Oregon State University has a long tradition of supplying the nursery and greenhouse industry with science-based resources to benefit producers in Oregon.

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The PNW Nursery IPM Website is designed to be dynamic, allowing growers and pest management professionals to give and receive information regarding pest activities in nurseries in the Pacific Northwest.

The OSU Landscape Plants website contains images, identification details and information on over 1,700 mostly woody, ornamental and native plants.

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Production and Management

Greenhouse Grower Magazine

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May 1, 1981
The dangers of tank mixing pesticides are addressed by the University of California affiliated author. The factors discussed include; chemical incompatibilities, physical incompatibilities, general principles for mixing pesticides, specific mixtures to avoid, and causes of phytotoxicity.
June 1, 1973
The history and impact of entomology research conducted in affiliation with Oregon State University is discussed by the author. Topics include; holly and camellia scales, gladiolus viruses, holly insects, pear root aphid, symphylans, tent caterpillars, and control of virus spread.
February 1, 1958
Survey of horticultural crop growers 1955 which included nurseries, florist crops, bulbs, rhizomes, corms, and holly. The author also looked at leading counties in specialty crop production in Oregon.
July 1, 1981
Root weevils can be a serious pest for Oregon growers of ornamental plants, the root weevil feeds on more than 100 plant species. The author offers a brief but informative discussion on the life cycle, root and foliar feeding, control of adult root weevil, and larval control.
November 1, 1975
A brief history of the invasive pest European pine shoot moth, Rhyacionia buoliana (Schiff.), in Oregon. Surveyed Oregon counties found to have infestations were; Clackamas, Lane, Marion, Multnomah and Umatilla. Control methods for the moth are discussed along with descriptions of the life cycle and damage caused by the moths.
March 1, 1959
Several varieties of walnut rootstocks were tested in a study to find suitable rootstock with the hope of preventing blackline disease. The author provides background information about blackline disease in Oregon and it's impact on growers.
November 1, 1981
The idea of using clones in the Christmas tree industry is debated by the Oregon State University affiliated author. The use of clones could lead to more uniform sellable trees but could also lead to a lack of genetic diversity in the Christmas tree industry.
April 1, 1976
Tomato seedlings grown in greenhouses and garden centers were observed to be affected by bacterial speck , a leaf spot that could lead to defoliation and unsellable plants. The disease is caused by Pseudomonas tomato and was thought be carried on the seeds.
December 1, 1959
Clematis grown at Lewis-Brown Farm in Corvallis, Oregon was observed over a ten year period. The author includes a table showing bloom periods for each variety tested in the study.
January 1, 1982
The Oregon State University affiliated author discusses the use of computer modeling and simulation of plant development. The discussion includes various different ways growers could use the technology to improve multiple aspects of their operation.
July 1, 1976
Ideas for how to conserve energy in greenhouses are discussed by the Oregon State University affiliated author. The type and conditions of materials used can affect the amount of heat lost, light conservation is also briefly discussed.
August 1, 1961
Croft lily growers could use the bulblets to increase their stock quickly. Research conducted on Croft lilies production examined the conditions that produced the best bulblets, the results of the research are discussed by the Oregon State University affiliated authors.
July 1, 1982
A method for producing 'mini-trees' for commercial production in the nursery environment. The author discusses how the 'mini-trees' are produced, packing and transport, second-stage nursery and field establishment, the scope for mini-trees in the tropics, and a project proposal.
December 1, 1976
A report on the discovery of a bacterial leaf-spot, a species of Pseudomonas, on cuttings of two different Red maple varieties, 'October Glory' and 'Red Sunset'. The author discusses symptoms of the disease and possible control measures.
May 1, 1963
Research was conducted at Oregon State University affiliated Lewis-Brown Farm in Corvallis, OR on crab apple cultivars to identify which ones possessed desirable traits for ornamental horticulture. Recommendations for which cultivars to grow in the Pacific Northwest along with performance data on blossom and fruiting periods are provided.
Research was conduced on the effect of using a clay-amended substrate to improve nutrient and water efficiency for plants in containers. The presentation includes detailed results on the performance of the different plants used.
June 1, 1977
The author discusses cankers on woody plants, caused by either a bacterial or a fungus. Descriptions of cankers, how and where cankers form, and life cycle are all addressed. While control varies from plant to plant, the author does offer general canker control guidelines.
January 1, 1965
Several deciduous shade trees were studied at North Willamette Experiment Station, Oregon in an effort to determine tree growth rates, tolerance to growth regulators, nematicides, and herbicides.
April 1, 2008
A study was conducted involving Hydrangea macrophylla ‘Merritt’s Supreme’ to determine whether nitrogen (N) fertigation rates applied during vegetative growth and spray applications of urea in the fall influences plant growth and flowering during forcing.
December 1, 1977
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.
June 1, 1965
Experiments were conducted on Nellie White Easter lily bulbs to determine plant response to the order in which the bulbs were preheated, pre-cooled, and held. The bulbs were dug from the Pacific Bulb Growers Research and Development Station in Harbor, OR and brought to Corvallis, OR for testing.
August 1, 1978
An update on research that was conducted in Black vine weevil control based on what had been on going research for black vine weevil control for both larva and adult. The researchers discuss their results and offer control tactics they found successful.
December 1, 1966
A program was developed after an increasing amount of rose rootstock varieties became infected with viruses that were being transmitted to the cuttings during propagation. Recommendations are given by the author on how to approach the rose virus problem.
March 1, 1979
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.
November 1, 1069
Research was carried out on the deficiency symptoms of rhododendrons. The study was prompted by the lack of information on descriptive symptomatology in available literature, the results are discussed by the author.
September 1, 1979
Studies were conducted to test the resistance of rhododendron species to foliar feeding by the obscure root weevil. The author discusses the results of the rhododendron study and addresses the importance of studying plants resistance to insects.
June 1, 1971
The future of research and extension work in the ornamental industry at Oregon State University is discussed by the author. Research and extension staff worked to identify areas in need of research and established priorities with in those areas.
August 1, 1957
Author addresses the problem of "summer sprouting" in Croft lilies fields in southern, coastal Oregon. The 1955-56 experiments to control sprouting using temperature in the greenhouse are also briefly discussed.
May 1, 1981
A study of container media was established to determine and compare the water retention and aeration properties of the various mixes used. The following materials were combined into different mixes; peat, coarse sand, bark, fine sand, and sawdust.
December 1, 1973
The results of 35 years of horticultural research in nursery and ornamental crops conducted at and in affiliation with Oregon State University are discussed. Topics include; defoliation problems, gladiolus, new crop development, lilies, holly, wood waste utilization, ornamental plant nutrition, graduate research assistance, rose and tree fruit rootstock research, ornamental research, root regeneration, propagation research, and plant growth research.
May 1, 1958
Azalea leaf gall disease and leaf spot disease were studied in an effort to find an effective control for the problematic diseases. Different varieties of azaleas were tested by spraying the plants with several different fungicides.
September 1, 1981
Studies were conducted to determine if there was foliar feeding resistance to root weevils in certain rhododendron cultivars. The results, suggesting the lepidote branch had more resistant cultivars than the azalea branch, are thoroughly discussed by the author.
November 1, 1975
A report on the progress of research to find a control for Phytophthora illicis in cut holly and holly plants in the field. The results of the two year study suggests a viable control for Phytophthora illicus once it is detected but not for use in prevention of the fungus. The authors discuss their goals for the ongoing research.
March 1, 1959
Cherry tree rootstocks were studied in various sections of the United States. The Oregon State University affiliated study worked to determine what each rootstock had to offer in terms of growth, cherry productivity, and longevity.
November 1, 1981
Studies were conducted to test the effectiveness of using a hot-callusing device when grafting a variety of different trees. The authors discuss the results of the hot-callusing method and it's effects on apple, peach, pear, prune, and Douglas-fir trees.
May 1, 1976
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).
May 1, 1960
The effectiveness of various treatments for control of powdery mildew was tested on 360 rose plants. The three varieties of roses used in the study were chosen because of their susceptibility to powdery mildew.
January 1, 1982
Research was conducted on the effectiveness of using P-IBA as a rooting-inducing agent for the propagation of cuttings. Cuttings of two rhododendron cultivars, 'Ramapo' and 'Roseum elegans' were used in the experiments, the methods and results are discussed.
September 1, 1976
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).
January 1, 1962
Pear fire blight and pear decline are discussed in relation to rootstocks, trunk-stocks, scions, fruit production, fruit quality. The author offers insight into studies conducted on pear trees in Oregon and Washington.
January 1, 1983
Computers were making their way into the nursery environment for everyday use and improved efficiency. Electronic marketing using a computer auction network, how it worked, the benefits involved, and other markets that were using electronic marketing are addressed by the author.
December 1, 1976
The Oregon State University affiliated author focuses the discussion on pest control in garden roses. Specifically addressed are symptoms and controls for "Black Spot", "Powdery Mildew", and "Rust". The three diseases are found on the leaves and new growth of the plants.
May 1, 1963
Croft Easter Lilies were studied at the Pacific Bulb Growers Research and Development Station in Harbor, OR in an effort to determine the effect of disbudding on lily bulb size.
January 1, 1983
A discussion about the wholesale nursery-greenhouse industry and the idea of using a computer auction network to increase plant transportation efficiency. The author addresses the process involved, "plant locator", "central computer", and other industries using a similar system.
June 1, 1977
Research was conducted on the obscure root weevil (Sciopithes obscurus), the main foliar feeding root weevil in Oregon, on rhododendrons in an effort to determine the biology and control for the weevil. It was the intention of the authors to provide information on control of the pest.
January 1, 1965
Following the success of a previous study to propagation Old Home pear (Pyrus communis) cuttings, experiments were conducted on several other Pyrus species. Two different propagations methods were tested on the various Pyrus cuttings.
September 1, 2008
Rhododendron (Rhododendron ‘H-1 P.J.M.’) and azalea (Rhododendron ‘Cannon’s Double’) were grown with (+N) or without (N-deficient) nitrogen (N) from May to September to determine the effects of N-availability on uptake, demand, and allocation of other mineral nutrients.
December 1, 1977
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.
June 1, 1965
Materials were tested to determine a suitable control for crown gall and black mold. The various materials were tested on Mazzard cherry seedlings after they were dipped in Agrobacterium tumefaciens.
November 1, 1978
A discussion about English holly regarding fertilization suggestions made by A.N. Roberts and R.L. Ticknor in their previously published paper on commercial production of English holly in the Pacific Northwest. The author discusses the recommendations made by Roberts and Ticknor.