Location: Forage Seed and Cereal Research Unit
2023 Annual Report
Objectives
Objective 1. Assemble and integrate current hemp related data and collect new data in collaboration with University partners to establish and improve hemp production modeling efforts.
Objective 2. Develop modeling techniques that incorporate existing and newly generated hemp agronomic information into decision support tools to help farmers integrate hemp production into existing farm systems.
Approach
Industrial hemp is a potentially useful crop for production within the U.S. Various properties and uses for hemp are being explored, some focused on the unique properties of the plant itself (fiber production, protein content as livestock feed), and some focused on the properties of cannabidiol (CBD) for a variety of uses. The goal of this research will be to use existing agronomic information and generate new information, then use modeling techniques to incorporate that information into decision support tools to help farmers integrate hemp production into existing farm systems.
Progress Report
A challenge for agronomic practices of industrial hemp production is pathogen identification and disease management. The regional survey that was initiated in 2021 continued through the 2022 growing season. This survey is in support of Objective 1 and was conducted with collaboration from Oregon State University faculty members and industry personnel. Over both years of the survey, we evaluated 79 production fields at up to three time points (early, mid, and late-season) throughout the Pacific Northwest (PNW). All data generated from these surveys will be utilized in future modeling efforts by the vacant scientist position.
In 2022, we found similar incidence of powdery mildew as in 2021. Powdery mildew was active on hemp late in the season (August-September). We detected both the hemp powdery mildew pathogen (Golovinomyces ambrosiae) and the hop powdery mildew pathogen (Podosphaera macularis) on PNW hemp in 2021 and 2022 which has management implications for hemp and hop growers. Efforts to screen hemp germplasm for resistance to these pathogens, and to understand the interplay between a hemp infection near hop yards and vice versa, are underway.
As in 2021, we detected beet curly top virus (BCTV) in 2022 hemp crops. This virus is transmitted by beet leafhoppers to over 300 crops and weedy hosts including industrial hemp. We detected BCTV broadly, in 87 percent (%) of surveyed fields using virus-specific polymerase chain reaction (PCR) primers. We determined that 95% of detections were Worland-like species of the virus, and further sequencing evaluation is underway to identify the specific population of BCTV species associated with PNW hemp. Studies screening germplasm for potential tolerance to the virus, and an evaluation of landscape factors like weed diversity and nearby crop hosts on virus incidence and severity in hemp are in development. In addition to BCTV, other organisms transmitted by leafhoppers, like phytoplasmas, have been detected in PNW hemp. A greater understanding of how important hemp is for creating new sources of virus for leafhoppers to transmit throughout the region is critical to the overall health of the PNW cropping system.
In addition to pathogens, we surveyed for nematodes in industrial hemp fields. Plant-parasitic nematodes (PPN) are a challenge to control in most other cropping systems and there has been some prior research indicating that planting hemp can reduce populations of PPN. We have documented the first report of Pratylenchus penetrans infecting hemp in the United States (manuscript in press). Inoculation experiments documenting the interaction between P. penetrans and other soilborne pathogens, like Fusarium spp., are underway.
In support of Objective 1, a nation-wide network of cooperators organized by Oregon State University conducted a uniform cultivar trial of chemical, grain, and fiber-type hemp varieties. General observations were made determining the suitability of these genetic materials grown under production conditions typical of the regions. Establishment systems leading towards commodity production were used and evaluated for continued suitability. Local climatic/weather, edaphic, disease, insect, and weed stressors were assessed and plant growth measures suitable for application to models were taken.
Accomplishments
