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.

'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.

Leaf Necrosis - Defoliation

Plant disorders
The Oregon State University affiliated author discusses leaf necrosis, specifically two of the frequent causes of leaf necrosis and/or defoliation. Water and heat stress, and 'anthracnose' are addressed in relation to their contribution to leaf necrosis and/or defoliation.

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.

Pear Rootstocks - General Characteristics, Principle Limitations

A table put together by Robert Stebbins, an extension tree fruit and nut specialist in affiliation with Oregon State University. The table provides information on a variety of pear rootstocks, the general characteristics of the rootstock and limitations of the rootstock.

Symptoms and Control of Botrytis on Statice

Plant Disease
Botrytis blight, a plant disease caused by Botrytis cinerea Pers. ex Fr., on statice (Limonium sinuatum Mill,) was studied by the University of Florida. The following topics are discussed; symptoms, seeds, field planting, and cultural and chemical control.

Heat Dispersion of Fungicides - Powdery Mildew Eradicated

Fungicides new to the market in 1979 were tested for effectiveness of control over rose powdery mildew and also tested for control of powdery mildew on a wide variety of other crops. Effectiveness of the fungicides, methods, and fungicide use in the greenhouse are discussed.

Fertility and its Relationship to Turfgrass Diseases

The importance of the relationship between fertility, turfgrass, and turfgrass diseases is discussed. The author focuses on turfgrass diseases common to the Pacific Northwest and offers recommendations for fertilizer practices to help combat the diseases.

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.

Progress in Tissue Culture Propagation of Ornamentals

Plant propagation
Research was conducted on the propagation of rhododendron, apples, raspberries, strawberries, lily bulbs, iris bulbs, Kalmia, Daphne, and arctostaphylos by tissue culture at the Northwestern Washington Research and Extension Unit.