze' are addressed along with information regarding other Pyrus calleryana cultivars.

Branching of Photinia X Fraseri in Response to Atrinal and Other Growth Regulators

The use of growth regulators in the greenhouse or nursery to chemically prune plants was studied, specifically Atrinal applied to Photinia x fraseri, in an effort to determine the effect on branching habit and height of the plant. The methods and results are discussed.

The Chemical Basis for Resistance of Certain Rhododendron Cultivars to Foliar Feeding by Root Weevils

Breeding and Selection
Studies were conducted to determine if there was foliar feeding resistance to root weevils in certain rhododendron cultivars. The results, suggesting the lepidote branch had more resistant cultivars than the azalea branch, are thoroughly discussed by the author.

The Woolly Apple Aphid Eriosoma Lanigerum

A discussion about the apple tree pest, the woolly apple aphid (Eriosoma lanigerum), by an Oregon State University affiliated entomologist. Topics include; descriptions, behavior, association with canker, life cycle, natural control, and chemical control.

Apple Maggot (Rhagoletis pomonella)

The apple maggot was detected on a homeowner's tree in the Portland, OR area in the late summer of 1979 and was again detected on other noncommercial plantings the following year. Apple maggot hosts, damage, detection and control are addressed by the author.