Plant Diseases

Melodie Putnam in the Plant Clinic

OSU Plant Clinic

Online Resource

The Oregon State University Plant Clinic is a diagnostic facility associated with and housed in the Department of Botany and Plant Pathology. The Plant Clinic has been operational since 1954. As part of the OSU Cooperative Extension Service, the primary mission of the Plant Clinic is educational. Extended education is provided by helping our clients recognize the nature of their plant problem (diagnosis) and by helping them to manage the disease or disorder using proper control methods, including cultural, biological, and chemical measures. Emphasis is on prevention of problems by proper management.

By Melodie Putnam

2018 PNW Plant Disease Management Handbook

OSU Extension Catalog

A comprehensive guide to plant disease management in the Pacific Northwest. Includes materials and tactics suitable for organic production and homeowner use as well as for commercial production. Covers testing services, common pathogens (e.g., nematodes, viruses, fungi, and bacteria, as well as...

By Cynthia Ocamb, Jay Pscheidt

Protect Oregon’s Brassica Crops: ODA’s black leg rules aim to control a disease outbreak


Black leg is a serious disease of Brassica crops that has recently appeared in outbreaks in western Oregon. It threatens Brassica production in the Pacific Northwest. In an effort to manage the...

By Nick Andrews

What's killed my tree?


Are you one of the many woodland owners noticing continued signs of drought on your property? Drought impacts are complex; drought stressed trees become susceptible to insects and diseases that are naturally present (typically at low levels) in our woodlands. Take these four steps to help you identify what factors might be impacting your tree health:

By Norma Kline

Blueberry viruses in the Pacific Northwest and suggestions for their management


The goal of this article is to provide a review of the viruses of blueberry that have been reported in the Pacific Northwest (PNW) and highlight those of major concern in the region. Blueberry scorch virus, Blueberry shock virus, Tomato ringspot virus, Blueberry fruit drop associated virus and Blueberry mosaic associated virus are the major viruses that will be discussed.

Fungicide Groups, Modes of Action & Effective Pathogen Control


Fungicide resistance is a serious problem

By Cynthia Ocamb

What’s Wrong With My Madrone?


This article briefly discusses the most prevalent madrone disease problems, then offers a broader perspective on the health of this southern Oregon native.

By Max Bennett, Dave Shaw

Mummy Berry

Blueberry bacterial and fungal diseases


Pacific Northwest blueberry growers must identify and control a number of bacterial and fungal diseases in order to ensure the highest yields possible (profitable yields). Fortunately, only a few of the diseases that occur on highbush blueberry in this region cause significant losses when left unchecked.

By Jay Pscheidt

Know Your Forest - Forest Health

Online Resource

Maintaining a healthy forest is an important objective for most forestland owners.

Know Your Forest Learning Library

Online Resource

Looking for practical information about managing your forestland? You’ve come to the right place. We’ve put together an extensive library of resources to help you reach your goals.