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Hemp

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OSU Extension provides science-based resources to support Oregon hemp growers with production, pest management and regulatory guidance. We offer research, field trials and technical assistance to help producers navigate this evolving crop and make informed decisions.

Latest content

Virus-like Organisms and Viroids in Hemp in the Pacific Northwest

OSU Extension hosted a Hemp Disease Workshop where this presentation took place. The event was created in support of the Western IPM Grant.

Dr. Hannah Rivedal | Apr 2025 | Video

Weed competition and the critical weed-free period in hemp

For hemp growers, controlling weeds is crucial to producing a successful crop. Keeping a field weed-free for a certain period while plants are establishing is important for bud yield.

Matthew Cutulle, Govinda Shrestha | Aug 2024 | OSU Extension Catalog Peer reviewed (Gray level)

Hop latent viroid in hemp

Hop latent viroid (HLVd) is a pathogenic RNA particle first reported in cannabis plants in California in 2019. It has since been reported in cannabis growing in Oregon, Washington, and Canada. HLVd is common in hop plants and...

Cynthia M. Ocamb | Aug 2024 | OSU Extension Catalog Peer reviewed (Gray level)

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Crop management resources

What is the optimum spacing for hemp plants?

What is the optimum number of hemp plants per acre? The answer depends on what it's being grown for. Fewer plants produce more prized colas or clusters of buds, while denser plantings yield more extractable cannabinoid.

Richard Roseberg | Jun 2022 | OSU Extension Catalog

General grain hemp production guidelines in Oregon

Unlike hemp grown for flower or CBD, grain hemp can easily fit into customary annual cropping systems currently practiced in Oregon.

Don Wysocki, Govinda Shrestha, Alan Wernsing | Jul 2024 | OSU Extension Catalog Peer reviewed (Gray level)

Optimum irrigation for CBD-type hemp plants in the field

This article discusses irrigation recommendations for hemp grown for cannabinoid production (CBD type), but not hemp types bred for grain or fiber production.

Richard Roseberg | Jul 2024 | OSU Extension Catalog Peer reviewed (Gray level)

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Statewide Needs Assessment for the Hemp Industry in Oregon

What do Oregon's hemp growers need in terms of research and outreach to help the crop succeed? This study identifies and prioritizes research and educational needs.

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Pest management resources

How to minimize crop loss in hemp from beet leafhopper and beet curly top virus

How to reduce hemp crop losses to beet curly top virus.

Govinda Shrestha, Cynthia M. Ocamb | Jul 2023 | OSU Extension Catalog

Management of powdery mildew on hemp in the Pacific Northwest

Powdery mildew has surfaced as a challenge for Northwest hemp growers. Powdery mildew coats the leaves of hemp plants and leads to a decline in quality. Here's what hemp growers can do if powdery mildew turns up.

Cynthia M. Ocamb | Aug 2022 | OSU Extension Catalog

Biological pesticide shows potential for controlling corn earworm

Study suggests the biological pesticide Gemstar LC helps control corn earworm in hemp plants.

Alison Merkle, Govinda Shrestha | Oct 2023 | OSU Extension Catalog

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Plant disease management

How to control Sclerotinia and Botrytis diseases in hemp

Hemp canker and gray mold management includes cultural control practices to improve air circulation and minimize leaf wetness. Proper plant spacing, plant pruning and irrigation timing help accomplish this. If Sclerotinia is detected,...

Cynthia M. Ocamb | Sep 2023 | OSU Extension Catalog

What to consider to minimize root rot and damping-off in hemp

In cooler weather, such as what Oregon experienced in June 2023, hemp crops are susceptible to root rot. Here's how you can avoid that problem in your crop.

Cynthia M. Ocamb | Aug 2023 | OSU Extension Catalog

Wilt diseases in hemp and their management in the Pacific Northwest

Hemp is susceptible to fungal pathogens that induce wilt disease that can kill plants. The fungi that cause the disease can survive for years and are easily spread. But there are steps growers can take to prevent it.

Cynthia M. Ocamb | Jul 2022 | OSU Extension Catalog

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OSU Global Hemp Innovation Center

The Global Hemp Innovation Center is home to the world’s leading experts in hemp research. The largest of its kind in the nation, it promises to advance the research of hemp and its market potential across multiple diverse industries and research fields to serve the growing international demand for innovative approaches to food, health, and fiber.

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Harvest management

Aspergillus ecology and mitigation strategies in hemp production

Potential mitigation strategies for Aspergillus in indoor and outdoor hemp cultivation systems.

Qingyang Wang, Cynthia M. Ocamb, Govinda Shrestha | Sep 2023 | OSU Extension Catalog

Corn earworm management in hemp

The corn earworm can cause serious damage to outdoor hemp grown for smokable flower and CBD production in Oregon. Here's what hemp growers need to know to identify, monitor and control the corn earworm.

Govinda Shrestha | Aug 2022 | OSU Extension Catalog

Management of powdery mildew on hemp in the Pacific Northwest

Powdery mildew has surfaced as a challenge for Northwest hemp growers. Powdery mildew coats the leaves of hemp plants and leads to a decline in quality. Here's what hemp growers can do if powdery mildew turns up.

Cynthia M. Ocamb | Aug 2022 | OSU Extension Catalog

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Latest stories

Oregon State leads innovation in hemp research, production and equity

OSU's Global Hemp Innovation Center is the most comprehensive hemp research center in the country.

Feb 2024 | Impact story

Study on serpentine soils helps southwest Oregon hemp grower cut costs without yield loss

The results offered useful insights for other southwest Oregon farmers navigating the complexities of serpentine soils.

Gordon B. Jones | Mar 2023 | Impact story

Oregon State receives $10 million grant to study hemp market in western U.S.

Oregon State University’s Global Hemp Innovation Center has been awarded a $10 million grant from the U.S. Department of Agriculture to define economic opportunities for hemp in the western United States.

Sean Nealon | Oct 6, 2021 | News story

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Meet Our Experts

Govinda Shrestha
Statewide Hemp Extension Specialist and Entomologist for Pest Management (Former)
Gordon Jones
Gordon B. Jones
Extension Agronomist
Don Wysocki
Soil Scientist
Cynthia M. Ocamb
Plant Pathologist
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