College of Agricultural Sciences

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.

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.

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.

Dr. Author Bing, in affiliation with the Long Island Horticultural Research Laboratory in Riverhead, NY, addresses the issue of using herbicides in greenhouses. Specifically discussed are several different herbicides and their effect on plant growth.

As the popularity of foliage plants from subtropical and temperate climates increased in the Pacific Northwest, so did the incidences of cyclamen mite (Steneotarsonemus pallidus Banks) infestations. Descriptions and lifecycle of the mite, symptoms of damage, and controls are discussed.

Using mulches in landscaping and gardening environments is the topic discussed by the author. Specific areas addressed are; types of mulch, effect of mulch on microclimate, effect of mulch on soil conditions, and problems in mulch selection.

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.

The University of Florida affiliated author addresses how to avoid pesticide phytotoxicity in ornamental plants. The five most common types of phytotoxicity identified are; burn, necrosis, chlorosis, leaf distortion, and stunting or abnormal growth.

A brief report on the symptoms and lifecycle of several rusts known to attack rhododendrons. The disease first appeared in Oregon in 1955 and had become a serious problem for growers of susceptible varieties by the time this article was written.

Water availability for the upcoming growing season was a concern due to an unusually dry winter. The author discusses the legalities of Oregon water rights regarding greenhouse and nursery crops. Several different types of irrigation permits are addressed along with where to obtain them.