Live plant imports: the major pathway for forest insect and pathogen invasions of the US

Insects

A discussion about live plant imports as an important invasion pathway for non-native plant pests. The authors discuss the effect of current regulation, the need for updated regulation, and the recent and proposed changes to plant import regulation.

Managing Phytophthora

Plant disease

Oregon State University affiliated author discusses the top 10 tips for preventing disease in nurseries. Specific topics addressed include site selection and drainage, sanitation practices, disease free plant sources, plants in container, and irrigation.

Sudden Oak Death and Phytophthora ramorum

Disease

A comprehensive guide for forest managers, Christmas tree growers, and forest-tree nursery operators in Oregon and Washington on sudden oak death, the disease caused by the recently introduced Phytophthora ramorum.

Genetic Methods for Mitigating Invasiveness of Woody Ornamental Plants: Research Needs and Opportunity

Breeding

A review of the different means by which the potential for invasiveness in woody ornamentals can be reduced using genetic methods. Progress is reviewed in conventional breeding and transgenic biotechnology approaches to producing sterile forms of ornamental woody plants.

A Simple Chromosome Doubling Technique is Effective for Three Species of Cupressaceae

breeding

A recent report described a simple technique to double Cryptomeria japonica chromosomes. The objectives of this research was to evaluate the effectiveness of the technique and determine optimal treatment duration for doubling chromosome numbers in oriental arborvitae, american arborvitae, and western red cedar.

Oryzalin-induced Tetraploidy in Crytomeria japonica (Cupressaceae)

Breeding

Japanese-cedar (Crytomeria japonica) performs well under a range of soil and environmental conditions but has been underused in landscapes, in part, due to winter browning. In previous studies, chance seedlings that did not exhibit winter browning were identified as tetraploids. This study was conducted to induce polyploidy in Crytomeria japonica.

Bred for Success

Breeding
Oregon State University professor Ryan Contreras discusses the Nursery Crop Breeding Program at OSU and the current research being conducted into woody landscape cultivars with reduced invasive potential, increased disease resistance, and increased abiotic stress tolerance.

Feeding Through the Leaves

Christmas Trees
Research was conducted at Oregon State University North Willamette Research and Extension Center with the objective of determining whether the addition of foliar fertilization would benefit a Christmas tree plantation or container-grown conifer operation.

The Effects of Methyl Bromide Alternatives on Soil and Seedling Pathogen Populations, Weeds, and Seedling Morphology in Oregon and Washington Forest Nurseries

Disease
Fumigation treatments (a conventional methyl bromide – chloropicrin application and reduced-rate alternative fumigant treatments) and a nonfumigated treatment were evaluated at forest nurseries in Oregon and Washington for their effects on soil pathogen populations, weeds, and seedling morphology.

Influence of Isolation Method on Recovery of Pythium Species From Forest Nursery Soils in Oregon and Washington

Disease
In an attempt to identify Pythium species (common dampening off pathogens) associated with forest nursery soils, field surveys were conducted at three forest nurseries (two in Oregon and one in Washington) in 2008 using three isolation methods.

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