Cylindrosporium Leaf Spot or Yellow Leaf on Cherry Cause: Cylindrosporium Padi, a Fungus

Plant Disease
A brief report on Cylindrosporium Padi, a serious fungal disease of cherry seedlings in nurseries. The Oregon State University affiliated author discusses symptoms of the disease, the timeline for leaf spot development, and causes of continued infection.

Rootstocks for Pear: Variability in Calleryana

The authors discuss the popular use of Pyrus calleryana as a pear rootstock. Pyrus calleryana did just as well if not better than Bartlett and Winter Nellis in Oregon State University studies. Included in the discussion are the issues growers were having with the rootstock and several possible solutions.

Leaf Browning and Shedding - Arbor-Vitae and Juniper

Plant disorders
Leaf browning and shedding in juniper and arborvitae are addressed in an effort to differentiate between natural causes and disease in the plants. The three fungi discussed can infect the plants and cause extensive damage, they are; leaf-blight (Didymascella thujina), tip-blight (Coryneum berckmannii) and juniper blight (Phomopsis juniperovora).

Lophodermium Needle Cast

Plant Disease
Research was conducted to gain incite into the fungal disease, Lophodermium needle cast, affecting Scotch pines in the Pacific Northwest. The most susceptible species were considered to be Scotch pine (Pinus sylvestris), red pine (Pinus resinosa), and Monterey pine (Pinus radiata).

Dothiorella Canker of Crab Apple

Nursery Crops
A report of the author's observations concerning Dothiorella canker of crab apples, Botryosphaeria ribis. Symptoms of the fungus are discussed along with other plants the fungus was noticed to be affecting, control methods for the disease are also addressed.

Bacterial Gall Disease on Douglas Fir, Pseudotsuga taxifolia

Plant Disease
Research indicated the disease bacterial gall on Douglas fir was caused by an insect, Cooley's chermes (Chermes cooleyi Gill.). The author offers descriptions of the galls, where they form on the tree, the impact the galls have on trees, and how the insect transmits the disease.

Juniper Decline

Nursery Crops
Junipers were affected by what appeared to be a unknown root disease. Although it was thought to be Phytophthora, because it could not be verified the disease was referred to as "juniper decline". The Oregon State University affiliated authors discuss the disease, it's symptoms, and research being conducted on the subject.

Douglas Fir Needle Cast

Plant Disease
A discussion of Douglas fir needle cast, caused by the fungus Rhabdocline pseudotsugae, as it was an increasing problem at the time this article was written. The author also discusses the fungus lifecycle, symptoms, control practices, and research being conducted on chemical controls.

Insect Problems on Narrow Leaf Evergreens

Several insect pests of narrow leaf evergreen trees are discussed in regard to hosts, lifecycle, the type of damage caused, and control methods for each of the pests. The insects addressed are; the Cooley Spruce Gall Aphid (Adelges cooleyi), pine needle scale (Phenacaspis pinifoliae) and the black pineleaf scale (Nuculaspis californica), and Douglas fir needle midge (Contarinia spp).

Brown Garden Snail

Nursery Crops
The topic discussed by the Oregon State University affiliated author is the brown garden snail and it's impact on the nursery industry. The issue of shipping and receiving plant material is addressed. Suggestions on how to control the snail and information on it's lifecycle are also included.