Differential Feeding on Rhododendron by Adult Root Weevils

Field studies were conducted to determine if adult root weevils feed on certain cultivars of rhododendron more than other cultivars. The author discusses the methods and results of the studies, including the difference in resistance of the cultivars used.

Research Update on Crown Gall and Hairy Root Disease in the Northwest

Plant Disease
Progress report on research conducted on crown gall and hairy root disease in the northwest. Noninfectious hairy root on apples, the effect of crown gall on boysenberry production, and biological control of crown gall on fruit and shade trees are discussed.

Transmission and Control of Plant Diseases in Propagules

Plant propagation
A discussion about propagation and the transmission and control of plant diseases. The topics addressed in relation to propagation and plant disease include; significance of propagule transmission, control procedures, bulbs and corms, and seeds.

Narcissus Smolder in British Columbia

A discussion involving Narcissus Smolder (Botryotinia narcissicola) in the Pacific Northwest focused mainly on British Columbia. The author describes the disease, discusses the impact it had on the Narcissus industry in British Columbia and addresses control strategies.

Pear Trellis Rust Under Control in British Columbia Mainland

Plant Disease
A survey and eradication program was put into place after pear trellis rust (Gymnosporangium fuscum), was found in the Frasier Valley, British Columbia in 1972. A pear and juniper quarantine was imposed in the area in an effort to gain control of the disease.

Foliar Fertilization of Flower Bulb Crops - A Trial and Some Thoughts

Foliar fertilization trials were conducted on tulips, Iris, and Narcissus to determine the effectiveness of a foliar fertilization spray on the bulb yields. The authors discuss their methods, materials used, and the results of the trial.

Defoliation by Winter Moth - A Pest New to the Pacific Northwest

A discussion about the history and discovery of the winter moth, Operophtera brumata, in Oregon State University and Oregon Department of Agriculture Entomology collections taken from the Portland, OR area. Appearance, damage, and life history are addressed.

Dogwood Anthracnose

Plant Disease
Anthracnose, a leaf blotch caused by the fungus Gloeosporium, was becoming a common disease of flowering dogwood trees in the late 1970's in western Washington. Discussed are the symptoms of the disease, lifecycle, effect on tree growth, and control methods.

The Influence of Stress on Diseases of Nursery and Landscape Plants

Plant Stress
A discussion of the influence stress can have on diseases of nursery and landscape plants. The author addresses the increased susceptibility to disease when plants are weakened by stress, drought or water stress, excess water stress, and high and low temperature stress.

Insects Have Defoliated My Tree - Now What's Going to Happen?

The USDA affiliated author addresses the issue of tree defoliation and re-foliation. Information is provided on the following topics regarding defoliation; the factors that influence tree defoliation, the effects of defoliation, and tree care.