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Washington State University
WSU Puyallup Ornamental Plant Pathology

Emerging Plant Health Issues of Concern


Emerging issues

There are several plant health issues emerging as major concerns in the Pacific Northwest. A few concerns are highlighted below, but we will continue to update this section as new threats to plant health are detected.

More Research is needed

More research is needed because the factors driving these declines are not well understood. For example, changes in the environment and the onset of more frequent, longer and hotter droughts in some areas of the Pacific Northwest will affect the way plants and parasites interact.

It is often difficult to pinpoint the most important factors leading to the decline of species because it is often a complex interaction between organisms and the environment. Changes in the host plant, environment, pest or pathogen, or a combination of changes, can lead to the emergence of novel disease epidemics or pest outbreaks (see Disease Triangle). This complexity is further demonstrated by Manion’s Disease Decline Spiral, highlighting the numerous factors that can interact to drive tree mortality.

Invasive Species and Early Detection

The introduction of exotic organisms into our ecosystems can also drive irreversible change. Many novel disease epidemics and pest outbreaks have arisen from introductions of ‘alien’ or exotic species originating from other areas of the planet. It is therefore possible that the emerging plant health issues highlighted below are consequences of the introduction of an invasive plant pathogen or pest, but more research is needed.

Disease Triangle
Disease decline spiral
Disease decline spiral from: Manion, P. D. 1991. Tree disease concepts. Second edition. Prentice-Hall, Inc., Englewood Cliffs, New Jersey.


Plant Health Concerns

Share Your Concerns

Have additional concerns?

We encourage you to share your concerns with with your regional WSU Extension Forester or by filling out the webform on the right.

We will do our best to provide programming and information to address your concerns.

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