A cabbage seed field in the mid-Willamette Valley. Photo credit: Aaron Becerra-Alvarez/Oregon State University.
Vegetable specialty seed production is a cornerstone of agriculture in the Pacific Northwest. More than 170 seed crops — including brassicas, spinach, radish, carrot, onion and many others — are grown on relatively small acreages but generate high farm-gate value and supply global markets.
These crops do not compete well with weeds. Even low weed pressure can reduce seed yield, seed purity and marketability. At the same time, growers face limited herbicide options for many seed crops, rising labor costs that constrain hand weeding, increasing concern about herbicide resistance, and a shortage of region-specific research on cultural practices and new weed control technologies.
Without targeted research and coordinated support, producers risk reduced competitiveness, lower seed quality and greater production uncertainty in an industry estimated to exceed $50 million in farm-gate value across the region.
Practitioners Identify Top Challenges
In response, Aaron Becerra-Alvarez, an assistant professor in the Oregon State University College of Agricultural Sciences and Extension specialist in weed science in vegetables and specialty seed crops, surveyed specialty seed practitioners across key production regions in Oregon and Washington to identify priority weed management challenges and research needs.
Respondents included growers, crop advisors, seed industry representatives and researchers, many with decades of experience in specialty seed systems. The survey asked which crops and weeds pose the greatest challenges, which management tools are most relied on, and what types of research and new solutions the industry needs next.
The survey results pointed to consistent pressure points. Practitioners most often named brassica seed crops, spinach and radish as the crops with the greatest weed management challenges.
They most frequently identified shepherd’s purse and other weedy Brassicaceae species as top problem weeds — a concern amplified by the close relationship between these weeds and key seed crops, which can limit effective control options and host plant diseases.
Respondents reported that herbicides remain the primary weed management tool, and more than 90% prioritized herbicide research. At the same time, many flagged herbicide crop injury as a significant challenge, underscoring the need for research that improves efficacy while reducing injury risk, including the potential for herbicide carryover in diverse rotations.
Findings Point to Research and Regulatory Needs
Respondents also expressed strong interest in nonchemical approaches, but they emphasized that the region lacks applied research on how cultural practices such as rotations and cover crops affect weeds in seed systems.
They also noted the need for independent evaluation of emerging technologies — such as precision cultivation and other “smart” tools — to determine whether they are effective and economical across the wide range of seed crops grown in the Pacific Northwest.
By documenting weed management priorities directly from practitioners, the study provides a roadmap for action that agencies, industry partners and research programs can use to accelerate practical solutions.
For example, the findings help guide investment in specialty crop herbicide research that improves control of top problem weeds while reducing crop injury. They also support coordinated efforts to expand legally available tools for specialty crops through programs such as USDA-IR4 and state Special Local Need labels, which can help bring new uses to small-acreage, high-value seed crops.
The study also points to a need for stronger monitoring of herbicide-resistant weeds that can move through rotations shared with agronomic crops, protecting both seed crop production and the broader agricultural landscape.
Just as important, the survey clarifies where nonchemical solutions need applied research. Evaluating weed control technologies and testing integrated practices such as cover cropping and crop rotation strategies in specialty seed systems can help growers reduce reliance on scarce labor for hand weeding and improve long-term resilience against resistance.
Public Value
Specialty seed production supports rural economies, agricultural diversity and global food systems. Because seed crops are often grown on small acreages, they can be underserved by private-sector research and product development, increasing the importance of public research and Extension partnerships.
This study offers clear direction for targeted investments that protect seed quality, reduce risk for growers and strengthen integrated weed management across diverse cropping systems.
Aligning research, Extension education and regulatory pathways around industry-identified needs helps sustain farms and seed companies, supports jobs in rural communities, and reinforces the Pacific Northwest’s role as a global leader in high-quality specialty seed production.
Read more from Oregon State University here.