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

Bulbs
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.

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.

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

Insects
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.

Anthracnose-One of the Enemies

Plant Disease
The fungal plant disease "Anthracnose", Gloeosporium nervisequum, occurs when the conditions are favorable for fungus growth and a suitable host is available. The author describes the various symptoms of the disease and provides a partial list of susceptible hosts.

Special: Dogwood Diseases

Plant Disease
A discussion of dogwood (Cornus florida L.) diseases and their impact on the growth of the shade tree which could have an effect on the market value of the tree. Diseases discussed include; foliar diseases, viruses, twig blights, root rots, cankers, and a few other important diseases.

Chlorination of Water

Irrigation
Oregon State University affiliated author James Green, Extension Ornamental Specialist, discusses the practice of chlorinating water. Included in the discussion are characteristics of; chlorine, salts of hypochlorous acid and other chlorinating compounds.

Detection & Control of Pathogens in the Water

Irrigation
The authors discuss the importance of water quality in regard to irrigation water, the source of the water used, and the various pathogens it could contain. Detection of pathogens in water, control methods, and a titration method for chlorine content are addressed.

Special: Plant Injury Caused by Sawdust and Barks

Media
The use of sawdusts and barks in media mixes and mulches is addressed by the Oregon State University affiliated author. The results of tests conducted to test the phytotoxic effects of two species of fresh bark are discussed along with recommendations.

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