PNW Herbicide Resistance Initiative

Reducing threat of weeds in the Pacific Northwest

With participation from Pacific Northwest land grant universities and three regional USDA-ARS units, the Pacific Northwest Herbicide Resistance Initiative (PNWHRI) provides ongoing support for programs and projects focused on managing herbicide-resistant weeds across the PNW, with a special focus on cereals producing regions.

OSU logo U of I logo WSU logo USDA ARS logo

Problem Statement

The presence of weed seeds in crop fields at harvest affects crop quality, yield, and suitability of agricultural exports. The emergence of herbicide-resistant weeds can fundamentally alter farming practices, forcing less profitable and often less reliable crop rotations, and potentially necessitating the use of tillage practicies known to adversely impact soil health and increase erosion. Furthermore, the inadvertent blending of grain with weed seeds can contaminate other grain from the region along the export pipeline. Overseas importers use weed seed contamination limits as leverage to block the import of Pacific Northwest wheat.

Goal & Objectives

The goal of the PNWHRI is to create a coordinated, interdisciplinary, systems-based approach to managing herbicide resistance in weeds that is regional in scope and long-term in impact.


Biological Characterization

Develop system adaptive capacity by refining best management practices based on fundamental biology of weed species into a management toolbox that is incorporated into a real-time climate-based decision support system


Socio-economics & Policy

Determine the socio-economic and policy-related opportunities and barriers to adopting integrated weed management systems within traditional and aspirational wheat-based systems that impart resilience to weeds (and climate variability and change)


Education and Outreach

Develop an active and engaged extension and outreach program built around fundamental and applied aspects of the Initiative

Supporting Partners

Idaho Wheat Commission
Idaho Grain Producers Association
Idaho Barley Commission
Oregon Wheat Commission
Oregon Wheat Growers League
Washington Grain Commission
Washington Association of Wheat Growers
Far West Agribusiness Association